Southwest B737 Overrun @ Chcago MDW

[Tim_donovan]

CNN Reports 737 off the end of runway 02:03 UTC at Chicago's Midway Airport.

KMDW 090153Z 23003KT 1/2SM SN FZFG VV002 M04/M05 A3004 RMK AO2 SLP191 R31C/4000V4500FT SNINCR 1/10 P0000 T10391050


:ugh:

[con-pilot]

It was Southwest, unsure of flight number. Live on CNN.

No injuries reported as yet, it was on landing. Very heavy snow falling.

Standard stupid statements by reporters. “Why were they allowed to land!” etc.

Flight was coming in from Baltimore, did hit one car.

[cossack]

It was at MDW Chicken Noodle News (http://www.cnn.com/2005/US/12/08/chicago.airplane/index.html)

[Tim_donovan]

Plane slides off runway at Midway

Thursday, December 8, 2005; Posted: 9:03 p.m. EST (02:03 GMT)


Emergency personnel work at the scene where an airliner slid off a runway Thursday in Chicago. CHICAGO, Illinois (CNN) -- A Southwest Airlines jet slid off the runway during a driving snowstorm at Chicago's Midway Airport and slid into at least one vehicle at a nearby intersection on Thursday night, a spokeswoman for Chicago's Department of Aviation said.

Flight 1248, which was arriving from Baltimore, slid through a fence separating the runway from the intersection, spokeswoman Wendy Abrams said. There were no immediate reports of injuries.

[da-bears]

It was SWA at Midway not O'Hare,
Everybody evacuated with two injuries

[Trentino]

dont mean to be nit picky but 'crash' is such a harsh word to use especially if you only see the title and unable to read the rest, could someone maybe change the title to runway excursion?
Maybe im just an alarmist?

[CarbHeatIn]

KMDW 090153Z 23003KT 1/2SM SN FZFG VV002 M04/M05 A3004 RMK AO2 SLP191 R31C/4000V4500FT SNINCR 1/10 P0000 T10391050

KMDW 090137Z 090124 07010KT 1SM -SN BR SCT003 OVC006
TEMPO 0203 1/2SM SN FZFG VV003
FM0300 03008KT 3SM -SN BKN007 OVC012
TEMPO 0305 1SM -SN BR
FM0500 33007KT 5SM -SN BKN010 OVC015
FM0800 33012KT P6SM BKN020
FM1200 29010KT P6SM BKN030
FM1800 24012KT P6SM SCT030


All Paxs and crew on board are safe but apparently a father and child that were in a car that was in collision with the aircraft are "seriously injured". Also appears that the gear collapsed at some point of the roll out.

Not sure of the exact runway alignments at KMDW, but the North-Westerly runway was operational at the time of the incident despite the fact that winds were out of the east.

[con-pilot]

I used to fly 72s in and out of Midway. Even on good weather days the pucker factor was very high. In the heavy snow that is showing on TV tonight, all I can say is MAN!

Just damn glad it wasn’t me. No room for error on that airport for a large (727, 737, 320 etc.) airplane.

PS. Didn’t see the first post said ORD. Yes the accident is at MDW Midway. Runway is 6,255 ft.

Hell it wasn't fun in a Sabre 65, the Falcon 900 or the Falcon 50.

Cardheat, it was the nose gear.

[newarksmells]

Plane is sitting at the traffic lights just outside the airport fence. Nose of the plane is on the ground. Car is under the right engine. 8 inches of snow by 7:00pm tonight. Still coming down very heavy.

Newarksmells

[RRAAMJET]

Trentino, your demeanor is admirable, but it looks pretty 'crashy' to me.
One engine torn-up for sure, nose gear collapsed, cars crushed, leading edge of starboard wing looks bad. Yipes - I've a good friend who's a Capt for SWA in MDW, hope it's not him.

MDW used to scare me to death in the MD-80. :eek:

[CarbHeatIn]

They're now saying on CNN that the FAA have announced the flight skidded off of runway 13C on landing. 13C??? Anyone familiar?

They've now amended this to 31C. 6500 ft.

[con-pilot]

OH MY GOD! I have just heard the ultimate incredibly insanely stupid question by a reporter.

Male reporter; “By all accounts the airplane ran off the end of the runway, through the fence and through the sound barrier.” (The sound barrier he was referring to is an acoustical {sound} barrier fence.)

Female reporter; “The SOUND BARRIER, isn’t that really fast? Why were the pilots flying that fast on landing?”

Male reporter; Long pause, then he explained the difference.

Now that was priceless.:p

[KC-10 Driver]

They're now saying on CNN that the FAA have announced the flight skidded off of runway 13C on landing. 13C??? Anyone familiar?

Not sure what you're asking.

But, there are three 13-31 runways: 13L-31R, 13C-31C, 13R-31L.

Go to to airnav.com (http://www.airnav.com) and enter KMDW to see the runway configuration.

[RRAAMJET]

That would be 31C. That's where the jet is. Bad news wind-component-wise. I would assume that MDW simply had ops aligned with ORD landing direction - not ideal.

Interestingly, AA cancelled earlier flights into MDW due wx, but the -80 is no match stopping-wise for the 737.

[CarbHeatIn]

KC-10, sorry for the confusion, they'd been saying all along that it was a North-Westerly runway and then they come out with 13C. They've now corrected this. Thanks for the link.

[con-pilot]

RRAAMJET, long time no drinks with you. (Need to something about that.)

That was the one really great thing about the 72, great brakes. But on a snow covered runway, at Midway who knows?

[RRAAMJET]

I know for sure I wouldn't try it in an 80. But then we have a big base just up the road, making div. easy; kind of factors into your mindset.

All I can say is, glad I'm not flying tonight in Illinois...poor guys.

[CarbHeatIn]

Now saying 2 cars involved.

[West Coast]

Have heard a few gems from the reporters. I have come to expect them to know little or nothing. What I find sad is that the aviation experts they call upon are no better.

[con-pilot]

Yes Carbheat, early reports (unconfirmed) is that the 73 hit one car and then the other car ran into the airplane (looks like the right engine). The airplane is sitting in a traffic intersection just off the runway.

The four people in the car (that may have been hit by the 73) are in local hospitals and they are in serious to critical condition.

Let us all hope and pray the folks in the car all pull through with little or no serious problems.

[Trentino]

RRAAMJET, I wasnt aware of the extent of the damage.
I feel bad for those pilots, SWA are a cool bunch, always enjoy hearing their banter on the radio.
Out of curiosity does anyone know how many daily cycles SWA has?

[RRAAMJET]

Unbelievable comment here in Dallas from a member of SWA's Go-team - "We had no fatalities on the plane, so that keeps our record intact".

No, but just reported that an 8-year-old boy has died. Shame on them.
:mad:

[Airbubba]

Here's an overhead of the crash site:


http://maps.google.com/maps?q=midway+airport&ll=41.792569,-87.762566&sll=41.836828,-87.626953&spn=0.005297,0.009866&sspn=45.325076,65.126953&t=h&hl=en

Another overhead from the just released Windows Live Local:

http://local.live.com/default.aspx?v=2&ss=midway%20airport&cp=41.792933~-87.76274&style=h&lvl=18&scene=1403109

[ShenziRubani]

very sad news confirmed that one 8 y-o has died from his injuries. Prayers to the families and for the other injured in this accident.

[con-pilot]

I have to agree old buddy. Just heard the child, a 6 year old, just died.

As someone with a 5 year old grandson my heart goes out to the family.

All they were doing was just driving down the road. Just before Christmas.

Aw Hell, its got to get to you.

[PAXboy]

Airbubba thanks for posting the link to the aerial view of Midway. I have never paxed into this field but, looking at the map, my jaw fell open. I have been in City style airports before but - if the slightest thing goes wrong - there is just nowhere to go. To have the runways crammed in to such a residential area and the perimeter road right there? Staggering what people will do for money (i.e. squeezing an airport into the middle of a suburb) I sit to be corrected.

[av8boy]

PAXboy,

I think you'll find that, as with so many airports, the city came to the runways rather than the runways crammed in to such a residential area and the perimeter road right there?

There's a picture of MDW in 1929 on this (http://www.encyclopedia.chicagohistory.org/pages/828.html) page. Note the absence of pretty much everything...

I heard the 13/31 screw up as well. My thought was that it's a good thing the aircraft didn't land on 13C... it may well have hit the White Castle on that corner and the grease fire would still be burning.

I didn't notice whether anyone else pointed it out, but PAXboy's comment reminds me that it's 33 years to the day since the United 737 crash (http://amelia.db.erau.edu/reports/ntsb/aar/AAR73-16.pdf) a mile-and-a-half short of 31L at MDW that killed 45...

[readywhenreaching]

Aircraft involved was N471WN, a -700Winglets version, 1,5 years old

source: www.jacdec.de/news/news.htm

[Jordan D]

BBC News story on the incident, including reference to the accident 33 years ago.

http://news.bbc.co.uk/1/hi/world/americas/4512360.stm

Jordan

[Doors to Automatic]

The landing distance on this runway is around 5800ft due to a displaced threshold. I've been in there once or twice - it's a very tight squeeze.

I'm amazed aircraft like the MD-80 can get in and out. I've also watched a 727 take off from there on a 90 degree day - now that was a sight to behold!

I believe this runway experienced an overrun recently with an ATA 757-300 - the aircraft on this occasion did stay within the airfield boundary.

[ORAC]

Hit two cars, both with passengers.

CNN:

"The 6-year-old boy who died was in the car with his two younger brothers, including an infant, and his parents, said Deborah Song, spokeswoman for Advocate Christ Medical Center in Oaklawn.

Their vehicle was crushed under the nose and fuselage of the plane, said Fire Department spokesman Larry Langford.

The mother, in her 30s, was in good condition; the father, in his 40s, was in serious condition; the 4-year-old middle son was in fair condition; and the infant was in serious condition, Song said.

Four people in the second car, which was under a wing of the Boeing 737-700 jet, were in serious but stable condition.

In addition, three passengers from the plane were in good condition, said Trotter, quoting paramedics.

[M609]

What does the FAA use for RWY condition reporting? Can't find snowtam on the web briefing systems.

[ATPMBA]

I flown into Midway with Lear Jets and HS-125's all without thrust reversers. Off course I had good weather on all the occasions.

Someone said AA canceled their flight, I heard SW held for 30 minutes, why the hold? Any braking action reports?

It's sound like they had "get-there-itis" KORD is only about 15 miles away, they could of landed there and bussed the people to KMDW. SW is point-point so the paxs didn't have to make any connections other than meeting with their loved ones.

Reminds me of an incident several years ago at KBDL where they had 50kts winds at night, AA or UAL diverted to a field 50 miles away, US Air made an approach and barely cleared the ridge line, tree branches went through the engines. Moral of the story, the crew that diverted still have their jobs.


I wonder how SW crews will be acting today as they normally have an in-your-face stupid humor style. An example, a stew was giving the normal pax briefing and the Capt piped in claiming she's my ex-wife. Are they an airline or comedy club? Definetly not PAN-AM.

This is the second overrun SW has had in recent history, in CA they ended up in a gas station several years ago.


My heart goes out to the family of the 6 year old boy, what kind of Christmas will they have?

[bushbolox]

!750metres, i hope they did a pi for the conditions. most of our destinations of that length are basically out when its wet , never mind close to or at cat 3.

[notdavegorman]

That's because you fly the A380. A much larger aircraft...

[UL975]

As this is their second overrun, perhaps SW will no longer preclude the use of auto-brakes! MAY, just have allowed them to ‘get away with it’.

[davedek]

Quote from ATPMBA:

'Someone said AA canceled their flight, I heard SW held for 30 minutes, why the hold? Any braking action reports?'



Perhaps it was holding while the ploughs went out to clear the snow? Perhaps it was not done properly (pure speculation).

[flown-it]

ATPMBA
Reminds me of an incident several years ago at KBDL where they had 50kts winds at night, AA or UAL diverted to a field 50 miles away, US Air made an approach and barely cleared the ridge line, tree branches went through the engines. Moral of the story, the crew that diverted still have their jobs.

Isn't that
1. Pure speculation
2. Off the point
3. Inaccurate...I think another airlines narrow body hit some trees in that part of the world some years ago and got away with it..not much in the news about it. To my knowledge there was not a US Air incident at KBDL in recent memory. Please if relevant supply the links.
Thanks.
Flown-it.

[captplaystation]

The number of sectors operated by these guys, 2 overruns, whilst 2 too many, sounds not such a bad record;ATPMBA (sic) sounds like the stateside equivalent of a Ryanair basher.Their humour, which he very kindly points out will be a bit subdued today, has b*gger all to do with anything (perhaps they smile coz they are treated well?) I feel much safer flying in a happy ship, good CRM/ communication etc. As stated by the previous poster we have no idea why they held for,then eventually landed at, destination, if it legal,& practical that is what we are paid to do for chrissake! Loss of the child,as any parent knows, is heartbreaking at any time,perhaps especially at Xmas, imagine the parents having to deal with previously purchased gifts from Santa, truly ,truly heart-rending.

[lomapaseo]

Relevant only from the part about one airline diverting and the other not

3. Inaccurate...I think another airlines narrow body hit some trees in that part of the world some years ago and got away with it..not much in the news about it. To my knowledge there was not a US Air incident at KBDL in recent memory. Please if relevant supply the links.
Thanks.
Flown-it.



I was aboard the UAL flight coming from ORD-BDL and I assure you we did not divert or abort even though we used the same approach over the tree line. We bumped around some (always fun at low altitude):}

The only difference was that we did not descend below MDH. I saw the AA MD80 the next day in the hangar and it was an eye opener to see the tree branches stuck in the belly skin lap joints.

[pilotusa]

RRAAMJET posted:

"Unbelievable comment here in Dallas from a member of SWA's Go-team - 'We had no fatalities on the plane, so that keeps our record intact'."


I think that SWA attitude, so arrogantly prevalent through the years, is about to be excised so very painfully by the FAA and the media. The darlings are about to become pariahs, at least for the short term.

This should be an interesting investigation. I would not want to be part of the cockpit crew for this one. My guess is that the FAA will manage to pin a large portion of the blame on the pilots. There is never flown the "perfect" approach and landing, but the SWA pilots on this flight will now have to account for their lack of perfection. (Being only human is not an acceptable answer, BTW.)

[RatherBeFlying]

That makes 3 recent overruns, AF358, Teterboro and now Midway, where EMAS could have made a save if it had been there.

[breguet]

In Canada, we used the Canadian Runway Friction Index (CFRI) to help us determine if we can land on contaminated runways.

By assuming there was loose snow on packed snow of 3mm or less, considering that the runway length (from previous posters) is 6255 feet or 5880 feet with the displaced threshold and, assuming a landing distance (not factored) for a 737 of 3000 feet on a dry surface (I do not fly the 737, therefore this distance is an assumption), reading the CFRI chart we find that for these conditions, the CFRI would be between 0.1 and 0.4.

For a 3000 feet unfactored landing distance, we find that we need the following distances to stop the aircraft:

0.18 = 7920ft
0.20 = 7640ft
0.25 = 7060ft
0.30 = 6950ft
0.35 = 6220ft
0.40 = 5910ft

:8

[captplaystation]

RatherBeFlying, agree entirely,but that costs money,crucifying pilot's doesn't.

[Wake Turbulence]

Link to the KBDL incident (http://www.ntsb.gov/ntsb/brief.asp?ev_id=20001207X04839&key=1) which involved an American Airlines MD-80.

[ATPMBA]

Ground school is great but theory can only can take one so far.
I wonder how much experince these guys have on cold weather ops.

Several years ago Air Florida put one in at Washington National, the pilots were talking about doing a "soft-field" takeoff in a B737!!!!

[repulo]

ATPMBA,

doing a soft field take off in a single is adding backpressure to lift the nose gear, exactly what boeing flight crew manual says you should do on contaminated rwy to reduce drag caused by the nose gear.
Not my invention, it´s boeing´s baby.

So better do reading then blameing.

[barit1]

Many years ago I assembled a report re hardware damage from ground-level icing. In a nutshell, the Great Lakes region, esp. Chicago, was among the worst in the world.

And SW has been flying there a long time.

[pilotusa]

barit1 wrote:

"Many years ago I assembled a report re hardware damage from ground-level icing. In a nutshell, the Great Lakes region, esp. Chicago, was among the worst in the world.

And SW has been flying there a long time."


And as we who compete against Southwest have been saying for quite a while: "It's only a matter of time...."

[oliversarmy]

"And as we who compete against Southwest have been saying for quite a while: "It's only a matter of time...."

Its being said about a LCC this side of the pond too !

[av8boy]

I heard SW held for 30 minutes, why the hold?

There was a ground delay program in effect for snow at MDW. I believe SWA took a delay on the ground in BWI, then got two or three turns in the hold at FL300 over northwestern Indiana before starting down.

Dave

[RRAAMJET]

I have to say, in persuit of cheaper airport operating costs, SWA does rather push the envelope in terms of the 'secondary' fields they prefer to operate from:

Islip, Long Island (v. short)
Orange County (ditto)
Midway (ditto)
Houston Hobby (short)

In addition, there seems to be a 'hurry, hurry' air to their ops, eg landing at ELP with large tailwinds to roll right up to the gate. Nothing illegal, but just pushing the envelope, it seems to me. It was just reported by NTSB that this jet landed with a wind from 090 (on rwy31, with contamination....)

Prudence, prudence. :suspect:

[PaperTiger]

KORD is only about 15 miles away, they could of landed there and bussed the people to KMDW. SW is point-point so the paxs didn't have to make any connectionsMDW is a connection/transfer point in Southwest's system. Not a hub like DAL or PHX but busy enough.

As for ORD, I doubt there would have been slots and certainly no gates. A 'local' divert to IND or STL (WN stations) would have been more likely, but if all area WX was cr*p maybe that wasn't a workable option.

[A-FLOOR]

FI now states the plane returned form mainenance only two days ago (one day before the accident):
“The aircraft was released from the airline’s Phoenix maintenance facility on December 7, 2005,� says Southwest. “There were no indications that the aircraft was experiencing any type of maintenance problems.�
http://www.flightinternational.com/Articles/2005/12/09/Navigation/177/203528/Southwest+identifies+737-700+from+Chicago+overrun+tragedy.html

[Flying Mech]

Ok the Wx conditions are a factor in this Incident but the Bigger issue is why did the NLG of an 18 month old A/C collapse on the landing roll. I heard somewhere a few years ago of an Incident like this with a NLG collapse caused by touchdown on the NLG first. Time will tell when the NTSB/FAA have completed their investigations & FDR & CVR have been analyzed. May the 8 year old boy RIP.

[NigelOnDraft]

FM...

From where do you have reliable info the NLG collapsed before the Ac left the runway ????

[PAXboy]

I think that SWA attitude, so arrogantly prevalent through the years, is about to be excised so very painfully by the FAA and the media. It is only to be expected that every new company will reach the point when they have a fatality (direct or indirect). Every transport company and many ordinary ones too, have to face this day. In humans we call it 'growing up' and 'maturing'. Whether the gowing up is being done by humans in their personal way, or by humans as a company, it always has it's horrible times. Hopefully, the child - and the company - become adults and are the better for what they have learnt.

Some individuals - and some companies - never grow up. This usually leads to prison and bankruptcy, or both. This crash and death/s will not harm SWA. It is what they do in the next 12 months and through the enquiry, that will harm them - or see them mature a little.

[captplaystation]

RRAAMJET,sounds like many peoples description of a "little" company on this side of the pond,and sure,pushing ever closer to the limits does leave a lot less in reserve on the occasions when something else happens;don't forget that the last major overrun was Air Chance & I've never heard of them as being described as a lo-co!

[AirRabbit]

Several years ago Air Florida put one in at Washington National, the pilots were talking about doing a "soft-field" takeoff in a B737!!!!
Aww, come on. That Air Florida pilot was not planning to make a “soft-field” takeoff. Go back and re-read the transcript of the CVR. He was talking of taking off the nose wheel and then letting the airplane fly off the ground with very little rotation (only that which would get the nose gear off the ground – like a soft field takeoff).

As has been said, even on this thread, it’s a lot easier to “trash” the crew right away, than it is to wade through all the necessary facts before becoming judgmental. And, as for picking apart what a pilot said … I would suspect that half of the posters on this site would be right embarrassed if some of their “never-intended-to-be-heard-outside-of-the-cockpit” comments ever made the light of day.

The prudent thing to do here is 1) to pray for those injured or killed and pray for their families; and 2) keep our collective critical comments to ourselves until we learn at least some of the facts that were behind the decisions that were made.
________
AirRabbit

[vapilot2004]

'We had no fatalities on the plane, so that keeps our record intact'

I would be willing to bet real money that this quote, if true at all, was made before the deaths on the ground were made public.
It would have been callous and just plain stupid to make such a comment otherwise.

but the Bigger issue is why did the NLG of an 18 month old A/C collapse on the landing roll.

I would say because the landing roll included unapproved surfaces (antennas, light poles, soft grass, ruts, gopher holes - 1 Steel Wall - you get the Idea ?) They went Off the runway Dub !

Latest news I have on the incident has several PAX reporting a runway covered deep in snow - one reported saying "I could not tell the difference between the runway and the grass" This shows contamination beyond what local airport officials are admitting.

[Globally]

I hope we find that the crew flew the approach on speed, landed in the touchdown zone, on centerline, with autobrakes on the proper setting for conditions, reversers and speedbrakes deployed on schedule. Then we would have to find out whether tower reported a braking action code that correlated to the actual conditions, and if that reported braking action complied with SWA operating manuals for continuing the approach and landing.

[ATPMBA]

On December 8, 1972.

[Check 6]

Link to video of crash site (http://www.nynewsday.com/news/nationworld/nation/chi-051208wgnmidway,0,1100713.wmvfile?coll=nyc-nationhome-headlines)

[GlueBall]

Globally with autobrakes on the proper setting for conditions

The autobrakes are OK as long as you can maintain centerline and stay on the pavement. The autobrake logic will not detect any drift off the pavement. In some cases directional control can better be achieved with manual differential braking and differential reverse thrust to arrest runway drift and to stay on the pavement and not go off the side.:ooh:

[Globally]

Glueball. I don't agree with either differential braking or differential reverse thrust in a snowy runway situation. This situation seemed to be a problem with stopping in the available runway, rather than a directional control problem. From my experience flying approaches at night to snow covered runways, it is advisable to land with the maximum autobrake setting, or one below maximum, because of the marginal condition of the runway, allowing the autobrakes to meter fluid to the brakes evenly, immediately after touchdown. Autobrakes solve many problems at night in this situation, because it is impossible to see the runway surface on approach, other than lights. Autobrakes at the highest setting give the benefit of the doubt to the pilot. When manual braking, sometimes a pilot might delay braking or not use maximum braking with so much going on in the cockpit after touchdown - getting the throttles into reverse, monitoring directional control, and checking speedbrake deployment, wasting precious seconds in the process. Autobrakes nearly eliminate one duty out of many immediately after touchdown.

[UL975]

SW precludes the use of auto brakes. Or at least they certainly did in the past. I believed it was to aid in the transition from the -200 to the NG (although every -200 I’ve flown has had it).

SW prefers their crews to operate without the some of the tools we take for granted….VNAV, Auto-Throttle (even during CATIII), Auto-Brakes. None of which are critical, however often go a long way to reducing work load in other wise busy periods of flight. As Globally said ‘Autobrakes nearly eliminate one duty out of many immediately after touchdown.’

Not to allow the use of them is madness.:confused:

[PPRuNe Radar]

As this is their second overrun, perhaps SW will no longer preclude the use of auto-brakes! MAY, just have allowed them to ‘get away with it’.

Third party reports I have received also suggest 'No Autobrakes' is SOP at SWA. Be interesting to see whether they were used in this incident or not ... scary if not !!!

Have flown SWA a few times and enjoyed the service a lot. A great model for a lo-co airline.

But meanwhile, there has to be some sympathy for our flying brothers in this tragic accident, but let's not forget that innocent members of the public suffered even more so. Rushing to protect and deflect criticism against anyone involved is trivial compared with the car pax and drivers families loss. RIP.

[Globally]

UL 975. Agreed. I am surprised that SWA doesn't allow the use of autobrakes, if that is the case. I would think that autobrakes are essential for SWA if they are going to continue to operate into MDW and other airports in the upper Midwest and in the Northeast corridor. The autobrakes on the 744 that I fly are essential to our operation and significantly raise the margin of safety at short runways around the world. Autobrakes not only aid the stopping effort, but also aid significantly in directional control during crosswind landings. They are very valuable during a dark, stormy night at JFK landing 4R or 22L, with a heavy airplane, for example. Because the autobrakes meter fluid evenly to the brakes, it helps resolve, rather than cause, directional control problems both in slippery runway and crosswind situations.

[Astra driver]

Just out of curiosity I ran the Landing distance numbers on the computer program I use for the Gulfstream II that I fly. The factored wet runway distances came out as follows:

Runway 31C = 5,938ft (5,826 available)
Runway 13C = 5,123ft (6,060 available)
Runway 4R = 5,123ft (5,928 available)

Obviously the numbers for a boeing 737 would be different but it is interesting to see the effect that a "light" tailwind component vs a light headwind component can have on the distances. (815ft in this case)

[just.n.av8r]

RRAAMJET posted:

"Unbelievable comment here in Dallas from a member of SWA's Go-team - 'We had no fatalities on the plane, so that keeps our record intact'."

I agree, that is an unbeleivable comment. I have been unable to locate the source of that quote. Can you provide a link or at least tell us where you heard it?

Thanks.

Justin

[hmc]

As a layman I would like to know why something that seems as helpfull as auto-break would not be used.

Having flown into Midway I can say it was never one of my favorites, I always felt like I had to lift my feet on approach.

[just.n.av8r]

rr AA mjet

I see you post from TX. Sounds like you've got a heart on for your local airline:

I have to say, in persuit of cheaper airport operating costs, SWA does rather push the envelope in terms of the 'secondary' fields they prefer to operate from:

Islip, Long Island (v. short)
Orange County (ditto)
Midway (ditto)
Houston Hobby (short)


Take a look at who else operates large jets at these airports. Obviously Southwest and the FAA are not the only outfits that don't consider it pushing the envelope.

In addition, there seems to be a 'hurry, hurry' air to their ops, eg landing at ELP with large tailwinds to roll right up to the gate. Nothing illegal, but just pushing the envelope, it seems to me.

How "large" was the tailwind you observed on that 12020ft runway?

This was a tragic accident. Far be it from you or I to place blame anywhere with what little we know from the media, rumor websites, and preliminary statements. But I am inclined to beleive that this was not the result of corporate culture.

If you have a beef with Southwest because they are outperforming your airline or dragging down your pay I feel for you but your posts are beginning to lack credibility. Again I ask where you heard the earlier quote from an SWA representative regarding their "intact record".

Justin

[TR4A]

O'Hare (KORD) drives which runway is being used for Midway (KMDW). Aircraft were requesting to land on RWY 13C (headwind) and were told that only RWY 31C (tailwind, snow) was available.

Southwest currently uses RTO autobrakes. Autobrakes for landing is being added.

[patrickal]

CNBC was reporting tonight that preliminary FDR readings indicated that the touchdown was normal, but the plane accelerated after touchdown. If this is true, it would seem to indicated some problem with thrust reverers, or the crews ability to deploy them (yet still throttle up). I have not seen any other report that confirms this. It was on a bottom screen crawl.

[Shore Guy]

No experience on the later generation 737’s …..A couple of questions.

Another forum suggests that the winglet 737’s are relative “floaters” …..Is this true?

My guess is that they had Engine A/I on and probably Wing A/I on….how much does that kick up the idle on these motors?

[Rollingthunder]

I observe they're talking about EMAS (Engineered Material Arresting System) again. Only a few airports in the US are using it currently. Works very well from what I've seen.

[XTRAHOLD]

It will be wise to wait and see what the flight crew has to report first; all this speculation about if they did or did not use the autobrakes, automatic speed break deployment, max reverse thrust, etc is all interesting but unverified till they tell their side of the story. The DFDR that is installed on the -700 (B737NG) aircraft will give the investigators an incredibly accurate picture of what happened during the approach, flare, touchdown and rollout. There will be no way to hide the facts from the NTSB nor Boeing with the technology they have in that aircraft. It interests me much more the runway condition reports of the airport authority. I have had more than once the surprise of finding out after touchdown that the braking action report we based our decision to land upon was either too old or just simply false or wildly optimistic. When operating jets into an airport with these incredibly short runways, coeffiecient of friction reports should be available for all of them, I don't know if they do that at Midway? I simpathize with the flight crew as they must be going through some incredibly hard times now that the news is out about the passing of the little boy in the car. Aircraft commanders are high tech risk managers and have to continuously assess the safety of the operation at hand, many times with incomplete information and under extreme commercial pressures to complete the flight. Let us give these guys the benefit of the doubt till all the information is out. When I dead-head home, I always use SW; they are a great airline to fly on, their pilots are good and professional and I am pretty sure that it will turn out to be the commercial pressures to keep that airport open for business under those extreme wether conditions a major causal factor in the accident.

[repulo]

Shore Guy,

here some answers to your questions:

when my company introduced the NG with winglets we did see more long landings. They reduced significantly when the transition had been completed and awereness of the fact got more common. Basicaly, it´s a question of how well you fly Vref when close to the RWY.

Wing anti ice does not effect N1, just changes the stick shaker logic. Vref stays the same.

There are three idles on the NG:

ground
flight
approach

approach idle is selected with either engine anti ice on or flaps in landing config, so the idle N1 during the flare should be the same regardless off engine anti ice, since usually you land with landing flaps.

[amos2]

Let's not "Gild the Lilly" here Fella's...

they "blew it"...

you know it, I know it...

they're out of a job, and so they should be!!

:mad: :mad:

[just.n.av8r]

Not sure why pilots claim more float with winglets. Winglets actually reduce apparent ground effect because they already elimnate some of the spanwise flow creating the vortices. My experience is the NG's land firmer with less float if you fly your Vref. The trick is the Vref is much slower for the same weight so you need to pay attention to energy management to fly a proper approach.

[ATPMBA]

They will close the airport. Just like KDCA did about two weeks after thr Air Florida accident. We had to take the HS-125-700 over to Dulles to pick up the big boys. Of course after a month or so everything was back to normal.

[stagger]

This is not the first time a Southwest 737 has overrun a 6000ft rumway...

Excessive airspeed and flight path angle caused Southwest Airlines B-737 runway overrun in Burbank, California, NTSB says (http://www.ntsb.gov/Pressrel/2002/020626a.htm)

[captplaystation]

XTRAHOLD, couldn't agree more,been there ,done that;B/A reported good, in actuality nil, wind reported calm FMC shows 10kts tail ,because landing R/W is ATC or noise-abatement preferred. amos 2, I have reported your outrageous post & hope the mods will have the good sense to do for you what you are obviously incapable of achieving on your own,ie demonstrating a modicum of respect for another crew who may for all you know be completely blameless.

[Old Coder]

Just.n.av8r

Not sure why pilots claim more float with winglets. Winglets actually reduce apparent ground effect because they already elimnate some of the spanwise flow creating the vortices.

That's just the point though, isn't it? Something of a generalisation, but winglets help to reduce induced drag (by partially unwinding the tip vortices). Induced drag increases with angle of attack so would be [relatively] high during the float after flare - winglets will reduce the drag, so all factors being equal the float will be longer. Hope that made sense!

oc

[coco-nuts]

I hope for the pilots sake that when the boxes are opened, 1)they flew the numbers, 2) touched down on the 1000ft mark and 3) did all the things that Boeing recommends be done for a contaminated runway landing otherwise i fear they will be handing in their licenses.
This is strike two for the company under preetty much the same circumstances within a couple of years. A trend maybe?

RIP to the litte one.

coco

[Agent Mulder]

Low cost airline.

Low cost culture.

What cost Life??

[captplaystation]

With the greatest of respect,that is bollocks! Do you seriously think the greedy sh*ts in charge at any of the legacy carriers are any more caring,when it comes to the effect on their crew & customers,of cost cutting, than the US or European lo-co's? I really don't think so.This accident has little to do with lo-co, but perhaps a lot to do with the culture of corporate greed that pervades every aspect of our life on this wonderful planet of ours.

[the_hawk]

When an airline has 3 accidents with 1 casualty in 35 years of service - and even if all 3 are in the last 5 years - then it takes much (self) confidence to be sure it's because of lo-co airline and low-cost culture. Pure coincidence maybe?

[XTRAHOLD]

That is the problem with PPRUNE forums, it went from being a great cyberspace for intelligent discussions and exchange of ideas amongst professional pilots to a public bulletin board for people like amos2, stagger, agent mulder and the odd reporter snooping for a story. You people have no idea what you are talking about and show no respect to the fliers nor uderstanding for the multitude of factors that cause an accident like this. [B]

[Avman]

There's absolute rubbish being said in some of the above postings. I have the utmost respect for, and confidence in, Southwest and will not hesitate to continue flying with them.

[smokey762]

I fly the NG 737 and it is a bit slicker than aircraft without winglets. It's important to maintain prescribed approach speed and to establish the proper landing attitude. An over flare will cause float particularly if you are carrying excess speed. This seems to be more prevalent in aircraft with winglets but probably is due more to the efficiency of the wing itself which was completely redesigned for th 700/800 aircraft.

[just.n.av8r]

Old Coder,

Ground effect is an increase in effetcive lift due to the negation of wingtip vortices by the ground. It reduces drag and requires less thrust for the same airspeed/glidepath. When you have winglets this effect is less noticeable since your parasite drag is already reduced at the wingtips.

If you don't get it google it, I'm sure there are some rocket scientists that can due a better job than me explaining it. I just fly em.

[captplaystation]

Sometimes I wonder if everyone's account on PPRuNe shouldn't be cancelled,and proof of some professional involvement in the aviation industry become a pre-requisite to participation;I'm not saying I or any of us "professionals" are incapable of speaking absolute tosh,but it would hopefully reduce the number of moronic or politically motivated comments this & similar threads attract.In particular,any problem,or rumour/hint of a problem with a lo-co seems to invariably attract copious quantities of hysterical baying for blood from the usual sources,whilst conveniently ignoring the sheer number of sectors safely flown each & every day.I am glad I am not alone in getting a teensy-weensy bit fed up of it." PROFESSIONAL" (attitude as well as status) PILOTS rumours & news is fine by me,the rest sucks.

[smokey762]

Before we judge these guys shouldn't we at least wait for the facts to come out. This is a real tradgedy. A little boy was killed and several people were seriously injured. I would think all of us in the aviation industry owe these folks, their families, and the aircrew a thorough and fair investigation. Speculation, rumor and innuendo only serve to confuse the issue. There are many questions which are currently unanswered, but which will most certainly be answered by the NTSB in the coming days and weeks. Until then, I would submit that asking questions is fair game. Making conclusions, on the other hand may just demonstrate your own ignorance.

[Continuous Ignition]

No link but this is what's being reported in the news.

NTSB spokeswoman at the afternoon press conference said the touchdown airspeed was 124 kts. The wind 090/10.

98 Pax and no info on cargo and bags.

And for those of you who say the cowboy culture is alive and well couldn't be further from the truth.

I know that Flight Ops and Management went through a top to bottom review of the operation and unstabilized approaches were the focal point.

DFDAU Cards have been pulled for a long time now for reading and the results are investigated for ways to make the operation more effeicent and find irregularties in aircraft operations.

Sure these guys ask for shortcuts enroute/taxi kinda fast while trying to expedite the process of moving people. But at the same time, these guys aren't PAID by the BLOCK HOUR and the inefficiency this can create.

Pay is calculated by the trip. Its a formula that they came up with years ago using a set rule for a set city pair or something to that effect.

This encourages them to be efficient. But knowing they are watched via various modes (real-time engine trend ACARS reports and DFDAU readouts) will keep the cowboy culture in check. No one wants to be terminated from one of the last best commercial aviation gigs around

Have you looked at how much these guys are paid vs. counterparts at other carriers operating similar equiptment?

Also worth noting, this was the first flight of the day for the front end crew. So they should have been well rested and alert.

[SaturnV]

From the New York Times

The plane ... landed with a 13-mile-an-hour tail wind, making its speed over the ground - 124 knots, or 142 m.p.h. - slightly faster than normal, Ellen Engleman Conners, a member of the National Transportation Safety Board, said...... It hit the fence at 40 knots, or 46 m.p.h., and then hit two cars.

Despite the fact that heavy snow was falling at the time, braking was fair on most of the 6,522-foot runway but poor near the end, Ms. Engleman Conners said. "We cannot tell you the specific touchdown point."

The official briefed on the accident, who would not comment publicly because only top safety board officials are allowed to speak for attribution, said, "The first section of the runway had the best braking, and the last section had the worst."

A spokeswoman for the Chicago Aviation Department, Wendy Abrams, said a friction tester was sent down the runway about 20 minutes before the plane, Southwest Flight 1248, landed, and again right after it touched down. Each time, she said, "Braking action on that runway was good."

[coco-nuts]

Speed was no problem then, the only question left for me would be where the touchdown point was. I hope it was within the first 1500feet.

[flynverted]

132 knots touchdown speed according to the Chicago Tribune:

Runway conditions at the time a Southwest Airlines jetliner touched down during a snowstorm Thursday night at Midway Airport were "fair" for most of the strip but "poor" toward the end, federal investigators disclosed this afternoon.

Now they are trying to determine why Flight 1248 from Baltimore-Washington International Airport ran off the end of the runway, crashed through a concrete barrier and fence and smashed into vehicles on Central Avenue.

A 6-year-old boy riding in one car was killed. At least 10 other people—eight on the ground and two on the plane—were injured. Midway was shut down immediately after the accident, stranding some 600 travelers overnight. The airport reopened at 6 a.m. today.

Investigators hope to complete their site review and move the airliner from the street to an airport hangar Saturday, said Ellen Engleman Conners, a board member of the National Transportation Safety Board who is leading the inquiry.

Speaking at a late afternoon news conference, she detailed the sequence of events leading to the crash.

"The airplane had been in a normal hold position. The approach was normal with normal conversations. The crew did not mention problems with the airplane," she said.

"Air traffic control reported runway braking to be fair on most of the runway and poor at the end. Touchdown was normal. There was a slight bounce. There was a 7- to 8-knot tailwind. There was 32 seconds from touchdown until the aircraft hit the fence."

"Excellent" and "pristine" data has been recovered from the Boeing 737-700's flight data and cockpit voice recorders, Engleman Conners said.

Among other things, data showed the plane was going 132 knots, or 152 m.p.h., when it touched down at 7:14 p.m. Thursday on Midway's Runway 31 Center. It was traveling about 40 knots, or 46 m.p.h., when it went through the fence on the northwest corner of the airport.


http://www.stamfordadvocate.com/chi-051209flight1248,0,1719542.story?coll=stam-top-headlines

[Old Coder]

Just.n.av8r
No rocket scientists seem forthcoming, so I'll have one last go...
Ground effect is an increase in effetcive lift due to the negation of wingtip vortices by the ground.
Rather an effective increase in L/D ratio and, since the lift is constant (= weight) in the float, this implies a reduction in drag.
It reduces drag and requires less thrust for the same airspeed/glidepath. When you have winglets this effect is less noticeable since your parasite drag is already reduced at the wingtips.
Parasite (or profile) drag is actually increased slightly by the winglets -- it is the induced drag that is reduced. Whatever, as someone else said earlier, the wing on the -700 is "new"; the guys at Boeing will have optimised it for presence of winglets. The upshot is that, all other things being equal,the overall reduction in drag will make it float further.
But I don't fly 'em, so what would I know ;)

[Flyingphil]

Hey Guys,

my condolences to the victims!

Just my 3 Thoughts about the situation:
1. After the tragic crash of AA587 in 2001 the NTSB figured out that the Training-Standards and operational Procedures of American did not comply with the Standards/Procedures set by Airbus (Which finally let to the tragic "Pilot-Action" causing the accident).

2. Is is possible that also other Operators' have inefficient procedures or did they learn something out of AA587, meaning did they check operators procedures after they figured out their mistake causing the death of over 270 people?
A "No-Autobrake"-Policy would fit into such a picture.

3. Has anyone also information about the flightcrew?
I remember reading some reports of accidents in which the low level of experience was one(the main?) reason, e.g. the MD11 crashed @EWR in 1997.
Cpt had just 1000Fhrs on the 11, 3XX as PIC, while the F/O hat accumulated just about 100Fhr total on MD11, so I hope the guys in question have been more experienced otherwise they and WN get blamed for their Training :(


Finally, in german Online-Newspapers an NTSB-Guy is quoted stating that the Touchdown was @about 750ft, so definately out of the Touchdown-Zone.
This combined with poor WX-Conditions would definately cause a RWY-Overrun if I am not totally wrong with my calculations, even in good WX-Condition this would cause a critical Situation (At least with no Autobrake if this is true!)

Has anyone information concerning this?

BRegards Phil

[captplaystation]

Sounds like three-quarters of the way into the touchdown-zone to me then.

[Mad (Flt) Scientist]

Just.n.av8r
No rocket scientists seem forthcoming, so I'll have one last go...

Ground effect is an increase in effetcive lift due to the negation of wingtip vortices by the ground.

Rather an effective increase in L/D ratio and, since the lift is constant (= weight) in the float, this implies a reduction in drag.

It reduces drag and requires less thrust for the same airspeed/glidepath. When you have winglets this effect is less noticeable since your parasite drag is already reduced at the wingtips.

Parasite (or profile) drag is actually increased slightly by the winglets -- it is the induced drag that is reduced. Whatever, as someone else said earlier, the wing on the -700 is "new"; the guys at Boeing will have optimised it for presence of winglets. The upshot is that, all other things being equal,the overall reduction in drag will make it float further.
But I don't fly 'em, so what would I know

Don't know much about rockets, but ....

Usually winglet design is quite closely tailored to specific design points. The two biggies being either to reduce cruise drag for range/SAR type purposes, or to improve best L/D or CLmax for the lift-off/takeoff cases. It'd be quite unusual to have the landing case as a major design goal, since the thing winglets tend to be best at - improving L/D - is almost exactly what you don't want on approach.

All that taken into account, I suspect the winglets on this (and many other) aircraft are not very (or at all) efficient during the flare; it's entirely possible that they are increasing drag over an "unwingleted type" under similar conditions.

More importantly, the field performance demonstration will have been conducted for the specific configuration, and from that will have been derived the "air distance" portion of the landing distance data. That will include, necessarily, any tendency to float that may or may not exist on a type (from whatever cause) and, if found necessary, design changes would have been made or recommended procedures amended.

So whether a type has winglets or not, whether it flares differently or not, should all be already accounted for.

[smokey762]

This touchdown would be very normal for MDW, particularly with the wx /runway conditions. If indeed this is true and the NTSB quoted touchdown speed was, in fact 124knots and the aircraft systems were operating normally, something is not adding up? Airport authority people are saying the runway condition was good 20 minutes prior and immediately after, but that doesn't seem to jive with pilot reports which called braking fair and poor at the departure end. Wonder how long it had been since runway was plowed? I've seen some reports from passengers who say that after evacuating the aircraft they couldn't discern the difference between the field and the runway. Weather reports and statements from people on the scene say snow was falling at about two inches per hour. Wonder if it was wet or dry snow. Could the data the crew used have been erroneous? If the runway condition was ,in fact, worse than reported in the ATIS, would that not make the landing data erroneous? It would be interesting to know how long the aircraft was at 40knots prior to exiting the runway. Might tell us something about how slick the departure end actually was.

[vapilot2004]

After the tragic crash of AA587 in 2001 the NTSB figured out that the Training-Standards and operational Procedures of American did not comply with the Standards/Procedures set by Airbus

American Airlines SOPs would have been a l-i-t-t-l-e different had they known more about the unusual and problematic rudder control system and the relative strength of the composite tail. It has been shown that Airbus' own FCOM's on this model is contradictory when it comes to left/right rudder movements.

Pilot's unions and professional groups here in the US representing those flying the 110 A300's wanted more NTSB investigation into the computerized control system, which according to testimony of numerous maintenance technicians and engineers , was problematic on these aircraft.

We all know how government safety boards are loathe to blame the equipment. It's kind of like when a Navy ship is lost or damaged, the Captain will always be at fault and the loss of his command is nearly 100% certain.

[Mr Hankey]

Pilot's unions and professional groups here in the US representing those flying the 110 A300's wanted more NTSB investigation into the computerized control system, which according to testimony of numerous maintenance technicians and engineers , was problematic on these aircraft.

Much like pilots should want fuel tanks blowing up and rudder hardovers should be investigate in certain Boeings, eh?!

[vapilot2004]

.Much like pilots should want fuel tanks blowing up and rudder hardovers should be investigate in certain Boeings, eh?!

Absolutely ! Multiple pilot's groups did voice concerns over the 737 rudder design in the early days. I think that the 747 center fuel tank is a bad example. It is the proverbial 'another story'.

I think we all agree, that if there is a potentially life-threatening flaw within any technology, the flaw must be fixed or mitigated or the technology should be abandoned and a lesson learned.

As we know, fixes are achieved through revised operational guidelines or refits, or most often a combination of both. To achieve the highest degree of safety, the foreknowledge of design, manufacture and/or implementation shortcomings must be exported. Sharing this critical data with our partners is paramount if we are to prevent an otherwise avoidable tragedy.

You see, it is the minds of engineers, the hands of highly skilled craftsmen, the cunning of financiers all working for the visionaries who founded enterprises that build what we fly today. They may not be 100 % perfect, but are as perfect as they can be within the current system. The problem comes when ultimate control over safety disclosures is taken from our creative team - by the most unqualified branch of the enterprise for this task.

The legal and politically-motivated executives are the rotten apples of the bunch. Misguided fear and blinding greed has spoilt them - leading them to some :mad: poor choices, choices that some of which eventually will bring consequences, sometimes deadly consequences as history shows.

I think our collective fates would be best served by taking the reins of corporate aviation safety away from the Harvard MBA's and corporate attorneys at the top and giving them over to those who can best serve our pursuit of safety - the INSA Lyon, UC Davis, Oxford at Cambridge or Edinburgh University-trained engineers.

The previously mentioned misguided corporate governance happens all around - A or B.

I may be naive, but Integrity always trumps money and politics, doesn't it ?

[Airbubba]

A throttle not in full idle after a gusty (or gutsy) approach? Ice on the microswitches preventing reverse in one of the engines? I've had both of those at times in winter conditions...

Or possibly no below 5 feet RA signal?
______________________________________


December 10, 2005

Reverse Thrusters Eyed in Midway Accident

By THE ASSOCIATED PRESS
Filed at 10:06 p.m. ET

CHICAGO (AP) -- The reverse thrusters that should have slowed a Southwest Airlines jetliner before it slid off a runway at Midway Airport and into the street didn't immediately kick in when the pilots tried to deploy them, federal investigators said Saturday after interviewing the crew.

How much of a role that braking equipment played in Thursday's deadly accident wasn't immediately clear, though, and the investigation is continuing.

The plane's flight attendants told investigators that the Boeing 737 didn't appear to slow after it touched down at Midway in a snowstorm Thursday, said Robert Benzon, the National Transportation Safety Board's investigator in charge.

''They all said it was a smooth landing but they could sense a lack of deceleration,'' Benzon said.

He said the pilots told investigators they began applying the brakes manually as soon as they noticed that the plane wasn't slowing properly...

http://www.nytimes.com/aponline/national/AP-Midway-Accident.html

[6000PIC]

I`m going to ask a silly question.
Why is it that in the Northern Hemisphere , ( hello WINTER ! )we don`t have more efficient systems to keep runways contaminant - free even during the worst of snowstorms ?
Or why even bother the approach at all ? Commercial pressure ?

[Rananim]

With flaps 40,max manual braking,and zero tailwind you need about 4200 feet to stop.Thats at 112,000 lbs with good braking action.But with poor braking action,it shoots up to around 6700,well outside Midway.You lose anything from 70 to 190 feet for each knot of tailwind,depending on braking action.
Runway condition reports arent cast in stone;they're a good indicator but the roll-out coefficient may well not be as good as the touchdown or mid-point.Pilot reports of runway condition are usually a more reliable source.

Avoiding overruns in this kind of weather is a real test of judgement;if at any stage in the deliberation process you're not convinced that sufficient margins exist,divert.Its that simple.If it can happen to SWA,it can happen to anyone.

[Ignition Override]

Just. n . av8r:

You might be aware of this.

Southwest pilots are the highest-paid B-737 pilots in the US, possibly in the western hemisphere (no pay cuts, so far). Check huge pay cuts at most US majors right now. And Southwest is not a low-cost airline (and has been heavily-unionized for many years), if one looks at certain hourly labor costs. But they are an efficient, productive company.

As for using assymetric reverse on slippery runways, I have never heard of this being recommended in a jet.
A different problem which is never discussed involves using inter-mixed engines. With equal, vertical positions on both thrust reverser levers, one Pratt & Whitney JT8-D engine can give you 1.0 EPR but the OTHER engine can jump up to about 1.7 or 1.8!
Unless you can land with no tailwind on a slippery runway and know when the latest braking action report was made-by a swept-wing transport jet, and what is the latest MU value, you had better plan on diverting to another airport with longer runways (also, when was the last time they were plowed, and were chemicals sprayed, or runways just sanded?). Even a gust of wind at 30 feet AGL can push you a good bit above the glideslope and create a long touchdown point.

Flying Phil:

Were there not unexplained incidents involving A-310/300 rudder control systems at former eastern German ("DDR") airline Interflug, and also with Air France, or another French airline? I read somewhere on Pprune months ago that American Airlines was not notified about these alleged incidents, at least until after the crash of flight 587 in Long Island. Did the NTSB (safety board) learn about it during the investigation?

Incidents/accidents have involved foreign aircraft in the past and the US FAA keeps the news very quiet (i.e. ATR-42 aileron "snatch", the extra sensitivity of leading-edge icing on a Canadian F-28), until bloody passenger bodies :ouch: are removed from the wreckage, i.e. from the ATR in Roselawn, Indiana, and from the USAir F-28 at LaGuardia (LGA). Read up on creation of the FIRST rest periods for US standby/reserve crewmembers (what previous, designated rest existed, except for 24 hours each 7 days?) after the tragedy in Little Rock (LIT).

Having only dead, mutilated crewmembers is never any big deal. These have no real media value, and therefore do not pose a public relations danger to a huge, politicized agency, whose top bureaucrats are appointed by whoever lives in the White House.

[coco-nuts]

750ft touch down point? ok slightly less than the 1000 footer but this should have worked in the crews favour and not against it!!
I cannot see the crew getting caned for this.

cheers
coco

[Flyingphil]

@Ignition Override

So you have different information than me.
It is correct, there was an Incident in Moscow by Interflug just months before the Wall of Berlin was broken:confused:
I don't see any parallel to AA since the final outcome of that Incident was that the Autopilot was wrongly programmed by the crew.

I don't know about a similar incident with AF, what I know for sure is that the crash of a Tarom-A310 in 1992(?) was also related to the same basic problem.

My statement is based on the fact that I was able to speak with an Acc-Rep of Airbus who was temporarely Member of the AA587-Invest-Group.

He clearly told me that the Procedures used by AA were updatet several years ago and that AA and the FAA were informed about that by a Bulletin.
Conclusion:
1. Mistake wiz tragic consequence:
AA did not change the procedures

2. The FAA did not check the Procedures of AA and so could not require AA to do so!

I don't wanna discuss on AA with you, the only think I would like to say is that
the FAA at least one time with dramatic consequences forgot to monitor the Airlines and I was thinking about that fact again since -I assume everyone agree's- this might has happened for a second time if it is true that the WN-Operations exclude Autobraking - even in poor WX-Condition

Have a nice Sunday

[smokey762]

Don't know about the AA situation with the Airbus, but it would seem that comparing that situation you described to SWA and autobrakes is like comparing apples to oranges.

Does the FAA mandate the use of autobrakes for all carriers in any meteorological conditions? Does Boeing refuse to sell aircraft to companies with the knowledge the company will not use the autobraking system? Is the FAA required to approve a 121 Carrier's FOM procedures?

The -700 has an outstanding FDR which taken in conjuction with thw CVR info will allow the NTSB to accurately determine exactly when braking commenced after touchdown and if braking was a factor. If so, they will make recommendations to the FAA.

If it is determined the use of autobrakes would have precluded this accident or might preclude one in the future, you can bet the FAA will mandate the use of autobrakes in inclement wx with no MEL relief.

[satpak77]

Guys

The approach plate below states "landing length" available for 31-C is 5826 feet.

http://myairplane.com/databases/approach/pdfs/00081ILD31C.PDF

It also says RVR 4000. The press claims the viz was 1/4 mile when they landed. Would this not be below the approach viz?

With a tailwind component of 10 knots, plus fair to poor braking (how many pilots really report NIL, knowing the runway may be closed after that...), etc etc, and I think the deck was stacked against the crew that night.

The thurst reversers are being looked at, but the NTSB press conference stated when they landed, there was a slight bounce. Could this delay the deployment of the TR's?

I wonder what the outcome would have been if Auto-Braking was used by SWA.

[satpak77]

http://www.chicagotribune.com/news/local/chi-0512110438dec11,1,5398944.story?coll=chi-news-hed


--------------------------------------------------------------------------------

Stuck jet switch cited in accident
Pilots' efforts to stop plane were delayed, investigators say

By Jon Hilkevitch, Tribune transportation reporter. Tribune staff reporters Brendan McCarthy, Lisa Fleisher, Jonathon E. Briggs and Dave Wischnowsky contributed to this report
Published December 11, 2005


Vital seconds were lost while trying to bring a Southwest Airlines plane to a halt on a slick runway at Midway Airport because a balky switch delayed deployment of devices that reverse the thrust of the jet's powerful engines, investigators said Saturday.

In the first account by the pilots of the Thursday night accident, the captain of Southwest Flight 1248 told investigators the flight from Baltimore was "completely normal" until he landed the plane at the Southwest Side airport.

A control on the throttle to activate the twin-engine plane's thrust reversers would not slide into place, the 59-year-old veteran pilot told investigators from the National Transportation Safety Board.

At that point, the first officer in the right seat of the cockpit leaned over and was able to deploy the thrust reversers while the captain applied full braking power to try stopping the plane.

The thrust reversers redirect engine power forward to slow the aircraft, and work in conjunction with automatic brakes that investigators said activated immediately upon landing the 737-700. Flaps on the wings, called spoilers, also help kill speed. Investigators say the spoilers were working.

When the captain saw that they were running out of runway, he also used his brake pedals to provide extra stopping power, said Robert Benzon, the investigator in charge.

The captain told safety board investigators he was concerned about the weather in Chicago, but was unaware of the "unique weather phenomenon" that was occurring around them. National Weather Service forecasters told the safety board that an "enhanced snowbank" was coming into the Chicago area at the same time the plane was flying toward the Midwest.

Officials are not releasing the pilots' names.

Visibility was about two-thirds the length of the runway at Midway when Flight 1248 descended through low-hanging clouds, and the flashing lights of the airfield below became visible in the blowing snow, according to new data received Saturday.

Working backward from Thursday night, when the aircraft smashed through an airfield barrier and rammed vehicles on Central Avenue, investigators have sifted through data from the cockpit and flight recorders, air-traffic radar and weather advisories to create a second-by-second chronology.

One major unanswered question is where the plane, gaining speed due to a tailwind, touched down in the landing zone on the first third of the 6,522-foot runway.

The plane needed to land within about the first 2,170 feet of the runway to stop on the snow-slicked surface, which was rated "fair" to "poor" for aircraft-braking ability by the pilot who landed several minutes in front of Flight 1248, transportation officials said.

Investigators still want to know whether the plane crossed the runway threshold at the correct altitude and speed--or if it was too high and too fast--and how much those factors reduced the pilots' ability to bring the aircraft to a safe stop.

Joshua Woods, 6, was killed, and his parents, Leroy and Lisa, and two brothers were injured when their car was crushed by the plane. Their attorney Ronald Stearney said Leroy Woods was released Saturday from Advocate Christ Medical Center in Oak Lawn. He said Leroy Woods suffered one fracture at the back of his skull and four under his right eye.

Steven Peters, Joshua Woods' uncle, said the family's main focus is now on preparing to bury Joshua. Funeral arrangements are pending.

Saturday's snowfall and weather conditions, although drastically less threatening than Thursday's conditions, contributed to many airline delays and cancellations at both Chicago airports.

At Midway, Southwest Airlines had canceled all flights by about 6 p.m. Saturday, said company spokeswoman Linda Rutherford. She said Thursday's crash did not factor into the company's decision.

"For our type of operations, the airport went below minimums [in visibility]," Rutherford said. "On Thursday ... it was not below our minimum visibility."

Rich Brumer, a meteorologist in the National Weather Service office in Romeoville, said Saturday's conditions were more conducive to airplane travel.

"The temperature is about the same, but the snowfall is much less," Brumer said. "The winds are a little stronger, but visibility and the ceiling is much better."

As of 7 p.m. Saturday, the Chicago Department of Aviation said about 60 Midway flights had been canceled and at least seven flights diverted elsewhere because of poor weather conditions and only one operable runway.

On average, Midway has about 300 departures a day.

At O'Hare, United Airlines and American Airlines reported delays of up to 90 minutes and at least six cancellations.

Meanwhile, the Federal Aviation Administration worked Saturday to replace an aircraft-guidance antenna that was knocked out during the crash. The equipment, which guides planes down a glide path to the airport, is needed before the runway on which the accident occurred, 31 Center, can be reopened. The runway was expected to be back in service Sunday.

Mayor Richard Daley said Saturday that he did not want to examine the idea of expanding runway safety areas at Midway until the board completes its investigation.

"This airport has been very safe. Southwest Airlines has been a safe company," Daley said at a news conference.

Daley sought to reassure residents living around the airport that the area is safe.

"They've lived there for so many years and there's not been many accidents," he said. "More people are killed on expressways, so would we shut down expressways?"

----------

[email protected]





Copyright © 2005, Chicago Tribune

[Willie Everlearn]

Does SWA include TEM in their indoc and recurrent training???

It seems to me that this SWA crew was probably just as intelligent as most Second Guessers on this forum. With that in mind, I wonder:

1.) Does SWA use the 700's Auto Brake System for landings as an SOP?

2.) Does SWA have a policy regarding the use of ABS when landing on contaminated runways?

I understand the ABS isn't much help on a dirty runway if you don't plant it on the numbers.

3.) What's the deal with no thrust reverser deployment? News articles suggest the crew had difficulty using it on landing. I conclude they used it at some point in the landing roll. Yet we haven't we seen a single photo with both thrust reversers deployed?

Wouldn't the crew have used all available braking to get it stopped? (My answer is yes on that one BTW) It's difficult to tell from the photos (inconclusive evidence by any means) but it looks to me like there are no spoilers deployed, no thrust reversers deployed and you'd think these componenets would be deployed in light of the fact they were headed for an 'off airport' intersection.

(were they stowed when everything came to rest?)

Anyway, I'm off to look at an AOM.

My deepest sympathy to young family who's car was crushed and their loss.
:(

[RRAAMJET]

Hi Just'n - sorry I didn't get back to you earlier, I was on a trip. No beef against SWA, just it seems to me that they needlessly push the envelope for no reason. If you're landing at ELP, 4000 ft asl in warm conditions with a 12kt tailwind component on 22, it just seems to me that that's just not as safe as it could be which has always been my mantra. Just because you can doesn't mean you should. Ditto with tailwind onto short rwy at night in snow.

If you are the #1 airline in any given market, there is simply no need to push it; just sit back and let the opposition stew in their own mess. I don't understand why SWA crews still rush everywhere - they're #1, no need to risk anything. Commercial pressures should certainly no longer be a factor, as this can lead to 'press-on-itis'.

The quote from the SWA official came from a CH5 reporter outside SWA headquarters here in DAL, who said that he had just spoke to a member of the assembling go-team who said the comment. Give CH5 a call and ask for their archival report.

By the way, folks, I may be wrong, but in the FAA isn't there no credit for reversers in calculating stopping distances?

Also, have to concur with previous about assym. rev. use on slick surface - can actually increase instability in directional control due to adverse component of the thrust vector...

[BOAC]

WE - but it looks to me like there are no spoilers deployed, no thrust reversers deployed - I do not wish to add any conjecture to this sad accident, except to remind all (as you SHOULD know from your profile) that it is NORMAL procedure for pax evacuation to stow both the reversers and spoilers in preparation - as you correctly hinted, and I believe the same comments were made following the AF 340 over-run?

[arewenearlythereyet?]

Sadly, it is all too easy for someone to make up 'porkies' in their profile. It is precisely comments by the likes of Willie Everlearn that exposes those fakers or pretenders as to their real levels of experience. No thanks to the likes of Wille and quite a few others on this thread they have demeaned this forum.

Why can't those of you who have no understanding of the job go away and leave this forum to those of us who do. At least limit your posts to questions rather than pig ignorant statements and assumptions based on little or no experience except that gained from watching Discovery Wings. :rolleyes:

Thanks BOAC for being so polite but it is very infuriating when these threads are ruined for the majority by nerds who only like the computer equivalent of hearing their own voices. If you're going to speculate then at least make sure you do so from a position of experience otherwise you just come across as an 'anorak' pretender. :yuk:

[smokey762]

RRAMJET

From what I've seen in the last few years SWA has slowed down significantly. Look at their ontime performance today as opposed to the late 90s.





The NTSB will build a very accurate profile from the FDR. They should be able to determine the touchdown point within a few feet and whether or not the aircraft was on speed and on glidepath. From the profile they will generate a computer animation which, I'm sure, we'll all get a chance to view.

[TR4A]

ELP Rwy 22 12020'x150' Landing distance available 12020'

rrAAmjet (American Airlines pilot) said No beef against SWA, If you're landing at ELP, 4000 ft asl in warm conditions with a 12kt tailwind component on 22, it just seems to me that that's just not as safe as it could be which has always been my mantra. Just because you can doesn't mean you should. Ditto with tailwind onto short rwy at night in snow.

rrAAmjet there is a 10 kt tailwind maximum for landing in a B737. (15 kts for B737-200). Are accusing SWA of exceeding a AFM limit?

MDW's landing with a tailwind (31C) is dictated by ORD (O'Hare).

[dallas dude]

TR4A,

We were #2 holding short of RW03 behind a CAL 737 at KSAT several days ago watching a certain airline (many, many good pilot friends work there and I regularly j/s on them with absolute confidence) depart with a tower reported wind 210 at 13.

CAL was offered take off clearance and declined, prefering to request a departure on 21. We did the same.

AA is limited to 10 knots tailwind. Don't know about CAL or SWA.

Now, to the point. There are folks at EVERY airline that push limits and most of the time get away with it.

MDW is not a place for amateurs. I don't believe SWA pilots are (look at the requirements to even get an interview). However, as professionals we are increasingly "coerced" into making the present system work, despite its shortcomings.

MDW is a tough place to operate on a good day. It's absolutely tragic that the death of this little boy, despite the high skill level and competency of the flight crew, will not be enough to prevent a repeat some time in the future.

My condolencies to the boy's family and sympathy to the flight crew, who must live with this tragedy for the rest of their lives.

dd

[TR4A]

We were #2 holding short of RW03 behind a CAL 737 at KSAT several days ago watching a certain airline (many, many good pilot friends work there and I regularly j/s on them with absolute confidence) depart with a tower reported wind 210 at 13.Was it a -200? It can takeoff and land with 15 knots.

[ATPMBA]

Shoudn't SW be able to land W/O using thrust reversers?

I thought landing performance for a Part 25 certified A/C was based on NO Thrust reverse.

[RRAAMJET]

TR4A - No, no, no!YOU are the pilot in command. "...dictated...by ORD..." Absolutely not. It's the pilot in command's decision to accept the conditions, never to have them 'dictated' to him/her. The sooner some of the aviators here in the US put their collective feet down and lay down the law occasionally to the FAA, the better off we'll all be and the less the chances of this sort of thing happening. Too often I listen in amazement as pilots here allow the FAA to effectively take over control of their a/c - it's ridiculous. Divert, if necessary, but safety first.

Yes, I'm well aware of rwy alignment policies in the Chicago area - it doesn't mean it's correct - and I'm sure it will come heavily under scrutiny in this case.

And yes, I'm certain of the wind component at ELP....:rolleyes:

Smokey - I believe their on-time perf. tracking methods have changed in recent years...;)

ATPMBA - my point made above - you receive no credit for reversers operative/inoperative in landing distance calculations. I don't see that reversers failing to deploy would therefore become prime causal, more of a major distraction, if that's indeed the case.

[dallas dude]

TR4A,

It wasn't a -200 [CFM's] but that wasn't the point of my post.

We ALL do it from time to time to as a means to 'fix' the broken wheel, not just SWA.

The assumption from many non-SWA pilots is that "it's just a matter of time 'til SWA...".

Our [collective] inherent desire to assist in/ensure our individual airline's future needs to be balanced with the reality that we are all just one mistake away from the street-no pun intended.

There are likely some things we all see out on the line which, frankly, make most wonder what we're trying to achieve. Ultimately, the lawyers will leave the flight crews holding the can and that's a lesson we must carry on our shoulder straps each time we insert them in the buckle.

Cheers,dd.

[TR4A]

It's the pilot in command's decision to accept the conditions, never to have them 'dictated' to him/her. I agree, but they did they have the accurate conditions to make that decision? I sure hope that the FAA changes it's policies of not allowing other smaller airports changing the runway direction. It happens in Dallas, Chicago, San Jose, Oakland and many others.

There are likely some things we all see out on the line which, frankly, make most wonder what we're trying to achieve. Ultimately, the lawyers will leave the flight crews holding the can and that's a lesson we must carry on our shoulder straps each time we insert them in the buckle.Unfortunately true.

We all need to let the NTSB do their job. Too many on the Internet are quick to jump on Southwest.

Southwest has an excellent safety record.

[RRAAMJET]

DD, better-put than perhaps I could manage. Which brings me back to a point I made earlier: if you are already the undisputed top dog domestically, there is no need to push things. Protect your safety reputation at all costs.

[Ignition Override]

FlyingPhil: Grusse, I could be mistaken about flight 587, but was it not the flight number for the A-300 which departed JFK behind a large widebody aircraft (within a week of the 9/11 nightmare), and then the vertical stabilizer and an engine broke off? Many people suspect that a rudder control unit had a sever malfunction. But the FO was blamed for the overstress, although other problems with rudders had already happened with other A-300/310s?

The AA flight at Cali, Columbia had a different flight number. By the way, Honeywell reportedly had two different fixes in the database for the same identifier, Tulua, but this was not the primary cause.

Gleichfalls, schonen Montag.

[Willie Everlearn]

arewenearlythereyet?
Thanks for the advice.
But I'd say based on your comments, you're an idiot. You haven't the slightest idea about my qualifications OR experience!

A number of things fascinate me about this (and other) accidents that will undoubtedly follow the suggestion that we "learn from the mistakes of others for we won't have time to make them all ourselves". That's how it's done in this business in case you hadn't noticed. There's absolutely nothing to be gained by gloating or taking the "can't happen to me" high ground, for it surely can.

Perhaps you should go back to your 'beverage' and not bother speculating about who's got credibility with YOU and who doesn't. Try to take in the bigger picture and lighten up.

BOAC

I'd understand that under a normal reject where the aircraft remained on the pavement, spoilers and reversers would be stowed. Evacuation or NOT.
I haven't had an overrun experience but I do recommend to students under simulator training they keep the TRs deployed until a full stop. Now, depending upon the actual overrun, you may or may not get the TRs stowed.
(i.e. What if the engines ate up plenty of sod and shut themselves down? Not the case here, but...what if?).
Whatever. Not wishing to speculate, following questionable prose in the print media, I was merely sitting about on a pleasant Sunday afternoon wonder "if". The press are reporting a 'switch' in the reverse mechanism delayed TR deployment.
It could simply mean they were unable to get it quickly into reverse because of the reverse thrust interlock solenoids. We'll see.

I'm also confused about the SWA policy on the use of Auto Brake. (I have no idea what it is but some air carriers have a DO NOT USE policy. Are they one of those airlines?)
With auto brake selected for landing, why would the crew assist the auto braking by applying Manual brakes? The auto brakes I'm familiar with disengage when manual brakes are applied. So, I do find the sequence of events rather puzzling, don't you? One more point on auto brake. I've been lead to believe that auto braking is more effective and efficient than we humans. Have you heard that as well?

I also don't recall seeing in these photos slides deployed at 1R or the overwing exit doors removed over the RH wing even though we do know there was a PAX evac.

I guess these questions are somewhat premature, and since some find them annoying, I'll say no more.

dallas dude

very well said. Therefore, my curiosity about Threat and Error Management at Southwest.

[FIRESYSOK]

"Shoudn't SW be able to land W/O using thrust reversers?

I thought landing performance for a Part 25 certified A/C was based on NO Thrust reverse."


Ahh, yes! However, this was a contaminated runway! Factored landing distance does not account for runway clutter. You must use ACTUAL landing distance numbers for landing on a runway with equivalent contaminate. 1/4" wet snow, 1/2" dry, or whatever your runway of choice seems to be suffering from at the time!

Bye Bye!

[TR4A]

With auto brake selected for landing, why would the crew assist the auto braking by applying Manual brakes? The auto brakes I'm familiar with disengage when manual brakes are applied. So, I do find the sequence of events rather puzzling, don't you? One more point on auto brake. I've been lead to believe that auto braking is more effective and efficient than we humans. Have you heard that as well?
MAX autobrake setting is not like RTO. Maxium manual braking is greater than MAX autobrake.

[satpak77]

http://www.b737.org.uk/limitations.htm

"No tailwind component allowed on contaminated runways"

I think we may have some legal problems if this limitation applies to the 737-700

[TR4A]

This is posted on that site:
Note: Not all limitations given here are AFM

[satpak77]

true, I agree 100%

just putting that out there for discussion, maybe we have some 737-700 drivers in the audience

[TR4A]

I am a B737-700 driver. It is not a AFM limitation. Some airlines may have it as a company limitation, but they probably get to land into the wind all the time.

[satpak77]

roger that....any AFM guidance for landing on contaminated runways?

[Airbubba]

Some of these perfomance "limitations" get miraculously removed when you pay Boeing for the extra data. High altitude and increased tailwind are mentioned as options on web page cited above.

[satpak77]

TR4A- just saw your post on the other site....

thanks

[smokey762]

Satpak77

FOM states 10k max tailwind for landing with clutter exceeding 25% of the runway. Does not decrease until breaking action poor is reported, the limit then becomes 5k.

[019360]

In "Handling the Big Jets" Davies said in reference to landing on contaminated RWs, something along the lines of, "If you mess it up and go off the far end you'd say to yourself, if only I had those last 2 minutes over again. Well as you aproach the threshold you DO have that time so use it well and if there's any doubt, go around and divert or do it again".

I don't have it in front of me so I hope I haven't misquoted, but that's something we try and teach all our pilots. Unfortunately he wrote those so true words 30 plus years ago...before the current "new breed" of CEOs and Ops. Managers came onto the scene.Oh well...if you don't learn from history, then you will learn from history.

[Airbubba]

“Those who do not learn from history are doomed to repeat it.”

George Santayana
(1863-1952)

[RRAAMJET]

019360 - a book well known amongst those of us who have flown for Cathay, etc, but not well known in the US.

Still an authoritative script in many regards.

I feel terrible for the the families facing bleak Christmas's - victims, and particularly, crew. :sad:

[theflightline]

Hey Willie Everlearn,

"I haven't had an overrun experience but I do recommend to students under simulator training they keep the TRs deployed until a full stop. "

If you ever get out of the sim and try this in the snow you will find yourself blind (in whiteout conditions) at about 80 kts....... just thought you might like to know :)

[coco-nuts]

A friend who teaches on the 73 sims once told me and i hope i dont misquote him here that using reverser only on an 8000 foot runway will have the aeroplane happily overunning the end of the runway. The reverser being useless below 45 knots. Brakes must be applied whether auto or manual to stop the aircraft. Apply brakes too late and you will still run off!

cheers
coco

[skyguyz]

Amos2 post:

Let's not "Gild the Lilly" here Fella's...

they "blew it"...

you know it, I know it...

they're out of a job, and so they should be!!

Amos2 is reacting upon emotion without the slightest benefit of intellect.

This person is speculating worse than the talking heads on TV.

With this persons lack of judgement, would you want to have him as PIC?

[Astrosfan]

Not a professional pilot, not a journalist, just a frequent flyer, many times on WN, with a question arising from this incident.

Assuming that the flight crew on this particular flight became aware at some point that coming to a complete stop with whatever runway remaining was improbable, could they have applied full power and taken off to avoid the runway excursion? And if so, by what point on the runway during the course of the landing at the latest would this decision had to have been made?

Or, if you prefer, I would be happy with the discussion of a more theoretical example if you prefer not to speculate or comment on the specific cirucmstances of this incident since many of the facts remain undisclosed.

[4Greens]

Somewhat simplistic answer but for info:

You have the option of getting airborne again, depending on runway availability etc, until the point at which you select reverse thrust.

[Astrosfan]

I apologize for posting this thread separately as I intended to fit it in the "Southwest B737 Overrun @ Chcago MDW" thread. If the moderators want to place this post/response in that thread or somewhere else, that would be fine with me.

With that aside, I just wonder what options a pilot may have following landing other than to apply the thrust reversers, full braking, and spoilers if safely coming to a stop with some airport real estate left appears infeasible.

I assume most pilots would be highly unlikely to abandon a landing once on terra firma for a variety of reasons, but I am just curious as to what consideration is given to going full throttle and taking off again to get another shot at a safe landing, perhaps at a different airport with a much longer runway (and/or much better conditions).

Thanks for your answer, 4Greens. I understand why applying reverse thrust commits you to trying for a safe stop.

[Shore Guy]

Well, folks, the vultures (read attorneys) are already circling....

Here is my letter to US Federal District Court...



Chief Judge Michael B. Mukasey

United States District Court

Southern District of New York

Daniel Patrick Moynihan United States Courthouse

500 Pearl Street

New York, NY 10007





Judge Mukasey,



I am submitting the following for your consideration as I believe it falls under your venue.



The following press release was distributed by the firm Kreindler and Kreindler LLP (with offices in New York City) on Friday, December 9, 2005. This press release was distributed less than 24 hours after the accident involving Southwest Airlines at Chicago’s Midway airport on Thursday evening, Dec. 8, 2005.



Press Release
Source: Kreindler & Kreindler LLP

Fatal Landing of Southwest Airlines Flight at Midway Airport in Chicago Last Night is Similar to Previous Runway Overrun Accident Carrier Has Had
Friday December 9, 4:30 pm ET


May Be Indicative of Carrier-Specific Problem, Says Nation's Leading Aviation Law Firm



NEW YORK, Dec. 9 /PRNewswire/ -- The fatal landing of Southwest Airlines (SWA) Flight 1248 at Chicago's Midway Airport in a snowstorm last night is strikingly similar to at least one other runway overrun accident involving Southwest, and may be indicative of a carrier-wide operational problem, according to attorneys and pilots with the aviation law firm Kreindler & Kreindler LLP (http://www.kreindler.com). The previous incident occurred at Bob Hope Airport in Burbank, CA, on March 5, 2000, injuring several people on the ground.



"While the investigation is ongoing and the specific cause in the Midway accident is not yet determined, it was the direct responsibility of the Southwest flight crew to safely land the 737 aircraft or make the decision that a safe landing could not be accomplished," said Daniel O. Rose, a partner at Kreindler who is also a highly trained pilot. "The crew, as do all crews, had the option to either abort the approach or divert the plane and passengers safely to another airport. Does this suggest a pattern in SWA's flight operations?

"In the Burbank crash of a 737-300, injured parties successfully claimed that SWA fosters a culture of expediency, cost savings and an aggressive 'get the plane down' approach that, in combination, compromised passenger safety," said Mr. Rose, who was involved in the Burbank litigation. "In that incident, it was determined that the SWA flight crew failed to abort an unstable approach. The aircraft approached too high, too fast and too steep. The flight crew was warned by the onboard warning system, yet proceeded with a dangerously out of limits approach and failed to abort the landing when it was clear they were unable to stop on the runway."

Mr. Rose indicated that, as a cost-savings method, SWA had also decided to disconnect an automatic braking system, which would have stopped the aircraft on the runway in Burbank. As at Midway, the Burbank aircraft ran off the runway, broke through the airport barriers, 20 feet tall steel blast fences, and ran onto Hollywood Way, a busy multi-lane road, crashing into a car and injuring its occupants. Kreindler was the lead attorney in the case on behalf of the 20 families involved in the Burbank crash.

"No less important is the fact that an especially high level of caution is required whenever severe weather that could compromise a safe landing is obvious and when runway conditions deteriorate," said Marc S. Moller, an aviation attorney and partner at Kreindler & Kreindler. "Weather doesn't cause accidents; people do. The fact that other aircraft safely landed last night before Flight 1248 and that the runway condition was reported as 'fair' would seem to suggest that there was something different about this plane's approach and landing. The 737-700 involved in the Midway crash should have had the auto brake system installed and, if used, that should have stopped the aircraft, given a normal and stable approach by the flight crew. Yesterday's crash is not the first in bad weather that should never have happened."

Originating from Baltimore-Washington International Airport last night, the landing of SWA's Boeing 737 killed at least one child on the ground and seriously injured several others as the plane overran the runway and plowed onto Central just south of 55th Street adjacent to Midway Airport.

About Kreindler & Kreindler LLP

Founded in 1950, Kreindler & Kreindler LLP (http://www.kreindler.com) is nationally recognized as the first and most prominent aviation law firm in the nation. With offices in New York and Los Angeles, the firm has been the leading plaintiff legal counsel on hundreds of aviation cases, including major ones such as the September 11 terrorist attacks, Pan Am Lockerbie Flight 103, Korean Airlines Flight 007, and American Airlines Flight 587, and many cases of small private and commercial crashes. The leading legal textbook in the aviation field, "Aviation Accident Law," and a standard legal treatise, "New York Law of Torts," were authored by members of the firm. The firm has handled many cases stemming from weather-related accidents, including World Airways Flight 30, Boston, MA (runway overrun due to ice); USAir 405, New York, NY (icing on takeoff); and Continental 1713, Denver, CO (icing on takeoff).

Marc S. Moller: Kreindler law partner who has represented thousands of victims of commercial and general aviation disasters, and litigated accidents involving single-engine, multi-engine, helicopter, corporate jet and military equipment for more than 25 years. He is presently the Plaintiffs' Liaison Counsel for all passenger and ground victim tort litigation arising from the September 11, 2001, terrorist attacks, and is an internationally recognized expert in aircraft litigation.

Daniel O. Rose: Kreindler law partner specializing in litigating airline, general aviation and military crash cases, as well as other complex products liability and negligence cases. Mr. Rose served in the United States Navy as a carrier-based attack pilot including service in Operation Desert Shield. He is a multi-engine commercial and instrument rated pilot.





--------------------------------------------------------------------------------

Source: Kreindler & Kreindler LLP



************************************************************ ************





Judge Mukasey, as I am sure you are aware, after the TWA 800 accident in New York, the Aviation Disaster Family Assistance Act of 1996 was passed. This code contains the following:



"(2) Unsolicited communications.--In the event of an

accident involving an air carrier providing interstate

or foreign air transportation, no unsolicited

communication concerning a potential action for

personal injury or wrongful death may be made by an

attorney, representative of an attorney, insurance

company, or air carrier litigation representative to an

individual injured in the accident, or to a relative of

an individual involved in the accident, before the 30th

day following the date of the accident."



This press release would seem to violate the word and intent of the Disaster Act. Sir, I am not an attorney, but in my mind a simple test applies as to whether this is a solicitation– if it looks like a duck, walks like a duck, and quacks like a duck, it is probably a duck.



What other possible motive would Kreindler and Kreindler have for distributing this press release other than to solicit potential plaintiffs? The answer seems obvious.



I look forward to your reply.





Sincerely,

[Jacob TwoTwo]

Generally, it takes more distance for an aircraft to take off than it does for it to stop.

A go-around would be feasible from the point of touchdown in a commercial aircraft, as airspeed is reasonably high at that stage. However, once braking starts to occur, deceleration can be fairly rapid.

The situation you are asking about, where the pilots find that they have insufficient runway to stop and so decide to take off again, would be unlikely. In almost every case, one would need far more runway length to get back up to flying speed and become airborne.

Thus it is generally better to stick to the "stop" plan, even if it isn't quite working out.

Jacob TwoTwo

[westhawk]

Now if only USA Today, The Wall Street Journal or The New York Times would do a story on this well-known practice of ambulance chasing...... It's just a thought:{

Westhawk

[gofer]

Picking up on Astrofan's theoretical case here and accepting JTT's and 4G's "committment" once stopping has started on Terra Firma.

Apart from the normal - reverse thrust, brakes & spoilers - logic, would anybody in their right mind consider pulling up the u/c as a potential way of getting much more "rubbing off" of speed. I realise this is drastic, but can think of a few excursion territories that might be considered more risky... not many I agree but...

That should cause some interesting remarks - and before you all jump on me.... Like Astro, up to now my life has depended on your skills and yes we do about the same no. of hours a year in the air as drivers and their firemen (ups sorry co-drivers) do for most airlines.

Cheers Gofer

[tribo]

With respect to 'Runway In Use' and 'Operational limitations' - an UK perspective as found at

www.ais.org.uk

____________________________________________________
UK

AIC 39/2002 (Pink 30) 2 May

ADVICE TO PILOTS, AIR TRAFFIC SERVICE STAFF AND AERODROME AUTHORITIES CONCERNING THE SELECTION OF 'RUNWAY IN USE' AND OPERATIONAL LIMITATIONS

1. This circular reminds pilots that, irrespective of the runway direction selected by Air Traffic Control, or notified by Flight Information Service Operators, Air/Ground communication service radio station operators or the Aerodrome Authority, it remains the pilots responsibility to obtain the lates weather and aerodrome information and to decide whether or not his or her skill, overall experience, and recent flying experience on the particular type of aircraft will enable a safe take-off or landing to be accomplished in the prevailing wind and runway surface conditions.

2. The runway in use will normally be that most closely aligned to the surface wind direction but may vary because of local operational restrictions or procedures. ATC staff at aerodromes can assist pilots of aircraft, particularly light aeroplanes and gliders, by offering, whenever possible, the runway most into wind for take-off and landing if this is not the runway in use.

3. A pilot who is unable to accept the runway in use should advise ATC, the FISO or Air/Ground communication service radio station operator that the crosswind (or tailwind) on that runway is outside his or her limits and request the use of a more suitable runway. Use of an alternative runway may entail some delay while aircraft movements for the runway in use are reorganised by the ATC unit, or a suitable break in other traffic occurs at aerodromes at which a Flight Information Service or Air/Ground communication service is provided. Pilots should recognise that, in some circumstances, the only suitable alternative runway may be at another aerodrome.

4. It is important for Air Traffic service staff and those responsible for the operation of the aerodrome to understand that the crosswind limit for some types of light aircraft is low and also that, although within the crosswind limit for the aircraft, the pilot concerned may not be sufficiently experienced or current on that particular type to attempt a take-off or landing in the prevailing conditions.

This circular is issued for information, guidance and necessary action.
____________________________________________________

[Clandestino]

Retracting the U/C on the ground was attempted at least once, (http://aviation-safety.net/database/record.php?id=19940315-3) but it didnt work. Actually you get better decceleration by using wheel brakes than sliding down the runway on your belly.

[Farmer 1]

Retracting the undercarriage while on the ground should be impossible, because of the weight-on-wheels switches.

[vector4fun]

It should be noted, that while 31C had a tailwind component, it also has the lowest RVR minima, 4000'. I understand that vis was pretty close to minimums at the time of the approach, and 4R wasn't plowed. So it's likely that 31C was the only legal option, even if it was a very poor one... :(

[Clandestino]

Retracting the undercarriage while on the ground should be impossible, because of the weight-on-wheels switches.
Not always. (http://aviation-safety.net/database/record.php?id=19900221-0) Some airplanes have override switches and if there isn't one you can always be imaginative at circuit breaker pulling. Well, you shouldn't be, but...

[RatherBeFlying]

Cranbrook accident summary on ASN (http://aviation-safety.net/database/record.php?id=19780211-0)

Much worse than running off the end or hitting a snow plow truck is having a reverser deploy in the air just after takeoff.

[Willie Everlearn]

to: theflightline :confused:

Interesting comment. I appreciate it but, what's snow and how do I calculate what a knot is??? Who ever heard of a whiteout? Isn't that what you use on paper when you make typing errors? :confused:

Willie Everlearn (I guess not)

Maybe that's what all this white stuff is all over the ground up here in Canada. Snow.

[arewenearlythereyet?]

Willie, you already blew it with your first response that I pointed out shows you out to be a Walter Mitty. If you are a sim instructor on anything bigger than an IBM laptop then I'll eat my hat. I'm also confused about the SWA policy on the use of Auto Brake. (I have no idea what it is but some air carriers have a DO NOT USE policy. Are they one of those airlines?)
With auto brake selected for landing, why would the crew assist the auto braking by applying Manual brakes? The auto brakes I'm familiar with disengage when manual brakes are applied. So, I do find the sequence of events rather puzzling, don't you? One more point on auto brake. I've been lead to believe that auto braking is more effective and efficient than we humans. Have you heard that as well?With statements like that above, you have only confirmed that you have no real idea about what you write except that gained reading the instructions that arrives with your latest copy of MS Flight Sim. Why, oh why, do we have to put up with pretenders on these forums? I don't mind the honest questions from pax such as the ones about trying to get airborne again after landing or retracting gear once on the ground. At least they have the decency to tell us that they are indeed not pilots, certainly not airline pilots, and therefore allow us to explain why some things are or are not done.

There are far too many 'pretenders' on this thread who are trying to come across as experienced with the type of operation as the carrier in this accident and then submitting their views as though they know what they are talking about when in fact all they are doing is p!ssing off those of us who are able to spot their Walter Mitty type ramblings which get in the way of reasoned debate based on experience. By raising the matter about autobrakes, Willie Mitty tries to infer that it is possible that Southwest have a policy of not using autobrakes when in fact anyone in this industry who is a B737 pilot, especially those of us who work for companies registered in the first world, know that it would be impossible to even get an AoC if someone were stupid enough to even think of implementing such a policy.

If Wille Mitty Everlearn is a sim instructor (and we don't mean the Microsoft version) and he comes out with more rubbish such as "... I've been lead to believe that auto braking is more effective and efficient than we humans. Have you heard that as well?" then why does he suppose that I, and no doubt most of my colleagues, who do actually fly and operate these types of aircraft into those types of airports in those kinds of weather conditions, should even try and answer him when anyone who is trained on the B737 will know which autobrake settings are the equivalent to maximum manual braking and which are only a deceleration rate.

It's bad enough that some media types read these forums and are fooled by the likes of these Walter Mitty's and then raise the topic as though it is learned opinion when in fact it is little more than wittering s of someone who knows a little about something and nothing about a lot. This forum should be for educated debate and not for eejits to make stupid assumptions or statements about why they think they know all the answers already and are prepared to be judge, jury and executioner.

Those of us who need to will learn from this accident. All the others will get their titillation and continue to try and bluff their way amongst others who know less. :rolleyes:

[innuendo]

posted 11th December 2005 18:18
--------------------------------------------------------------------------------


"I understand the ABS isn't much help on a dirty runway if you don't plant it on the numbers."

Hmmm, I wonder how the "ABS" (sic) knows if it was "Planted on the numbers" or not.

[dallas dude]

arewenearlythereyet,

quote......"Willie Mitty tries to infer that it is possible that Southwest have a policy of not using autobrakes when in fact anyone in this industry who is a B737 pilot, especially those of us who work for companies registered in the first world, know that it would be impossible to even get an AoC if someone were stupid enough to even think of implementing such a policy."

FYI..The FAA allows US carriers to set their own policy regarding mandatory use of such.

My carrier has a requirement to use autobrakes (if installed-former TWA MD80's aren't so equipped) if the visibilty is below 4000' or 3/4 mile, if the runway is contaminated and if the runway is shorter than 7000'.

As I understand it, SWA did not have a policy requiring use of autobrakes, at the time of this event.

dd.

[BOAC]

May or may not be relevant to this accident, but I had a very exciting moment or two in KEF at the roll-out end of R02 last winter, following which it was discovered that the last 1000ft or so was NOT grooved like the rest of the runway and it had a b/a of almost zero in snow. It was just that no-one had reported or notammed it until then................................

[boofhead]

Paper today said the crew had trouble getting the reverse thrust levers to move, they might have been distracted by this and if not using auto brake might have delayed the stopping process?
If the throttles are not fully closed the reverse levers will be hard to move and even jam until the throttles are properly closed. This has happened to me and others several times in the sim, but luckily not in the airplane.
In these circumstances any delay would be a bad thing.

[Flyingphil]

So, latest Update from an Yellow-Press-german Paper (This means: ACCEPT THIS INFORMATION WITH CARE!)

The Capt was a 58-Year Old Veteran being with WN since 1978 having logged almost 19.000 Fhrs in Total

The F/O seems to be a 32-Old Guy having accumulated about 4.700 Fhrs Total and was recently hired after Serving some years with another 737-Operator (I assume he was laid off from either ATA or UAL)

If the CPT is really that old I think this was unfortunalety his last flight.
Investigations normally take months and I assume WN will take him out of Service untill it is proofed that this was in the first line (Or totally) a technical Error if his licence is not frozen yet by Administratives.
This would protect him to be part in another incident that might will happen and WN would be protected against the bad press etc in such a case.

As far as I know, Pilots in the US are not allowed to operate pax-planes after their 60th Birthday (For Cargo I am not sure).
So, if Investigations take more than 6 Months he will most propably not return into the cockpit:{

[acm]

The performance figure for landing on contaminated runway in 737-700QRH, are based on "two engine detent reverse thrust"

If the reverse doesn't work, the landing distance, which are advisory by the way, consequently much longer.

Flaps 40, Braking action Medium, 60'000kg/132'000lbs Max Manual Braking, Landing distance = 5955 feet. ( factored by 15%)
How can you land in Midway ?

[TR4A]

Flaps 40, Braking action Medium, 60'000kg/132'000lbs Max Manual Braking, Landing distance = 5955 feet. ( factored by 15%)MAX Landing weight in a -700 is 128,000 lbs.

[FakePilot]

What happens during an attempt to activate the thrust reversers if for some reason the weight of the plane is off the wheels? Such as, the pilot attempts to engage the reversers during a bounce? Do they just open when the weight settles, or do they have to be cycled closed and back open again?

[acm]

MAX Landing weight in a -700 is 128,000 lbs.

OK, at 121'000/55'000kg, Landing Distance=5'565 feet, with both reverse...

[Willie Everlearn]

arewenearlythereyet?

Well my friend, I guess you better get your hat out and start eating.

FYI, I’ve got more time on wide bodies than I have on any version of MS Flight Simulator. What’s wrong with FS players anyway??? As an old guy, I find the hot keys a bit tricky so I’ve asked Santa for a joystick. Think it’ll help?

If you think it's the descent thing to do, then I must confess, I’m not a passenger, I’m not a wannabe, I don’t even play Flight sim all that much, but I am a bona fide ATPL. In fact, I hold three ATPLs (2 active) and 5 Type Ratings, one of which is the B737.
You?
And, let’s not turn this into a “my dogs bigger than your dog” pissing contest. You’re the one with the ‘qualification’ issue, eejit.

There ARE far too many 'pretenders' on this thread, aren’t there? I hope that comment isn’t too far off the mark as far as you’re concerned. You sound like a nice man. A little O.T.T., but we all have our eccentricities.

As I’ve already said, I have no idea what SWAs Auto Brake policy is. Does it take a FS2004 wannabe to ask that kind of question??? Don’t think so. Besides, I'm not a wannabe or a wishiwas.

Having taught several U.S. companies directly from their own SOPs, I can tell you I’ve seen Auto Brake policies that would amaze you. I’ve also read other interesting SOPs that make me wonder about a specific SOP within an SOP and why it’s there? Who’s doing the thinking and decision making on the Flight Deck? The Company, or the crew???

“By raising the matter about autobrakes, Willie Mitty tries to infer that it is possible that Southwest have a policy of not using autobrakes when in fact anyone in this industry who is a B737 pilot, especially those of us who work for companies registered in the first world, know that it would be impossible to even get an AoC if someone were stupid enough to even think of implementing such a policy.”

I’d be careful with statements like that. It IS possible.
AoC???
Look deeper into FAR Part 25 (or JAR 25). What part does Reverse Thrust and Auto Brake play in the AFM landing charts? Okay. Now try your question.

“If Wille Mitty Everlearn is a sim instructor (and we don't mean the Microsoft version) and he comes out with more rubbish such as "... I've been lead to believe that auto braking is more effective and efficient than we humans. Have you heard that as well?" then why does he suppose that I, and no doubt most of my colleagues, who do actually fly and operate these types of aircraft into those types of airports in those kinds of weather conditions, should even try and answer him when anyone who is trained on the B737 will know which autobrake settings are the equivalent to maximum manual braking and which are only a deceleration rate.”

Wow! So, you’re a real hairy ast airline pilot. I'm impressed. You’re so lucky! I bet you get all the girls.

But since you asked, at high speeds, thrust reversers and speed brakes make up approximately 80 percent of the total deceleration capability with brakes providing the remainder. I’d say braking and getting stopped was an issue at Midway. Just a guess….

So did they use reverse to the end as well as manually brake or were they autobrakes 3? Simply questions, simple concerns, in’it??? I’m not rushing anyone to judgment, just askin’ da question.
(Bottom line is none of our business, it’ll all come out in the NTSB wash anyway)

This is a pilot rumour network. Eh? Not wanting to sound uncertain, let me say this, you can’t brake your aircraft as efficiently or effectively as an Auto Brake System. Full stop.
Any more questions, Wally?

“It's bad enough that some media types read these forums and are fooled by the likes of these Walter Mitty's and then raise the topic as though it is learned opinion when in fact it is little more than wittering s of someone who knows a little about something and nothing about a lot. This forum should be for educated debate and not for eejits to make stupid assumptions or statements about why they think they know all the answers already and are prepared to be judge, jury and executioner.”

I don’t have a comment on this paragraph because I agree you. Only what’s implied doesn’t apply to me cause I’m not interested in pointing the finger or blaming the crew. Anyone could end up with the same result under the same circumstances. But you have to be in this industry long enough to know that and you will eventually, so don’t worry about it.

Keep the blue side up. It's been a slice.

Willie Everlearn (some days, I’m not so sure)

P.S. Enjoy the hat! I have to Google Walter Mitty.
:ok:

[smokey762]

Yo Willieeverlearn

If auto brakes for landing exceed the pilot's capability to brake, why then must the pilot exceed MAX to regain control of braking?
The answer is MAX Auto Brake IS NOT MAXIMUM AVAILABLE BRAKING. Max available braking for landing can only be obtained by manually standing on the brakes. In the 700 you must exceed atobrake pressure by even more than in a 300 to regain manual control.

[Mr Hankey]

The important point here is that the reason why you would have to be a bone head to even consider not using autobrakes ( are there really airlines that have an option to use them!?), is that the really significant factor is how long it takes to to get the brakes on manually. Boeing says that manual application of brakes usually has a delay of 4-5 sec compared to autobrakes. THis would chew up 1000' of runway.

I hope they selected max autobrakes and full reverse and then tried a max manual brakes after it started to go pear shaped, otherwise things will be sticky.

[Halfnut]

1. Are the 737NG the thrust reversers are locked out inflight?

2. If so what does it take to unlock the 737NG thrust reversers?

3. What inter-locks are there before you can get full reverse thrust on the 737NG?

Thanks

[Willie Everlearn]

smokey762

Thanks for your response.

It seems as though I'm not making myself clear enough on this point. Let me try again?

There have been tests (as you would expect) conducted to analyze the application of braking by both the human and the ABS.

The data revealed that humans, under the full and complete belief they were applying Maximum Manual Braking by pressing as hard as they could (standing on the brakes, that is) that when compared to the ABS, measurements indicated there remained additional Manual Brakes available. Does that imply we can find ourselves in a situation where we 'think' we've applied the maximum available manual braking. I think it does. (But that's me. You may have another interpretation.)

I agree with your comment. However, studies would suggest and validate the ABS to be far more efficient and effective than manual braking. By this I mean the ABS applies a more constant than the human. We tend to adjust or vary pressure over the nano seconds, as we gain a feel for the pedals and braking. (That's what the scientists suggest, not me, I just think it stands to reason so I've accepted their suggestion on this). So it would seem to me an interpretation as to when and how we apply brakes under varying conditions which could prove disasterous. Timing must be everything, eh?

Now, when you bring the ABS setting into the picture, it's a slightly different story. Obviously, deceleration rates for Autobrakes 1 isn't quite the same as with Autobrake 3. Even I understand that. But, I don't recall RTO as a normal setting for landing. And as I've said, I'm not sure most would go with manual brakes over ABS, especially on a contaminated surface.

With the Auto Brake switch set to MAX or RTO, the deceleration values are given as 14 ft/sec/sec at a speed greater than 80 Kts and 12 ft/sec/sec at a speed less than 80 Kts. In both cases (MAX/RTO) the brake pressure application is 3000 psi. The Hydraulic psi lessens with lower Auto Brake settings. I'm curious about any value beyond 3000 psi the human is able to provide. I don't dispute what you say, I'm just wondering how a 3000 psi HYD system supplying 3000 psi to MAX or RTO settings is overridden by the crew? Let me think about that.

I believe, to regain manual control of the braking all you have to do is apply manual brakes during auto braking. (AOM, Vol. 2 Landing Gear System Description) The pilot application of manual brakes does nothing to assist auto braking. My impression is that it simply disarms the auto brake regardless of setting.

:ok:

[satpak77]

The important point here is that the reason why you would have to be a bone head to even consider not using autobrakes ( are there really airlines that have an option to use them!?), is that the really significant factor is how long it takes to to get the brakes on manually. Boeing says that manual application of brakes usually has a delay of 4-5 sec compared to autobrakes. THis would chew up 1000' of runway.

It is my understanding that SWA does not advocate the use of autobraking and encourages manual braking, part of their culture to keep pilots "in the loop"

[Mr Hankey]

This is amazing! So SWA is more interested in keeping pilots in the "loop" than stopping in the minimum distance, particularly on a contaminated runway?

They had better get that cheque book out to pay a few billion in compensation, that sort of policy is dangerous.

[fepate]

This is amazing! So SWA is more interested in keeping pilots in the "loop" than stopping in the minimum distance, particularly on a contaminated runway?
Well, the accident brief for the Burbank overrun claims that, on a wet runway, maximum manual brakes can be more effective than maximum autobrakes (www.ntsb.gov/publictn/2002/AAB0204.pdf):
At the request of the Safety Board's Airplane Performance Group, Boeing ran stopping
distance simulations for this accident wherein maximum, medium, and minimum 737 autobrake
applications, as well as maximum manual brake applications, were simulated for wet runway
conditions after the 182-knot touchdown. These data indicate that the accident airplane would
have required about 5,000 feet of runway length after touchdown to stop using maximum
autobrakes and about 4,700 feet of runway length after touchdown to stop using maximum
manual brakes.

[the_hawk]

For me - as a pax and enthusiast - there are only 2 explanations for what I get to read here

a) after all these years in an industry full of rules, regulations and safety concerns still nobody has enough data on performance on contaminated runways, especially on performance difference between manual and auto braking

b) there is not much difference between the two methods and it is at pilots (airline?) discretion, especially with the possibility of using both (with timing based on experience being crucial)

I hope someone can confirm it's b) or some c) I have overlooked ;)

[safetypee]

For the professional pilots in this forum and those who hope to join the industry as such, then downloading and viewing the presentation on approach and landing (www.flightsafety.org/ppt/managing_threat.ppt) is a ‘must do’ activity.

Also print the notes and keep a copy in your Nav bag for reference.
Most of the speculative issues discussed above are covered and there are additional references and links.

Of interest and relevance in this thread are the quotes:

“Attempts to land on contaminated runways involve considerable risk and should be avoided whenever possible.”

“The friction level of a Concrete runway is not as good as ‘black top’ Tarmac, which is not as good as ‘high friction course’ Tarmac. Beware of rubber deposits on all surfaces particularly on wet runways.”

The last one is of particular interest as I recall that Midway is all concrete, and according to the last Google photo, there were considerable and lengthy rubber deposits on both ends of runway 13/31.
--------------------
Airspeed and Upwardness

[VH-Cheer Up]

These data indicate that the accident airplane would have required about 5,000 feet of runway length after touchdown to stop using maximum autobrakes and about 4,700 feet of runway length after touchdown to stop using maximum manual brakes.

Sure, on the assumption everything went well and the manual braking was commenced at the optimal, i.e. earliest possible, time in the roll-out.

But what happens if there's some finger-trouble, or a moment's human hesitation on the flight deck?

I reckon I'd back the Autobrakes to stop me quicker than manual, more often than not. I'm sure the Boeing test pilot can glean a better result under test conditions. But these conditions were more test-ing, than test conditions, weren't they?

They must have invented the Autobrakes for a reason, and I'm sure it wasn't just to push up the price of an airframe.

VHCU

[RatherBeFlying]

I believe that after Cranbrook, the reverser logic was altered to prevent in flight deployment. Reports that the crew had difficulty selecting reverse indicate that the reverser interlock logic may have got in their way.

As far as pedal vs. auto brakes are concerned, the end result is an integration over distance of:

brake pressure modulated by ABS
times
available friction.

Over the last few days I have had occasion to experience ABS in the car over a number of contaminated surfaces.

The absolute worst surfaces are those that have been partially treated in temperatures near the freezing point. The snow melts and then coaleases into what I can only characterise as grease over an ice layer. There ain't any braking action period on that stuff:uhoh:

It seems there were pilot reports of poor braking action at the departure end -- which does seem consistent with only some 90 kt of deceleration over some 5000 ft. I'm wondering if a V1 reject with partial reverse would have ended up in about the same place.

[fepate]

Sure, on the assumption everything went well and the manual braking was commenced at the optimal, i.e. earliest possible, time in the roll-out.
I absolutely agree. But given that the pilots that day were most likely prepared to get on the brakes as soon as they landed, the use of or lack of autobrakes shouldn't be as big a deal as has been made out so far in this forum.

[forget]

Dec. 11, 2005, 3:56PM
Auto-braking shut off on Southwest jet that crashed

Associated Press

CHICAGO - The Southwest Airlines Co. jet that skidded off a snowy runway and into a Chicago street, killing a 6-year-old boy in a car, was equipped with automatic brakes, but the carrier's chief executive says the system was turned off so that the pilot could manually control the plane's landing. Chief Executive Gary Kelly also said the plane had been serviced the day before Thursday night's crash and showed no mechanical problems.

It was the first fatal crash in Southwest's 35-year history.

During a news conference at Southwest's Dallas headquarters before he left for Chicago, Kelly said it was too early to pinpoint the cause of the accident, which occurred during a snowstorm that reduced visibility at Midway Airport to between one-fourth and one-half mile.

Kelly said the role, if any, of the brakes won't be known until federal officials finish their investigation, which could take many months. The National Transportation Safety Board began its investigation within hours of the accident.

Kelly, however, defended the airline's policy of having pilots turn off the automatic braking system.

"We let our flight crews make the determination to brake the aircraft," he said. "It's just a choice, and we think that it's been obviously very, very successful over a long period of time."

Automatic brakes have been used on commercial airliners for many years, but they are not on all planes. For example, JetBlue Airways Corp. operates Airbus jets with auto-brakes and Embraer planes without them.

Jenny Dervin, a spokeswoman for JetBlue, said the airline requires pilots to use auto-braking under some low-visibility and bad-weather situations but declined to say whether that would have included Thursday night's conditions in Chicago.

At Delta Air Lines Inc., "They are on our fleets, and yes, they are used," said spokeswoman Gina Laughlin. She said pilots had some discretion in when to use the auto-brakes.

Officials at other carriers did not return calls or declined to comment on their policies.

On the Boeing 737-700, the automatic brakes are accompanied by an anti-skid system. They work like the antilock brakes on a car, using sensors to apply and release brakes quickly to prevent a skid.

Modern airliners are highly automated — on autopilot, they can take off, fly and land without human intervention — but pilots frequently override the automated systems.

Boeing does not tell airlines when pilots should use auto-brake systems, said spokeswoman Liz Verdier.

"There is not a right or a wrong way to do that," Verdier said. "They are used or not used in accordance with conditions or airline operational procedures." She said she saw nothing unusual in Kelly's statement that Southwest doesn't use automatic brakes.

At the federal safety board's request, Boeing on Friday sent an investigator and a systems engineer to help with the probe into the cause of Thursday night's accident.

The crash was reminiscent of a March 2000 accident in which a Southwest jet overran a runway at Burbank airport in Los Angeles, stopping just short of a gas station. The safety board said the accident was probably due to the crew landing the plane at too fast a speed.

In its final report on the Burbank accident, the safety board said the pilots probably could have kept the plane inside the airport fence had they applied maximum manual brakes immediately on touchdown.

The plane involved in Thursday night's accident was delivered to Southwest in July 2004. Southwest operates only Boeing 737s, and the 700 is the latest update to that model.

The plane had undergone a routine maintenance check Wednesday in Phoenix, Kelly said.

"There were no indications that the aircraft was experiencing any kind of maintenance problems," he said.

Southwest has no immediate plans to change operations at Midway, one of the carrier's largest operations with 196 daily departures. Southwest had operated there for 20 years without a previous incident, said Kelly, who termed the 6,500-foot runway adequate.

Still, the accident raised questions about Southwest's operations at smaller airports, some of which, like Midway, are surrounding by houses and commercial buildings.

Some Dallas residents have raised safety arguments against Southwest's plans to expand long-haul flights from Love Field. Kelly said Thursday's accident should have no bearing on the debate in Congress over expanding Love Field, which has an 8,800-foot runway.

"They are obviously different airports with different runways and different configurations," he said.

[the_hawk]

On the Boeing 737-700, the automatic brakes are accompanied by an anti-skid system. They work like the antilock brakes on a car, using sensors to apply and release brakes quickly to prevent a skid.

Does that mean when a plane is equipped with autobrakes, anti-skid works on manual braking with autobrakes off, or does it mean anti-skid only with autobrakes selected / in use?

[Clampers]

I'm not too sure about the Boeing 737, but generally, autobrakes only work with the anti-skid operating, and manual braking utilizes the anti-skid, if it is functioning.

[coco-nuts]

Autopilot take-off! Im gonna try that one day!!!!!

cheers
coco

[flown-it]

As pointed out by Willie Everlearn
studies would suggest and validate the ABS to be far more efficient and effective than manual braking. By this I mean the ABS applies a more constant [pressure] than the human. We tend to adjust or vary pressure over the nano seconds, as we gain a feel for the pedals and braking. (That's what the scientists suggest, not me, I just think it stands to reason so I've accepted their suggestion on this). So it would seem to me an interpretation as to when and how we apply brakes under varying conditions which could prove disasterous. Timing must be everything, eh?

applying manual braking can and does result in one unconsiously varying the pressure to the pedals. This trait is magnified in a crosswind where one is at times walking the rudder more than normal to maintain directional control. I always use 'em and in 16 plus years they've never let me down.

Oh and did anyone see the SLF interviewed the next day who in addition to the usual "terrifying ordeal " stuff so beloved by CNN said that "We could feel the pilot pumping the brakes" Duh!! Bet he will be the first to sue his car company when he pumps his ABS equiped brakes in a skid!!

[smokey762]

Clampers

The anti-skid does work with manual braking to aid the pilot in directional control and reduce stopping distances on wet or slippery runways. For manual braking pilots are taught to apply constant brake pressure and allow the antiskid to do its' job when runways are slick or when stopping distance is critical.

[Arkroyal]

One thing I've noticed flying the 737 is that the shorter the runway/worse the conditions, the quicker pilots want to get reversers deployed, with the inevitable result that their first attempt at reverse is baulked by the interlock.

Frantic battles ensue which, had a moment's hesitation been employed after touchdown, would not be needed.

Try this whilst trying to remember to apply full manual brakes, and it is unlikely that your stopping distance will be the shortest possible.

These observations are in no way a comment on this accident.
My thoughts are with the family of that poor child.

[acm]

On the -700 the reverse are unlocked when the plane is at 10 feet RadAlt or when on the ground air/ground switch.

[Stu Bigzorst]

I am intrigued as to why an approach was made.

Braking action medium, 55,000 kg, Flap 40, 8 knot tail, Vref40+5:

AB3 = 7125'
ABMAX = 6975'

If braking action poor, then it's 9214' with ABMAX. Add 1265' if you only have one reverser, add 3335' for no reversers.

All these include 1150' of air distance, so should be compared with the 6500' of available runway. Sure, they include a 15% factor, but I (unless in an emergency) would like a touch more than 15%. So why was an approach made?

Even if they did a perfect "testpilot" (no flare) landing, it would overrun.

If they decided to go for max manual braking (totally mad on a contaminated runway - how do you slam on the brakes on touchdown AND steer at the same time?) then the figure is 6735' (8909' if braking action poor). Still too far.

A common error in the -700 when landing Flap 40 is a slightly extended flare (due to the unusual attitude). This was a particular problem when light (as they were). The grappling with the reversers problem only ever ocurred for me on the -300 (I suspect because of the 10' RA on the -700).

The -700 lands well on short runways. It also lands well (when using AB) on contaminated runways.

But I wouldn't like to try and combine the two.

[chuks]

I never tried manual braking on an airplane. It seems to work okay on my motorcycle, on the front brake at least, but I find pedal braking works much better on an airplane. There are issues of access to the brake controls and maintaining visibility during roll-out that must be addressed when using manual braking that would seem to preclude the practice.

[the_hawk]

Did the crew know of the 90 deg 10 knots wind the NTSB gave us in the press conference? Or did they get an older value like the 23003KT from the 0153z METAR?

[fepate]

Did the crew know of the 90 deg 10 knots wind the NTSB gave us in the press conference? Or did they get an older value like the 23003KT from the 0153z METAR? I think the accident happened at 0115z (but I'm not so good with time zones). If so, the preceding METAR was this one:
KMDW 090053Z 10011KT 1/2SM SN FZFG BKN004 OVC014 M03/M05 A3006 RMK AO2 SLP196 R31C/4500FT SNINCR 1/10 P0000 T10331050

[Airbubba]

>>...R31C/4500FT SNINCR 1/10 P0000 T10331050

I don't have my Microsoft Flight Simulator decoder ring handy. What does this secret stuff mean?

Hopefully nothing significant.

How many crashes do we need to get human readable notams and weather?

[vector4fun]

I believe that indicates an RVR of 4500' on rwy 31C. I wouldn't hazard a guess on the rest without a cheat sheet. If so, it confirms the other runways weren't available because the vis was below mins for them.

[Keygrip]

An RVR of 4,500' - is that an oxymoron?

[AMF]

The aircraft landing just prior reported "fair to poor" braking action.

In the meantime, heavy snow was falling. Braking isn't going to magically get any better since the report, more likely worse. We're paid to know this, and factor possible deterioration it into our decisions.

Midway (been there many times, summer and winter) = short runways = not a lot of margin for error even on good days.

Contaminated runway

Known tailwind

Autobrake vs. manual max braking.....semantics. The aircraft hit the fence past the end of the runway at 40kts.....in other words, it wasn't even close.

Every landing (or T/O) involves the use of numbers, but some numbers are really variables (tw higher than reported, that braking action reports involve some degree of subjectivity and/or coefficient instrumentation doesn't cover every inch of where your wheels will be). Remembering this fact....where the numbers come from and their inherent limitations with regards to accuracy....should be of prime concern when making decisions that allow NO room for error.

Maximum-effort landings are a rare thing in airline ops...the REQUIREMENT to make one due to tight book numbers even rarer. When faced with "assuming the best" in order to make the book numbers work, that's the time to get your head out of the book and recognize that your assumptions could easily be at odds with the reality, and how does it fit in with managing risk?

Assuming the best at Dulles or O'hare etc. and being wrong means you miss a turn-off and continue to the next one. Doing the same things at Midway is entirely different.

[172driver]

R31C/4500FT SNINCR 1/10 P0000 T10331050

I don't have my Microsoft Flight Simulator decoder ring handy. What does this secret stuff mean?


RWY 31C RVR 4500ft, snow increasing rapidly; not sure about the rest

[the_hawk]

@fepate: you are correct, I have been looking at the first post of this thread where the time (and subsequent the METAR) is wrong.

Are the types of the a/c landing ahead of Flight 1248 known?

[Doors to Automatic]

I landed at London-Luton Airport in a 737 last night. Runway 26 has a turning which I guess most pilots try to make because it negates the need to backtrack.

It is located approx 5500ft from the threshold and most times in the 737 touchdown is between 1000ft and 1500ft past the threshold leving 4000ft to stop. This requires full reverse and liberal use of brakes. In other words little margin for error.

At least at Luton if it all goes pear shaped you have an extra 1500 feet past this turn to stop! However in all my times landing there we have always made this turn.

[Mark M'Words]

Had the pleasure of operating a 757 in and out of MDW last winter, I think I may have opted for ORD on this occasion, just pleased I'm not doing it this winter.:bored:

[skiesfull]

Sometimes all the experience, skills,planning,briefing and monitoring, just simply are not enough to ensure safe flight. There are still unknowns (not the Rumsfeld type!).
Such as:-
will the snow hitting the windshield at 145kts cause visual disorientation when transitioning fron instruments to visual?
will the contamination be thicker than last checked?
will the braking action still be as last reported?
are the tyres and brakes in excellent condition, or are they approaching replacement time?
will the reversers deploy instantly and evenly and be available until a safe stop is ensured?

sorry - finger trouble posted my thread before finishing!
To continue:-
The NTSB will report it\'s findings in due course and will no doubt include recommendations that may suggest a rewriting of performance calculations and a re-emphasis on techniques to be used. Tragically, this improvement in safety will come at the loss of a young life and the grief of the family and the trauma of all involved.
Speculation is human and unavoidable, but apportioning blame based on speculation is unacceptable. Despite my experience as a pilot, I still have one thought after reading incident and accident reports. Not the thought that I would have done things differently or not got into that situation, but the thought that \"there but for the grace................\".
I have a feeling that this accident report will give me the same thought.

[Permafrost_ATPL]

To go back to the auto/manual brakes issue...

I assume that just after touch down, speed brakes and reverse are going to perform most of the braking (especially on a contaminated surface). So fundamentally, whether the brakes are applied immediately by the autobrake system or whether there is a slight delay because of human hesitation in case of manual braking, the stopping distance won't vary THAT much. However... Since the important thing would be to apply reverse ASAP, I would chose to have as little distraction as possible (i.e. should I jump on the brakes now?) and leave it to the autobrakes, so that I don't mess up engaging reverse by doing so too early (or when the thrust levers have not been retarded all the way back) and ending up fighting the levers.

If indeed, as per NTSB report quoted earlier in this thread, max manual braking gives a slightly shorter stopping distance than max autobrakes, then the pilot can jump on its brakes (thus cancelling autobraking) once reverse is engaged. Sounds to me like this operating procedure would offer the least risk of messing up engaging reverse, while producing maximum wheel braking effectiveness. No?

BTW, I'm just fresh out of ATPL school (hence the alias), so I could be talking crap :-)

P

[Ace Rimmer]

But the inescapable fact is that had there been an EMAS installed - most will contain an a/c travelling at >75kts the aircraft would have made it onto the road and young Woods' family's car.

The FAA demands that a RESA of 1000ft be availible on runways used by airline traffic or failing that a EMAS. The sad fact is that this requirment has been fudged and runway with 'grandfathered rights' like Midway (and 300 more in the US alone) don't meet this requirement (from the end of the paved surface to the fence at 31C is 82ft ) and unless they require Federal funding for an upgrade or resurfacing tht type of thing they never will. Given that if you take the figures for the last 15 years or so there are an average of four (that's right four) overruns a month by airline operations the quation is is this risk acceptable? Is it not time that the RESA/EMAS requirement be extended to apply to all airports (outside US too the FAA requirement is based on ICAO standards)?

The industry dodged a bullet in Toronto with the exception of the Woods family and other lighter injuries one was dodged again at Midway (come to that Burbank too - imagine what would have happened if the a/c had slid a yard or two further and into the petrol pumps).

Or is it a case of waiting till an accident kills lots of people before action happens? (same as usual)

[Stu Bigzorst]

Permafrost,

You can select reverse in the air (10').
Autobrakes or not, they needed 7000' or more to land (according to the Boeing 737-700 QRH figures I posted yesteday).

So people can go on and on about reversers and brakes, but if the QRH says they needed more runway than what was available, then I suspect that the enquiry may be a short one.

[AMF]

And if you barely make the numbers on a contaminated runway reported as "fair" or "good", and it in fact turns out to be "fair to poor" or less, your antiskid will cycle you right off the end of the runway every time, autobrakes or manual, TR's deployed instantly or not.

Midway leaves no room for leeway under those conditions. What's the mystery here?

[RRAAMJET]

Stu - you would think so, but this is the USA, where there is a hidden level of politics called 'lobbying'....

SWA has some of the most influential lobbyists (look at the Wright repeal efforts), and I am certain all kinds of phasers-on-stun will be applied here to stop any recommendations for change to SWA's modus-operandi by the NTSB. Watch this space...

Any US corporation would do the same, BTW, not just SWA.

[M609]

Pic 1 (http://www.airliners.net/open.file/975371/L/)

Pic 2 (http://www.airliners.net/open.file/975630/L/)

Was evacuation possible from via the aft slides? Look a bit high.

[PaperTiger]

R31C/4500FT SNINCR 1/10 P0000 T10331050

RWY 31C RVR 4500ft, snow increasing rapidly; not sure about the rest

1/10 snowing 1 inch per hour/10 inches on the ground
P0000 Precipitation in the last hour
T10331050 Temperature -3.3C dewpoint - 5.0C

[Airbubba]

Some more discussion on the use of automation in this article:

Southwest pilot violated braking policy

December 14, 2005

BY MARK J. KONKOL Transportation Reporter

The Southwest Airlines pilot at the helm during Thursday's snowy crash at Midway Airport told federal investigators he used the Boeing 737's "autobrakes," a device airline officials say their pilots are told not to activate.

National Transportation Safety Board investigators said they found the autobrake switch in the "maximum" position on the flight panel. The system is designed to activate when the landing gear hits the runway.

Investigators are still trying to determine if the system was operable when flight 1248 overshot the runway, crashed through an airport barrier fence into traffic, killing 6-year-old Joshua Woods as he rode in his family's car.

The pilot's use of the autobrakes against airline policy raises questions about Southwest's braking procedures, especially for landing in inclement weather.

"It's a really weird violation of Southwest policy. . . . Maybe he was a sharp pilot, and he decided to use the technology," said Ron Stearney Jr., an attorney representing the Woods family.

"But did [the pilot] get the training to use that stuff when for all these years Southwest has prohibited pilots from doing so?

"Maybe he was not trained properly. I don't know. But the weather at Midway [Thursday] was the ultimate test, and what we had was Titanic syndrome -- relying on technology to buck Mother Nature. A plane landing in a snowstorm with seven inches on the ground."

On-time issue

Aviation sources said Southwest is preparing to lift the ban on autobrakes, but Federal Aviation Administration, NTSB and Southwest officials would not comment or provide documents regarding requests or plans to change Southwest's flight operation procedures regarding autobrakes.

Southwest spokeswoman Linda Rutherford would not provide any details, policies or flight procedures regarding the use of autobrakes because that system -- along with the plane's reverse thrusters and the tailwind landing -- have fallen under the scope of the NTSB investigation. She confirmed that using autobrakes was not Southwest policy.

A former Southwest pilot with 13 years experience said the airline's decision not to use autobrakes has historically had more to do with on-time performance than safety.

Bert Yetman of the Professional Pilots Federation said that during his tour with Southwest, pilots were told to slow planes to 80 knots using reverse thrusters before applying braking systems.

That allowed planes to stay in the air as long as possible -- with 10-minute turnaround times -- avoiding the "brake cooling period" required when brakes are used at speeds higher than 80 knots, Yetman said.

"Safety does not come into question. It's how long the runway is and how quick you want to turn around," he said.

High setting on brakes

The pilot told investigators autobrakes were at a high setting and "deployed virtually the moment the plane lands on the runway," NTSB officials said.

As flight crews began to realize the plane was not decelerating the way it should, they "took over the brakes and pressed them as hard as they could," according to the NTSB.

The plane left the runway, blasting through the airport fence near 55th and Central, raising questions about whether the short safety zone beyond the airstrip is adequate.

City aviation officials have been working with the FAA on ways to make the runway and safe zone longer. The city submitted a proposal in May 2004, which the FAA returned asking officials to "add more to this," FAA spokesman Tony Molinaro said.

There was never a deadline on when the work or study should be completed, and negotiations were not final, he said. It's part of a national effort to lengthen runway safe zones that has been in the works for five years.

Molinaro said 46 airports have made improvements and 37 still need changes. "Midway is one of them," Molinaro said. "And it's one of the challenging ones."

Another tool

In addition to the autobrakes, transportation expert Aaron Gellman, head of Northwestern University's Transportation Center, says part of the crash probe should center on whether the pilot was using the plane's "head-up display" which provides flight path guidance in low visibility landings.

"It's used in such a way that touchdown is at a very low speed and also puts you down right near the end of the runway," Gellman said. "If he was not using it, he was not using one of the major tools available to him."

Rutherford said the cockpit of the plane in Thursday's crash was equipped with the "head-up display," but she would not say whether the pilot was using it at the time of the crash.

Navigational equipment on runway 31-C knocked out in Thursday's crash was repaired and checked by 6:50 p.m. Tuesday, when the runway was open to accept air traffic, aviation department spokeswoman Wendy Abrams said.

http://www.suntimes.com/output/news/cst-nws-midway14.html

[ExSimGuy]

Probably a simple answer, but I looked at the photos from airliners posted above, and the only exit that I could see open was the stbd rear.

Admittedly the port front could not be seen in the pics, but I would have thought (wrongly?) that all or most of the exits would have been used to de-plane in this sort of situation?

Obviously if an exit would be dangerous to use for any reason, it would not be opened, but it would appear that the overwing exits, and the front stbd were not used (the rear port may have been considered to be too high with the nose on the ground, but the rear stbd was the only apparently open. (confused)

[OverRun]

Ace Rimmer

Unfortunately you've only hit the rumours spot in Rumours and News, and the subtle inaccuracies in your rumours present a picture which is not quite as it is in real life.

EMAS installed - most will contain an a/c travelling at >75kts the aircraft would have made it onto the road and young Woods' family's car
EMAS is designed to decelerate the design aircraft expected to use the runway at exit speeds of 70 knots (approach category C and D aircraft)

The FAA demands that a RESA of 1000ft be availible [sic] on runways used by airline traffic or failing that a EMAS.
Look I'm not too well up on the latest FAA but ICAO is 90m RESA required (300 ft); and the 240m RESA (790 ft) for code 3&4 aircraft is only a recommendation. I can't see the FAA as being too different.

Midway …… (from the end of the paved surface to the fence at 31C is 82ft
It was this point that made me wonder if your post was either journalistic or legalese rumour (our Texan colleagues have a pithy turn of phrase starting with 'bulls' and ending with 'hit'). The fact is that the end of the runway to the fence is 420 feet along the extended centreline. Airbubba's great links to the satellite photos show this quite clearly. There is paved area beyond the end of the runway – this is the normal paving to reduce jet blast erosion, and is not part of the declared distances. There is a jet blast attenuator fence, but this is not the 'fence' and is modestly frangible.

Given that if you take the figures for the last 15 years or so there are an average of four (that's right four) overruns a month by airline operations the quation is is [sic sic] this risk acceptable? Is it not time that the RESA/EMAS requirement be extended to apply to all airports (outside US too the FAA requirement is based on ICAO standards)? Regretably I haven't the time to go into risk nor statistics right now, so I reserve discussion for later. But I have a gut feel what the answer will be :cool:

[Nardi Riviera]

M609:
“Was evacuation possible from via the aft slides? Look a bit high.”

- Slides would be useless (dangling). No person can jump from that height without serious injury. A non-inflated slide MAY be used as a means of climbing down, for the above-average athlete. Although, with a raging fire in the cabin no doubt most people would prefer broken bones.


ExSimGuy:
“…that all or most of the exits would have been used to de-plane in this sort of situation?”

- The car beneath the inner flap of the left wing (pic 2) gives a fair perspective. When there’s NO FIRE in the cabin, why let pax onto a slippery wing and have them fall from 3 m height? The pic’s are taken long after the evac, so we don’t know which exits they used. Ground crew may have opened/closed any of them.

[Willie Everlearn]

Looking at the previously posted accident photos it appears to me the port side main entry door is open and the aft starboard service door is open. Neither appear to have their chutes deployed suggesting main entry 'walk off' evacuation. The over wing exit plug-type doors are still in place suggesting they weren't used either. With the aeroplane essentially nose down as opposed to level, I'd think the main entry door would have been the better option.
(Creative licence used by author due to the fact things may have happened in between the aeroplane coming to rest and the time these photos were taken)

To Auto Brake or not to Auto Brake? That was my question.
The newspaper article quoting the Captain would indicate Southwest has a no Auto Brake use policy.
AH HA!!!:D
take that arewenearlythereyet! (how was the hat, BTW)


As Stu Bigzorst has stated, based on the QRH figures which some have had the opportunity to look at in the slower-paced comfort of their homes, there wasn't enough runway available to prevent this overrun.

As someone has already eluded to, this was only a matter of time for Midway.


:sad: Next?

[Ace Rimmer]

Overrun:

Whoops bit of finger trouble there should have typed 70... a million apologies but you might consider these points:

Suggest you look at the FAA requirements for airports seeking federal funding for runway upgrades including re-surfacing works.

Then you might also look at the provisions of the Lautenberg Bill which Dubya signed into law a few weeks back something about 1000ft of overrun required or EMAS (albeit not until 2015) - yep the FAA's requiremts are different from ICAOs - you only have to file a difference if you don't meet ICAO standards not if you exceed them.

Oh yes, incidentally, you might also reflect that in the ICAO Annex it talks not about the runway end but the end of the paved surface. But of course this might just be 'either journalistic or legalese'

All the foregoing notwithstanding...
You might pause to consider the fact that in this case the aircraft left the paved surface at 40kts (NTSB figures not mine by the way) so the sucker woulda stopped n'est pas? Before it went through the 'modestly' frangible blast fence and perimeter fence and on to the road - which I think you'll allow it most assuredly did?

Not my stats ICAO's Go have a moan at them

Oh and BTW just how frangible is 'modestly' is that like being a little bit pregnant? As in "whoops this modestly frangible bit of blast fence just punctured my fuel tank which appears to have slightly ignited...dang".

[punkalouver]

arewenearlythereyet? says:


There are far too many 'pretenders' on this thread who are trying to come across as experienced with the type of operation as the carrier in this accident and then submitting their views as though they know what they are talking about when in fact all they are doing is p!ssing off those of us who are able to spot their Walter Mitty type ramblings which get in the way of reasoned debate based on experience. By raising the matter about autobrakes, Willie Mitty tries to infer that it is possible that Southwest have a policy of not using autobrakes when in fact anyone in this industry who is a B737 pilot, especially those of us who work for companies registered in the first world, know that it would be impossible to even get an AoC if someone were stupid enough to even think of implementing such a policy.

Not only do you come across as a pompous ass...based on what we now know about WN's policy on autobrakes, it appears your first sentence really applies to yourself along with a couple of others in your grandstanding post. Now the question is...are you able to admit your completely ridiculous looking mistake. It may give us some insight into your CRM capabilities.

[westhawk]

This NTSB update just in:

-----------------------------------------------------------------------------------

The National Transportation Safety Board today released
the following update on its investigation into the accident
involving Southwest Airlines flight 1248, a Boeing 737-700 on
December 8, 2005, at Midway Airport in Chicago, Illinois. The
airplane overran runway 31C during the landing rollout.


The accident occurred about 7:14 pm central standard
time. The airplane departed the end of the runway, rolled
through a blast fence, a perimeter fence, and onto a
roadway. The airplane came to a stop after impacting two
automobiles. One automobile occupant was fatally injured
and another seriously injured. The flight was conducted
under 14 CFR Part 121 and had departed from the
Baltimore/Washington International Thurgood Marshall
Airport, Maryland.

The on-scene portion of the investigation has been
completed. Additional fact-finding, including tests and
research, will be conducted at various component
manufacturers. The Safety Board staff continues to examine
the information provided by the flight data recorder and the
cockpit voice recorder.

Operations/Human Performance

The two pilots in the cockpit were interviewed on
Saturday. Each interview took approximately three hours.

The pilots stated that everything was normal through
the point of touchdown. Approaching the airport, weather
was of concern to them, and they listened to the ATIS (the
recorded weather update) four times during the latter
portion of the flight. They stated that they agreed with
the dispatcher's assessment of the conditions for landing on
runway 31C and backed up that assessment by inputting the
numbers into the on-board laptop computer tool.

The computer confirmed that the landing would be
within the operational parameters of the airplane and
Southwest's procedures, they said. Autobrakes were set on
MAX, and they activated after a "firm" touchdown. The
flying pilot (Captain) stated that he could not get the
reverse thrust levers out of the stowed position. The first
officer, after several seconds, noticed that the thrust
reversers were not deployed and activated the reversers
without a problem. At some point, the Captain noticed that
the airplane was not decelerating normally and applied
maximum braking manually. The first officer also became
aware of the poor braking effectiveness, moved his seat
farther forward, and also applied maximum braking. They
stated that they continued to apply maximum pressure to the
brakes as the airplane went straight off the end of the
runway and came to a stop.


Interviews were conducted with a number of other
Southwest Airlines flight crews, including the crew of the
last Southwest flight to land at Midway and a subsequent
crew that diverted to St. Louis.


Airplane Performance

Preliminary calculations show that the airplane
touched down with about 4,500 feet of remaining runway and
was on the runway for about 29 seconds. Preliminary
calculations also show that, for the runway conditions and
use of brakes and thrust reverser that occurred, the
stopping distance without hitting obstructions would have
been about 5,300 feet (the actual stopping distance was
about 5,000 feet). In addition, had the airplane landing
into the wind, rather than with a tail wind, the stopping
distance for a landing would have been about 1,000 feet
less.

Documentation of aircraft performance from the scene
has been completed to the maximum extent possible. It was
not possible to observe tire marks from much of the landing
rollout due to the fact that the aircraft landed on a snow-
covered runway and snow fell on the runway immediately
following the accident.

FDR data show that autobrakes were active and provided
high brake pressure upon touchdown. Autobrakes and manual
braking continued to provide high brake pressure throughout
the landing roll.

FDR data show that thrust reversers were activated
about 18 seconds after touchdown or about 14 seconds before
contact with the blast fence. Testing and examination of
the thrust reverser systems will continue.

Investigators have obtained the laptop computer tool
used by the accident flight crew. It will be examined and
calculations of landing performance will be compared to
flight manual data.

Eleven security-type video cameras were identified on
the airport that may show imagery of the airplane rollout or
the surface of the runway and taxiway at the time of the
accident. The videos will be reviewed.




Meteorology

National Weather Service forecasters and other
personnel were interviewed. An enhanced snow band was in
the area producing localized heavy snow due to lake
enhancement. This apparently is a somewhat unusual weather
phenomenon, as the band swath was only 20 to 30 miles wide
with snow accumulations of 10 inches right over Midway
Airport.

Midway Airport weather observation equipment and
records were examined and all equipment was working normally
during the evening of the accident.

Southwest Airlines dispatchers who were associated
with the accident flight were interviewed. Prior to the
takeoff from Baltimore, when weather conditions deteriorated
and the runway switched to runway 31C, the dispatcher
determined that runway 31C was approved for landing for
flight 1248. Runway conditions, braking action, wind speed
and direction, airplane weight and mechanical condition of
the aircraft are typical factors considered in making such
decisions. The flight was contacted twice on the way to
Midway and the appropriateness of using the runway for
landing was reaffirmed during both contacts.

Official weather observations:

Approximately 20 minutes prior to the accident, the
winds were from 100 degrees at 11 knots, visibility was «
mile in moderate snow and freezing fog, the ceiling was
broken at 400 feet, and overcast at 1400 feet, temperature -
3C, dew point -5C, altimeter setting 30.06 in. Hg. Remarks -
runway 31C rvr (runway visual range) 4500 feet, snow
increment - 1 inch of new show in the last hour, 10 inches
on the ground.

Approximately 23 minutes after the accident, a special
observation revealed winds out of 160 degrees at 5 knots,
visibility ¬ mile in heavy snow, freezing fog, sky obscured
with a vertical visibility of 200 feet, temperature -4C,
dewpoint -5C. Remarks - runway 31C, rvr 3000 feet.


Toxicology

Blood and urine samples were obtained from both
pilots. The disposition of the blood samples is being
reviewed.

Structures

The aircraft has been removed from the accident site
and was transferred to a hangar at Midway Airport. The
maintenance log revealed no writeups or deferred items for
the accident flight or several previous flights.

Professional surveyors completed a survey of the
accident scene and the geography leading up to the site to
include the locations of parts shed by the aircraft after it
left the paved runway surface and the blast fence destroyed
during the accident sequence.

Powerplants

Both engines were visually examined at the accident
site. Although the first stage compressor blades of both
engines showed foreign object damage, they were all intact
and present. Wood from the blast fence and other debris was
present in both engines. A visual examination of the
turbine sections revealed no missing blades.

The 60-day engine history revealed no deferrals or
writeups. Each engine has two thrust reverser sleeves. FDR
data indicated that all four sleeves were deployed until
after the airplane left the paved runway overrun surface.
Hydraulic system B (that runs the thrust reversers) revealed
no leaks.


Systems

The Systems Group documented the switches, circuit
breakers and controls in the cockpit. The leading edge
slat, flap, and trailing edge flap extension measurements
were taken and revealed symmetrical extension of all
devices. The measurements will be compared to Boeing
documentation to determine exact extension.

Chicago Fire Department personnel were interviewed to
determine if any switch positions or other items were
altered during the rescue effort. The Fire Department Chief
stated that the only things his people did were to
disconnect the battery and turn off the crew oxygen source.

The brakes were found in good condition with adequate
wear remaining. The main landing gear tires had acceptable
tread depth and no indication of flat spots.


Air Traffic Control

The local controller, two tower controllers, and the
tower supervisor were interviewed. All controllers stated
that they saw the aircraft lights during the landing roll,
but did not see the actual touchdown.

The investigation has revealed that runway 31C was
used as the landing runway because it contained lower
landing minimums for aircraft using the ILS approach. If
runway 13C was used, the runway most aligned with the wind,
pilots would have been unable to land because of
insufficient landing minimums.

Survival Factors/Airports

All flight attendants were interviewed. They all said
that they noted a smooth landing but that the deceleration
feeling thereafter seem less than usual. They noted that
the emergency lighting came on after the airplane came to
rest, and one flight attendant opened the L1 door to begin
the evacuation. The emergency slide deployed automatically,
but its angle in relation to the ground was less than ideal.
This caused passengers to begin to pile up around the
bottom of the slide. Rescue personnel assisted people away
from the slide. The first officer deplaned after about 5
passengers and also assisted in getting people away from the
airplane.

Further factual updates will be issued when
appropriate.

-30-

NTSB Media Contact: Keith Holloway, 202-314-6100

-----------------------------------------------------------------------------------

I reserve comment until I have had time to further consider the facts as they now appear.

Westhawk

[NigelOnDraft]

WH - interesting post... thank you. A first read seems disrepencies as follows:They stated that they agreed with the dispatcher's assessment of the conditions for landing on runway 31C and backed up that assessment by inputting the numbers into the on-board laptop computer tool. The computer confirmed that the landing would be within the operational parameters of the airplane and Southwest's procedures, they said Preliminary calculations show that the airplane touched down with about 4,500 feet of remaining runway Preliminary calculations also show that, for the runway conditions and use of brakes and thrust reverser that occurred, the stopping distance without hitting obstructions would have been about 5,300 feet (the actual stopping distance was about 5,000 feet). In addition, had the airplane landing into the wind, rather than with a tail wind, the stopping distance for a landing would have been about 1,000 feetless. Somethings either don't add up / equal the problem :(

Personally, and not pre-judging the outcome, a GIGO laptop on a Flight Deck IMHO is far less safe than a good old paper book you are used to using, you can easily see the effect of the varous factors, and have a "feel" for. In BA we now have a computer performance thing via ACARS, and I have no trust in it :( No "logic" - lightweight A319 on a good day from LHR's 13,000' gives a 10K V1-VR split - yet our mgmt say "believe it"...

[the_hawk]

Somethings either don't add up / equal the problem

The only possibility I see at the moment how the statements you quoted fit is that dispatcher and crew agreed on a better rwy condition (and braking action) than occured (than the base for the NTSB calculations leading to 5300 ft).

Anyway, the 18 seconds probably will be the primary cause, let's wait and see how this happened.

[RatherBeFlying]

Approximately 20 minutes prior to the accident... temperature [+] 3C...
Approximately 23 minutes after the accident... temperature -4C i.e. that's wet snow/slush turning into icy snow/slush:uhoh:

[Ignition Override]

1) Regarding the law suit filed by Kreindler & Kreindler, no matter what the merits of the case, the constant US obsession (no matter what the business) with liability concerns has, for many years, placed limitations on the information which might quickly be shared between a given airline's Fleet Training/Standards and its pilots. But this has also limited the speed, accuracy and potential distribution of helpful, even critical information between Flt. Ops and other pilot groups whose daily jobs on the same aircraft type(s) control the safety of thousands of passengers (and expensive cargo).

Very valuable info can be learned, without reading the misleading, edited versions in the press (most don't bother to learn the difference between a flap and an aileron, or whether the aircraft has automation etc), which is the only aviation source for the public, or waiting many months for the final results from the NTSB.

2) Do pilots out there ever land the simulator and immediately do a balked landing go-around?

My deepest condolences to the family of the child who was lost in the tragedy.

[ni7irs]

Folks,

I have watched this post with interest. Is there any doubt that the approach should have been discontinued because of the calculations posted by the NTSB? Also, how is it possible that 18 seconds could elapse before the co-pilot deployed the reversers. Finally, why did the co-pilot need to move forward? Shouldnt the copilot be in position to assist the pilot in landing?

[Halfnut]

For the sake of argument when landing on a sheet of clear polished ice the discussion of which braking system will work better autobrake vs. manual brakes is mute. A 1965 Volkswagen Beetle’s brakes could lock up all four wheels on a 737. Antiskid would use the Volkswagen’s brakes to bring the 737 main wheels up to brake release point and then cycle the brakes until the aircraft came to a stop many miles later or the brakes melted.

Using this theory at MDW I seriously doubt there was enough coefficient of braking for the argument of which system is better matters. Once the tires reach the antiskid release point you are at max braking and I’m sure this night the autobrakes at MAX were doing just as good as job if not a better job then the two guys up front who were busy fighting the T/Rs.

On the DC-9-82 (which I do know about) the autobrakes use the right brake system only for landing and both brake systems for takeoff. When the pilots use the brake peddles for manual braking they get both brake systems all the time. MED & MAX brakes will apply two seconds after the main wheels are down.

[Astrosfan]

Stu Bigzorst:

I'm a little confused.

If a 737-700 needed 7000+ feet to land at MDW as you have calculated or else an overrun was inevitable -- and we know the runways at MDW are shorter than that -- then how do you explain all the previous safe landings of WN's 737s immediately preceding this accident? Shouldn't they all -- or at least all of the 737NG landings before WN #1248 -- have wound up parked in the street if your calculations were correct? Or am I missing something?

[Stu Bigzorst]

I just pulled the figures out of my 737-700 QRH. Boeing calculated them, not me.

Maybe the snow fell heavily and the wind shifted a bit. I wouldn't have made the approach, not least because it's not allowed (t/w + contam) in our operation.

I'm sure the NTSB will let us know everything in due course.

[DingerX]

Just a clarification on reading skills:

Preliminary calculations also show that, for the runway conditions and use of brakes and thrust reverser that occurred, the stopping distance without hitting obstructions would have been about 5,300 feet (the actual stopping distance was about 5,000 feet). In addition, had the airplane landing into the wind, rather than with a tail wind, the stopping distance for a landing would have been about 1,000 feet less.

The key phrase is "for the runway conditions and use of brakes and thrust reverser that occurred".
All this NTSB calculation tells us is that, given the conditions of MDW at the time, if a 737 touches down on 31C with max autobrake, then later applies full manual braking and 18 seconds into the landing roll the thrust reversers pop out, it will need 5300 feet of runway to stop.

So either A) the conditions as understood by the crew were different then those actually existing, or B) they fully understood the conditions and pursued a landing that depended upon the timely and effective operation of thrust reversers, or C) the NTSB's Preliminary Calculations are somehow flawed, and something else (such as the Global Conspiracy of Hot Dog Stand-Operators) is involved.

I'll now duck out and let you continue bickering about autobrake vs. manual braking.

[the_hawk]

A) and B) I assume, while the crew probably knew of the t/w they might have expected less contamination / better braking action, in any case the crew certainly knew that there was not much room for error and B) is correct as well

[Willie Everlearn]

westhawk
:ok:
Thanks for posting the NTSB update. It says alot about the result and I'm sure the final report will reveal even more. It sounds to me like the crew performed to standard with an unexpected (as well as disappointing) result.
=====

Stu Bigzorst
:hmm:
In light of your calculations (undoubtedly acccurate) I think as pilots we need to also be reminded that the QRH for contaminated, ice covered and snow covered surfaces are "Advisory" and not regulatory. So I'd say Boeing (and others) would prefer at least to ensure the numbers 'look good' or 'better' than they should (at times). This seems to be a case where those figures indicated a strong potential for an overrun. If your calculations are accurate then the actual result in landing distance is probably greater than your calculations because of this.
We have to work with what we're given.

We now know as well why they landed with a tailwind.
=====

As curiosity seekers, it's easy for us to say or suggest what should have been done or not even considered following a known result. This is one way in which we acquire experience. Learning from the misforturne of others. Perhaps it's safe to admit many of us would have likely handled this landing in the same manner.

If you've been in aviation long enough, you know there are times when "there but for the grace of God" applies and of those times you may have gotten away with it.
:ok:

[Huck]

I've read that NTSB update twice, and I can't find any mention of whether the spoilers deployed....

[boofhead]

When looking at the figures posted here, remember that most of them are "Net" numbers, not "Gross". that makes a difference when considering what should have happened compared to what did happen.

Nigel, the company will select a suitable V1/Vr (called V1, Vr ratio) based on averages for the expected operation, or will accept a standard figure for the entire fleet operations. Certainly using a variable ratio will result in better numbers and a greater payload carried, but most pilots are not trained in this procedure, with a greater risk of error.

[hopharrigan]

I can't help myself; I have to make a comment about procedures.
What makes any airline think it has more knowledge about operating airplanes than does the manufacturer? Why does every airline have procedures that are different from each other, and different from the recommended procedures as published by the manufacturer, who has access to all the data out there, and is in the best position to decide what works and what does not?
I worked for many airlines, and only one (Royal Brunei) used Boeing procedures, (which worked marvellously well). Every other airline used locally designed procedures, changed every time a new Chief Pilot took up residence. One of the more aggravating ways procedures were changed was to "standardise" them with other airplane types in the fleet. Thus if there was a mix of Airbus and Boeing, or an airplane that did not have recent technology (auto brakes?), all the airplanes had to use procedures that were workable on the oldest or weakest airplanes. It dumbs down the operation and begs the question of what will happen when the old airplanes are retired, leaving the newer generation airplanes still being operated in a degraded manner. Is this a factor here?

[Halfnut]

http://abcnews.go.com/Business/FlyingHigh/story?id=1412384

Column by John J. Nance

New Report Only Deepens Mystery of Midway Runway Accident

Investigators Find Southwest Flight Needed 800 More Feet to Land Safely

Dec. 16, 2005 — - The National Transportation Safety Board has just released some preliminary information on last week's runway overrun accident at Chicago's Midway Airport, but those hoping for a quick explanation will be disappointed. The report raises new issues about what went wrong aboard Southwest Airlines Flight 1248.

This, however, is the very nature of accident investigation. Let me explain.

First, the most important consideration is that there is never, ever just one cause behind a major airline accident.

An airliner's landing sequence is a series of complex steps and decisions, all made against the background of thousands of established procedures, the company and professional culture, and legal and regulatory structures.

A single pilot decision may be based on company and Federal Aviation Administration decisions and practices, information provided (or omitted) by airfield authorities, decisions (such as the dispatcher's contribution) made in distant places, or even a sudden change in the weather. In fact, virtually all of such considerations may have been involved at Midway when the Boeing 737-700 overran Runway 31C and rolled onto a highway.

The plane crashed into a car, killing 6-year-old Joshua Woods.

The NTSB's interim report raises several issues, each of which may (or may not) be a crucial contributing factor:

1. Air-traffic control authorities chose to use Runway 31C even though there was a tail wind, probably because the instrument approach procedures to guide pilots to Runway 13C, which runs in the opposite direction, were unusable due to low visibility.

This means that if Midway's tower switched to 13C, the airport would effectively be unusable. The FAA does not shut down an airport, by the way, but it can render the airfield unusable when the weather drops below legal minimums for whatever runway is in use.

2. The pilots, in conjunction with Southwest's dispatcher (who shares legal authority with the flight captain), apparently communicated several times regarding the ability to land on Runway 31C, given the difficult conditions reported by the airport. The question is whether those conditions were reported correctly and, if not, were any significant deviations the result of human error, equipment failure, or some other systemic problem (such as delayed reports).

3. The pilots listened several times to the ATIS -- the automated radio signal broadcasting current conditions at Midway -- and used the reported figures in an onboard laptop system authorized by Southwest to determine when a landing would be both safe and legal. In aviation terms, legal means in compliance with regulations and procedures.

If the crew's conclusions were wrong, did it result from operator error (i.e., someone entering the wrong data), untimely or bad information from the ATIS, a computer program glitch, or some very human failure such as misreading the result? The NTSB will need to pay close attention to why this process designed to enhance safety apparently indicated the landing would be safe and legal.

4. The NTSB reports the crew elected to use maximum autobrakes, which would seem to be a very good and conservative decision. The report found the autobrakes began delivering maximum braking as soon as the main wheels were on the ground and, in addition, the report indicates that the aircraft touched down inside or very close to the appropriate landing "zone" and had about 4,500 feet in which to decelerate and stop. Yet, post-flight NTSB analysis shows that with the tail wind, snow conditions and slipperiness -- as well as an apparent delay in deploying the thrust reverse system on the two engines -- the aircraft would have needed more than 5,300 feet to stop. Here we have a difficult problem.

For many decades, thrust reversal was never taken into account when computing how much runway a pilot needed to legally and safely stop. Yet the NTSB says its post-crash conclusion that 5,300 feet of runway was needed is based on partial usage of thrust reversers. That would mean the only safe landing of Flight 1248 required full and rapid use of thrust reversers. This is a troublesome inconsistency.

5. Perhaps the most worrisome and puzzling indication from this report is that the aircraft was on the runway for 18 seconds before the thrust reversers deployed, and while the captain could not deploy them, the first officer was able to do so. Even if the landing was only legal with the use of thrust reversers, they are normally out and functioning within four to seven seconds of touchdown -- at least 10 seconds sooner than what happened on Flight 1248.

What the report does not mention, however, is that the aircraft itself has to mechanically "know" that it is on the ground before an interlock will permit the reversers to open. That air-ground switch system is located on one of the main gear struts, and yet another NTSB focus will be whether anything was wrong, even momentarily, with that switch. A significant delay in sending an "on the ground" message to the thrust reversers could explain why the first officer succeeded. Then again, it might not.

So the information presently available about Flight 1248 raises many more questions, but it also helps focus the investigation. It is important to remember the NTSB's job is not to assign blame -- which is counterproductive to improving air safety -- but to discover every single contributing factor that could produce a future accident.

Every such contributing element has to be found and fixed, and it is clear in the case of Flight 1248 the complexity of accident means that just pointing a finger -- at the pilots or anyone else involved -- will accomplish nothing.

Copyright © 2005 ABC News Internet Ventures

[alf5071h]

Comments and questions.
hopharrigan some very valid points, well said.

Not a 737 driver, but is wheel speed used in any of the spoiler / reverser deployment logic? On a previous type it was with interesting results on slippery runways.

Is there enough elevator power to raise the squat switches out of contact if an inadvertent forward stick input were made? With / without spoilers deployed. This has happened on other types; humans often make inadvertent inputs in marginal conditions; surprise, stress, etc.

For more information on runway reports and the increase in landing distance required on contaminated runway see the thread Good - Fair - Poor – Nil. (http://pprune.org/forums/showthread.php?s=&threadid=201987)
Note the statement “it is not practicable at the present time to determine aeroplane performance on the basis of an internationally accepted friction index measured by ground friction devices”. i.e. “There is no overall accepted certification / operational correlation between mu meters and airplanes”

Also note “On a smooth, wet concrete runway surface close to the minimum maintenance standard, the Falcon 20 tire-to-ground effective braking coefficient was found to be less than the aircraft certification requirement for a fully modulating anti-skid system. Based on this finding, the current operational dispatch factor of 1.92 for turbojet aircraft landing on wet runways at destination or alternate airports would have to be increased to a value of 2.2 to 2.4 in order to achieve the same level of safety as that which is currently accepted for dry runway operations. (Transport Canada Publication No. TP 14273E).

JAR-OPS operators are required to use manufacturers ‘certificated’ AFM data on contaminated runways; no tailwind landings. Is the US still operating on advisory data; are there differences between Boeing and Airbus operators in the US? Presumably, European standard landing data is available for both types, but do US operators request it?

Beware the human factors involved with presenting ‘advisory’ data on computers. Human nature is more biased towards a technology based solution, which may inhibit careful thought about the basis of the data and its implications.
--------------------
Unless specifically authorized everything else is forbidden.

[Chiller]

A notable omission in the above NTSB report is the mention of the activatin of auto-spoilers; probably the most critical element, after brakes, in getting the bird stopped.

[RRAAMJET]

DEFPOTEC - what I should have stated is that legally there is no credit on calculation; ie, you can have one locked out and still be legal on a slippery runway. They do not have to be operative in your landing dist. calcs.
I believe that's still the case.

[just.n.av8r]

rrAAmjet, FYI:
In my company's operation both t/r's must be operative on 737NG for landing with braking action less than good. There is also a penalty for landing distance calculation with inop t/r.

[bubbers44]

It looks like the reversers were the primary method of stopping for all of the aircraft that night. I was the first flight into Reno one morning and realized after coming out of reverse if I didn't go back into reverse on a 737 I would be off the end. I was empty. If they couldn't get the reversers out for 18 seconds, they had little chance of stopping. Midway had shut the airport down due to poor breaking action and plowed the runway prior to this crash and got a satisfactory braking action from a truck but reports were there were hundreds of feet of glare ice at the end of 31C.
FAA has pulled FDR info out of previous arrivals checking their deceleration rate on landing.

Something to think about considering a close to V1 abort on ice with one engine out.

[Ignition Override]

To repeat what someone else highlighted earlier, just when will "our friends" at the FAA use a NOTAM format which will split various groups of info into more readable paragraph? For how many decades has this garbage been printed as such?

Can this not be justified by another dead child? :ouch: Or does the FAA's "cost/benefit analysis" require even more, no matter what the primary cause is?

[RRAAMJET]

Just read those replies - thanks for that. Interesting....as someone said earlier, 18 seconds is an inordinate amount of time if rev. were required.

[The Good Samaritan]

they noted a smooth landing but

:confused: Smooth landing is not fit on runway conditions such as prevailed, and probably it explains the 18 seconds delay to deploy thrust reversers.

[the_hawk]

While the pilots said

Autobrakes were set on MAX, and they activated after a "firm" touchdown.

Now one could say they are not telling the truth, but one could also say the flight attendants can't judge a landing as good as the pilots. This leads us nowhere, FDR will tell...

[Airbubba]

>>The aircraft involved is a 737NG. The reversers on 737NG can be deployed if either radar altimeter senses less than 10 feet altitude.

Seems like there was a mishap years ago where a B-737-300 crew (Piedmont or USAir?) used an unauthorized short field technique from the -200. They closed the throttles and pulled up on the T/R levers in the flare. Unfortunately, as you mentioned the glass 73's use RA instead of weight on the wheels and a very hard landing ensued after the buckets popped while still airborne. ValuJet had similar incident where they pulled breakers on a DC-9 to try to fix a ground-air sensing problem with pressurization. Unfortunately autospoilers were fooled too, another hard landing. Ground-air sensing has subtle and significant effects to many systems on current airliners.

Here's the report on the ValuJet incident:

http://www.ntsb.gov/publictn/1996/AAR9607.pdf

With the NG's I think the reversers will still come out with weight on the wheels if the 10ft RA signal is not present due to a fault, does this sound right?

[The Good Samaritan]

Attn DEFPOTEC,

The thrust reverser can be deployed when either radio altimeter senses less than 10 feet, or when the air/ground safety sensor is in the ground mode.

This is the exact quote from Boeing technical manual.

[411A]

<<...autospoilers were fooled too, another hard landing. Ground-air sensing has subtle and significant effects to many systems on current airliners.>>

Older ones too.

As in... full ground spoilers on an L10 when landing flaps selected on final.
Just what you need after a long 10 hour flight, at 5AM in the morning...:}

[Belgique]

Lots of unconsolidated wisdom on this thread - about stopping. It may be incomplete however, there is some conflict - and it might bear summarising.
Could somebody clarify reverse thrust availability, spoiler auto-deployment and auto-braking on the 737-700?

Present beliefs (possibly incorrect):

1. Reverse is available below 10ft RA and/or? when squat switches are made (but will become unavailable if actually selected during an oleo rebound - due to one/both squat switches opening), requiring a reverse re-selection (which is possibly why the F/O later succeeded.

2. Spoiler auto-deployment depends upon the same g/a sensing system - but spoilers will immediately auto-deploy

3. If auto-braking commenced immediately after G/A sensing was "made", then de-rotation would lead to a hard nosewheel oleo bash. I believe that wheel-spin-up is required for the autobrake/anti-skid to function and modulate the brake-valves (i.e. prevent MLG wheels stopping). But wheel spin-up shouldn't be the sole trigger for autobraking. I seem to recall that an early LH A320 ran fatally afoul of that design philosophy in Warsaw. Wheel spin-up didn't happen and so most retardation functions remained locked out.

An inability to enter reverse may have just been due to a sticky microswitch. It was reportedly a hard landing however, with nosegear on very promptly,_so there would have been an oleo rebound. If that upward leap coincided with the pilot's rushed attempt to enter reverse, that failure to get into reverse would be unsurprising. The fact that the delay concerned the F/O enough to reach across and try to assist may indicate (via the timing) that the pilot reverse selection was made during a momentary ground-air sensing relay cycle caused by the oleos' decompressive rebound.
_
What a risk-ridden process stopping upon a contaminated short runway is - even without a braking policy that has nothing to do with stopping safely - but keyed to_turnaround times. Why is that? Well jet engine reverser effectiveness drops off steeply as speed reduces. Even short delays in getting into reverse can eat up a lot of runway at high speed (as the AF A340 proved in Toronto & the QANTAS 747 in BKK). Why wouldn't automatic spoiler extension have pinned any rebound by dumping wing lift? Well, firstly the rebound is due to the energy stored in the oleos (on top of any involuntary backstick). AFAIK, the spoilers and auto-brakes would be energized through that same g/a sensing circuit -so maybe the spoiler panels didn't pop up either, compounding the immediate after-effect of the heavy landing rebound. If they hadn't been on the same G/A sensing circuit, then spoiler extension could part mitigate the bounce effect of a heavy landing and help pin_the airplane's MLG's to the ground, quickly allowing the wheel spinup that's required before auto-braking starts modulating the brake-valves.
_
AA1420 revealed just how nasty the lack of spoilers could be. It causes the aircraft to remain light on the main-gear (because the lift stays on the wings)._In that scenario any attempts at hard braking just ends up with a directional instability as the airplane remains light upon its wheels and the weight transfers towards the nose. It's called "wheel-barrowing" and it can be a divergent and continuing process as the pilot attempts to use a combination of pos/neg thrust to offset crosswind effects (by steering with a cocked wrist on the throttles). In a rear-engined jet any attempts to achieve effective reverse results in rudder blanking - and that compounds directional control problems. No spoilers =>_Light on the main-gear, so with a wet runway and strong crosswind it's an ongoing_nightmare_due to_both directional control problems and a lack of stopping power. It becomes a float onwards into oblivion (as it did for the captain of AA1420). What can be done to bullet-proof the stopping evolution -particularly on short contaminated runways? Well different airplanes have different G/A sensing mechanisms at present, but although EMAS overrun (http://www.faa.gov/news/news_story.cfm?type=fact_sheet&year=2005&date=090205) provisioning is a great backstop (but greatly disruptive to ops) - an ideal system configuration standard for effective stopping would seem to be:
_
a. To firstly have the spoilers deploy on main-gear touchdown via a L+R maingear G/A sensing microswitched relay and/or have an SOP that says the PNF can manually override (as a captain's prerogative/on command) to deploy them at maingear touch.
_
b. Have the spoilers, even if manually deployed, auto-stowable by (say) any application of >60% throttle lever inc_movement (to cover the case of a decision to go -_and not stop -_due to having landed too far in). 757 had that retrofit after_AA's Flt 965_Cali crash - but for GPWS reasons.
_
c. Have the reversers dependent upon MLG x 2 (both sides)_first contact only (with any disabling_rebound effect factored out) - as few bounces will be so high that inflight reverse would be of significance. Also_provide a reverser entry_override switch_for RH seat actuation "not before" he sees the post-touchdown pitch attitude reducing towards nose-gear on. DC-4, DC-6, Constellation, SP2H Neptune etc all had this for prop reverse pitch selection. It would overcome those panic stricken moments that happened to all the above-mentioned accident crews. i.e._Just when you're really "into" stopping, the bastard designers have done it to you again (no wheel spin-up, oleo rebound, dropped throttle lever, no spoiler auto-arming, stuck microswitch or relay_etc). The pilot should always have the last word (in other words).
_
d. Have the autobrake cut-in dependent upon G/A sensing circuit #1 plus G/A sensing circuit #2 (which is nosewheel oleo depression micro-switch actuation by NLG ON). That stops brakes cutting in while NLG is still airborne and causing a heavy nose hit de-rotation. And there is a difference between maximum wheel-braking and maximum effective aircraft braking. For the former, standing on the toe-pedals will just produce wheel-lock and tire-skid on a contaminated runway (i.e. ineffectual for stopping). In the latter case, minimizing the brakes release time of the anti-skid by maximizing the weight on the wheels will stop you in the shortest distance. Despite the NTSB finding on the 182kt Burbank touchdown, that max wt on wheels will be achieved by an autobrake married to some hefty back-stick introduced after the nose-gear is on. MLG braking produces a strong nose-down pitching moment and the backstick counters that. The important and oft-overlooked nett effect is that the MLG gets pushed into the deck...... for the very best auto-braking on slick runways .
_
e._Increase spoiler panel size and deployment rate => increased effectiveness for lift-dumping, => earlier weight-on-wheels for avoiding aquaplaning and maximizing tire rotational torques (which minimizes auto-brake cycling). The less frequent the brake-valves have to modulate to permit continued wheel-spin, the more effective is the auto-braking. This would also make for safer take-off aborts. To blow the tire you must first stop the wheel (is the practical aspect). That's least likely to happen if you maximize weight-on-wheels courtesy of the spoilers. What else can you do to maximize weight-on-wheels? Per d. above, use back-stick once you are on to stay and braking is heavy. Up elevator forces the main-gears down into the ground. Conversely, forward stick (down elevator) would induce wheel-barrowing. Stopping effectively is a real science.
_
f. Add optional drag chute for when runway is both short and contaminated and there's absolutely no scope for getting things wrong (or things just going wrong -like the braking action not being what you were told by ATC). Last non-military airplane to have a drag-bag (AFAIK) was the Dassault Mystere Bizjet (aka Fanjet Falcon). Drag chutes_are very effective but they_cannot be used in strong crosswinds due to induced directional control hassles. Pax might not like the strong decel, but who really cares about that when ****z is trumpz?
_
g. Increase brake capacity and add brake cooling fans for regional operations like SWA's._Underpowered steel brakes plus short runways = very hot brakes at the gate -_and consequently give rise to ill-considered policies (like SWA's alleged nil autobraking one).
_
h. Refuse to land on wet marginal runways with any tailwind component.... and always use full flap. Any counter-claim that switching to an into-wind runway wouldn't allow landing minimas (or affect O'Hare ops) is an unconscionable "fudge". If that's the case, you then go elsewhere. Any tailwind component on a marginal contaminated runway is unacceptable (and irresponsible) risk management.
_
i. Don't add that 1000kgs fuel insurance for Mum and the kids when the weather's lousy and a diversion is possible. Heavier airplanes have inertia and a higher Vref - and are understandably_that much more difficult to stop.
_
j. Don't get in the habit of adding airspeed increments (gust factors)_when they're non-essential. Some pilots are habitually incre"mental". Every extra 5 knots over the threshold will add 15% to the braked stopping distance on a contaminated runway (cumulative extended float + ground-speed) - and it could even be disproportionately more than that when landing with a tailwind. Excess speed also must be dissipated, delays the touchdown and reduces the runway available after touchdown for the "stopping" systems to act. I'm not aware of any STOL appch technique that arrives at the threshold anywhere above the airframe's 1.3Vs.
_
k._Most factors influencing stopping power_will be additive (added weight, speed increment, excess height over threshold, induced delay, tailwind component, airfield elevation, malfunction, MEL'd reversers, company SOP's, misjudgment, poor tire tread, confusion_and surprise). It's also accepted that any cross-wind component on an icy runway will significantly detract from the efficiency of reverse (particularly for tail-mount engines) and manual braking, as well as decreasing traction for nosewheel steering.

l. "when my company introduced the NG with winglets we saw more long landings. They reduced significantly when the transition had been completed and awareness of the fact was more common. Basically it's a question of how well you fly Vref when close to the RWY". A lurking factor for prolonged float? Larger spoiler panels won't fix that.

m. "The first section of the runway had the best braking, and the last section had the worst."
To cover the possibility of snow-plowing still permitting a glaze-ice slippery slide at the runway departure end (via a quick temperature plunge), it should be mandatory for ATC to avoid this by compulsorily sand-salting the last 1000 feet to go. I'd personally prefer that measure to any reassuring RCR (or pilot) report on braking effectiveness.

_Well retarded pilots are always thinking impetus, momentum, inertia and options. They also evolve a personal STOL approach style because they know that everything's set in concrete once they've planted it on the bitumen. A safe landing starts with an appropriate approach.....for the conditions.

In true, tested, tried & trite fashion, a cavalcade of pprune experts will now point out any flaws in the above logic. But that's OK too. Overruns are commonplace & expensive. There seems to be very little fat built in to accommodate human errors (of judgment and visual illusion). The overall factors need to be re-examined and re-weighed. The review might also impact upon the confidence pilots should feel in their ability to reject take-off successfully (i.e. stop) in similar runway scenarios.
Despite: "Air traffic control reported runway braking to be fair on most of the runway and poor at the end. Touchdown was normal. There was a slight bounce. There was a 7- to 8-knot tailwind. There was 32 seconds from touchdown until the aircraft hit the fence.", it's still possible to run out of runway when things are marginal to start with. All factors must be favorably re-jigged. Max weight on wheels and early reverse is the answer.

[boofhead]

A lot of what you are saying has already been considered.
The auto brake does not bring the nose down with a thump; it is easily controllable. Having the brakes come on early, as soon as touchdown occurs, is a good thing under all conditions. Once the airplane is slowing the pilot can take over manually just by pressing the brake pedals, if that is what he wants to do. Point is it should always be armed for landing, wet or dry. Boeing philosophy. Idiot proof, it was thought, but apparently not completely so, especially when airlines think they know better.
Spoilers are essential, which is why they are automatic and if forgotten, will automatically deploy when the reverse is selected.
The problem with late reverse is due to improper operation, not design. We have all done it at some time, but usually learn how to do it right early on. Hopefully during the initial simulator periods, and not on the airplane. If the reverse is pulled with the throttle(s) not fully closed, the linkages lock up and it takes some force to push them back down, properly close the throttles, and try again. Takes time, during which the residual forward thrust, if above idle, will retard deceleration, or at best will not help to bring the airplane to a stop. Some airlines even mandate that the reverse should not be pulled until the nosewheel is on the runway, contrary to Boeing procedures, and another of the many examples of idiocy in airline management.
All accidents can be traced to management; poor policy, training, supervision, support or whatever. In this case, it is apparent that a lack of understanding of Boeing procedures, and adoption of their own variations thereof (how many other deviations from standard do they have, in addition to this one? Most (all?) airlines have this insane idea that they know better than Boeing how to operate the airplanes, never mind that Boeing is staffed by experienced people and have the advantage of knowing what works in ALL fleets, not just the tiny sample the particular airline has to work with) led directly to this accident.
Root cause. Fix it and prevent similar accidents forever.

[dallas dude]

Boofhead said..."Having the brakes come on early, as soon as touchdown occurs, is a good thing under all conditions..."

Boofhead,

I respectfully disagree with your comment. When runway length [and condition] is more than adequate, in my experience, passengers do not always appreciate such high energy retardation.

Also, as turn times become shorter (35mins) brake energy/cooling is also a [secondary] consideration.

dd

[boofhead]

Follow the manufacturer's guidance. Changing the procedures arbitrarily leads to errors, which lead to accidents.
Use an autobrake setting appropriate to the conditions. Less for dry runways and more for wet/contaminated runways.
It has been suggested that accidents or incidents occur when something happens to distract the crew after touchdown (reverse fault, speedbrake failure, crosswind, traffic etc) causing them to miss starting the braking process until later in the roll out. This might be the one thing that leads to an accident.
You can always cancel the autobrake once the landing is seen to be normal, by pressing the brake pedals or turning the auto brake selector back to a lower setting (or off).
Modern autobrakes are great, giving a steady deceleration which is much better from the passenger point of view than many pilots manage with manual braking, especially if the manual braking is left too late and a big bootfull is required at the last second to make the planned turnoff.
All very smooth, does not upset the passengers, who are more upset by crews that leave the seat belt sign on for hours in smooth conditions, or use full reverse thrust and hard braking to make the earlier turnoff solely because they are in a rush, or chatter unmercifully on the PA when they are trying to sleep, etc etc.
If you, the pilot, vary the procedures given to you by the company and something goes wrong, you carry the can. If the company varies the procedures given to them by the manufacturer and something goes wrong, they carry the can. Unfortunately, both of those cases happen all the time. If we all used standard procedures (ie manufacturer procedures as varied from time to time by input from operators) we would have a much better safety record.