Lufthansa cargo plane crash

[Spooky 2]

"attempting to stop an excessive rate of descent close to the ground by aggressive use of elevator, w/engines at idle after A/T retard".

That technique will get you the same results in just about any large airplane. Nothing unique to the MD11 here. :}

[safetypee]

Spooky, will get you the same results in just about any large airplane, but this depends on the characteristics of each aircraft – the pitch control sensitivity, lift slope, and interaction with direct lift control or compensating devices. The pitching moment due to thrust may be adverse, e.g. reducing thrust on under slung engines may cause the aircraft to pitch down.
Also, consider the retard characteristics of the A/T; some modern systems have wind (ground speed) correction.
The MD-11 is reported as having a ‘difficult’ pitch control system.

[Spooky 2]

Safetypee, tell me what airplanes use groundspeed as a component of AT operations? I'm not aware of anything in the MD11 that does this and neither the B777 or 787 use groundspeed in their algorithm architecture. Maybe it's an Airbus feature? The 777/787 use a different solutions for airspeed with the 787 using static anolog pressure put through the ADRS and coming out as "voted airspeed" which is used by the AT's. In either case there is no groundspeed vector applied to the AT solutions.

[PJ2]

Spooky 2;

The Airbus A319/A320/A330/A340-300/500 series uses what is called "GroundSpeedMini". The intent is to maintain the energy level of the aircraft in strong headwinds and/or shear conditions. It will add more than 20kts but take it off quickly, as/when required. In my experience with all 3 types, the system is very responsive; it works extremely well. I can't recall a landing when it caused us to eat up more runway due to a higher than required speed over the fence.

The computation works in concert with the FMC-entered winds given by ATC. The added speed to Vapp was limited to 15kts, (Vapp is Vref + 5kts, so we're really adding 20kts to Vref), but the GSMini will, (and has, in my experience) added quite a bit more. Below 400ft, the software will maintain sufficent energy to land at Vapp.

What I have seen both from the flight deck and in flight data is the autothrust, still engaged, (thrust levers not closed to idle), increasing thrust to maintain the approach speed as the aircraft is in the flare and speed is bled off. This almost always results in a long flare and a long, (beyond the TDZ) landing.

DonLeslie;
Agree with your thoughts on adding 5 to the Vapp - BTDT and it works. Sometimes letting the airplane just hang on Vapp is a bit too small an energy reserve. That said, I much preferred manual thrust levers in manual flight and control my own energy level.

As an aside, on the A330/340 I always tried to derotate with enough rate to beat the forward bogies to the ground before they slammed down and was successful only part of the time. There wasn't the same problem with the 345.

PJ2

[Huck]

always ck the VHF 3 antenna tip during walk around) associated with speed deficiencies in takeoff and landing phases

We had a tailstrike that hit so nose high that the antenna wasn't touched - they hit behind it - and did 11 million in damage (Subic Bay, PI).

[bugg smasher]

Good thing the antenna wasn't touched, they're expensive little buggers...

[safetypee]

Spooky, Re “ … what airplanes use groundspeed as a component of AT operations?” #259

IIRC, in addition to the Airbus described above, the Avro RJ uses something similar. During autoland operations the overall autopilot/throttle system adjusts the intended point of touchdown according wind speed; this minimises the longitudinal dispersion of the landings.

Perhaps it is of some significance that the Avro RJ auto flight system consists of half of the MD 11 system hardware; however, the algorithms are based on the MD 80, tuned for the higher lift / slower speed RJ.

[Spooky 2]

I would sure like to learn more about how that works. Can you supply a link to that information?

[wozzo]

Der Spiegel claims to have had access to an LH Cargo internal description of the accident:

- 2 bounces & then fuselage broke somewhere aft
- aircraft left runway after 2400 m and came to stop after additional 375 m, started burning

In the middle part of the cargo section were 2 pallets with inflammable chemicals, also machine guns for Saudi Arabia and unspecified cargo for US military on board.

Verunglückte Lufthansa-Cargo-Maschine hatte Gefahrengut an Bord - SPIEGEL ONLINE - Nachrichten - DER SPIEGEL (http://www.spiegel.de/spiegel/vorab/0,1518,711827,00.html)

[limelight]

from the Aviation Herald.

A statement by Lufthansa provided to Lufthansa employees on Lufthansa's internal website said, that the black boxes have been analysed by the German Bureau for Aviation Accident Investigation (BFU). The results indicate, that the airplane touched down normally in the touch down zone, however two more ground contacts followed which caused the rear of the aircraft to fracture just aft of the main gear. After 2400 meters (7880 feet) the airplane departed the runway 33L to the left, at this stage the nose gear collapsed. The airplane came to rest after another 375 meters (1230 feet). The crew left the airplane via slide 1L. Further information can not be provided due to the ongoing investigation, every (internal or external) statement must be authorised by Saudi Arabia's investigator in charge. The investigator hopes to release a preliminary report in fall 2010, which requires interviews with the crew however. The interview has been scheduled for next week (Aug 16th-20th). A final report is expected in about a year. The wreckage has been removed from the accident site and is currently being dismantled. Lufthansa Technics checks whether some of the undamaged parts can be re-used, all the rest is going to be scraped in Saudi Arabia.

The German BFU stated, that the airplane bounced after first touch down and broke on next touch down.

[Airbus_a321]

...The results indicate, that the airplane touched down normally...:confused:

...The German BFU stated, that the airplane bounced after first touch down ...:confused:

...so NOT a normal landing then := or what :confused:

[Huck]

A whole new failure mode for that airplane.

I can hear structural engineers' skulls exploding all over the planet....

[wozzo]

...so NOT a normal landing then := or what :confused:

I think "normal" should be interpreted as "nothing out of the order until touchdown" (like, fire or smoke, or a malfunction).

[SMT Member]

So on a relatively calm day, facing a very long runway, one of the best trained MD-11 crews landed, bounced twice, and that was enough to cause the aircraft to suffer catastrophic structural failure? I appreciate we haven't got any G-force readings, so impossible to determine how hard they touched down, but still, something doesn't sound quite right.

Is the MD-11, besides being not that easy to land, exceedingly damage intolerant? Or, rather, damage intolerant when subjected to a "hard" landing?

[69flight]

According to a guy who had access to the info of the initial readout of the black boxes they had several touchdowns. The first with 2G, second 3G and finally over 4G. No wonder the fuselage broke apart.

[Huck]

The first with 2G, second 3G and finally over 4G. No wonder the fuselage broke apart.

FDX 80 in Narita was like that. First touchdown was 1.7. The second was over 3 (as I recall).

[mutt]

the airplane departed the runway 33L Why did a normal cargo flight land on RWY 33L?

Mutt

[SMT Member]

Why did a normal cargo flight land on RWY 33L?

As noted earlier, 33R was closed for maintenance.

To the poster who quoted the, alleged, G-loads - many thanks. Bit more than just a "hard" landing then.

[djeskine]

Mutt

33R notamed closed for maintenance at material time

[MPH]

If,it was hard on landing... we will have to wait and see how hard is hard! In any case looks like no fire O/B, prior to the landing? But, it does have the characteristics of the Narita accident. With or without A/T hard landings are generaly pilot induced and can be influenced by meteo conditions. But, as far as I can read it was a clear day, hot and a very long runway. Temp. inversion could also be a factor prior to touchdown.

[Frenk Boreman]

So on a relatively calm day, facing a very long runway, one of the best trained MD-11 crews landed, bounced twice, and that was enough to cause the aircraft to suffer catastrophic structural failure? I appreciate we haven't got any G-force readings, so impossible to determine how hard they touched down, but still, something doesn't sound quite right.

Is the MD-11, besides being not that easy to land, exceedingly damage intolerant? Or, rather, damage intolerant when subjected to a "hard" landing?
http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/statusicon/user_online.gif

The MD-11 is a fine airplane which require no special handling skills. However it has characteristics which an MD-11 trained pilot can best handle, ie it needs to be flown as an MD-11 and not as any other wide bodies.

As far as I remember, Riyadh is a hot and high altitude airport. I had to reject a few landings which could not be salvaged when the PFs ( f/os, trainee captains )failed to recognise dangerously high sink rates prior to landing.

Temperature inversion is normally not a big factor in botched landings, but a huge on during take offs.

[411A]

As far as I remember, Riyadh is a hot and high altitude airport. I had to reject a few landings which could not be salvaged when the PFs ( f/os, trainee captains )failed to recognise dangerously high sink rates prior to landing.


You are absolutely correct...RUH in the summertime is not for the unwary.
Been there, done that....for many years.

[Green Guard]

As far as I remember, Riyadh is a hot and high altitude airport.

You are absolutely correct...RUH in the summertime is not for the unwary.

SO let's summerize it:

40 deg C on ~2000 feet MSL is "hot an high" airport ??
and should not be used by unwary....?

PS no1. Dubai with sooooo many flights per summer days, even if at ~MSL,
but >50 deg C.....is OK for "unwary pilots" ??

PS no2. In Narita on that day, shall we assume also "hot and high" airport and "unwary" pilots ?

[poina]

Nothing special about RUH, I flew there for 19 years, 10 on the MD-11 and would say very benign.
When I did MD-11 line training we were lucky enough to fly with the ex CP of EVA, who mentioned that Saudia bought their MD-11's with dual main gear shocks, which was an option. Anybody hear of this?
I saw some firm landings, but no bouncers which seem to be the kiss of death on this thing.
"Dangerously high sink rates" are not endemic to RUH, this is what we get paid for day in and day out.

[heavy.airbourne]

All you guys who do it every day do not understand that RUH might be tricky for the "unwary", please consider that many LH pilots do not more than 10 to 15 landings per year, include mixed fleet flying, throw in fatigue, and you have a situation where an airport might be a major threatening variable, if it is out of the normal range, and the sandpit with 40+ temps always is. It is so very easy to get into trouble...:bored:

[411A]

throw in fatigue...

I just knew that 'fatigue' would be brought up by someone.
Lets see, FRA-RUH...yup, sure is a fatiguing sector, alright.:rolleyes:

[DBate]

please consider that many LH pilots do not more than 10 to 15 landings per year, include mixed fleet flying

While this is a fact on the other long range fleets at LH (most of the flights there are enlarged), the average MD11 pilot there averages about 5-8 landings a month...

Still not much, but more than on the other long range fleets.

[DBate]

I just knew that 'fatigue' would be brought up by someone.
Lets see, FRA-RUH...yup, sure is a fatiguing sector, alright.:rolleyes:

I would not be surprised if fatigue was a contributing factor. The flight time FRA-RUH is not very long, but the departure in FRA was in the middle of the night...

[Akali Dal]

SO let's summerize it:

40 deg C on ~2000 feet MSL is "hot an high" airport ??
and should not be used by unwary....?

PS no1. Dubai with sooooo many flights per summer days, even if at ~MSL,
but >50 deg C.....is OK for "unwary pilots" ??

PS no2. In Narita on that day, shall we assume also "hot and high" airport and "unwary" pilots ?

FB and 411A, you two geezers are wasting your time trying to educate these fellas. There are fellas who happen to escape difficult conditions and think they are infallible....tsk, tsk. Well, rarely do you see 50deg C in OMDB and normally the heavy flights avoid operating during the really hot periods. Maybe OKBK will get the above 50deg C days.

[Green Guard]

The flight time FRA-RUH is not very long, but the departure in FRA was in the middle of the night...



and only Owls and Witches should fly in the middle of night, Right ?

PS
one should worry about hot or high or both "hot and high" RWY,
only before T/O.

For Landing the only difference may be longer run...but not limiting factor in this case, Right ?

[DBate]

and only Owls and Witches should fly in the middle of night, Right ?

No, of course not. ;) But taking into account the briefing time prior to the flight and some time for getting to work from home, that might explain the 'fatigue' factor.

My intention was just to point that out. Excluding fatigue as a contributing factor right away seems too easy to me - even if the flight time is rather short for 'long range' flight.
We will all find out, when the final report is released...

Regards,
DBate

[poina]

OERK happens to be the easiest of the 3 major airports in KSA. Much better marked and easier to identify visually than Jeddah. ATC is more professional than JED or DHA.
ILS/DME to 15L/R, ILS/DME to 33L/R, VOR/DME to 15 L/R, VOR/DME to 33L/R.
WX is predominately CAVOK with light winds. Temps high for 6 months a year which do restrict TO weight.
In closing, RUH is an under utilized, well marked, well controlled, airport with 2 3300 meter runways with very little WX. Can you ask for more? What better place to go to especially if crew was unfamiliar.

[Kal Niranjan]

Posted by Green Guard :40 deg C on ~2000 feet MSL is "hot an high" airport ??
and should not be used by unwary....?

PS no1. Dubai with sooooo many flights per summer days, even if at ~MSL,
but >50 deg C.....is OK for "unwary pilots" ??



PS
one should worry about hot or high or both "hot and high" RWY,
only before T/O.

For Landing the only difference may be longer run...but not limiting factor in this case, Right ?

Wow, utter hogwash. DXB has never had temperatures above 50 deg C and I guess someone was sleeping during the met and performance classes.

[oztrekker]

Now, now, Kal give the boy wonder a break....................he is stretching the temp up quite a bit; not too much but it is his understanding about performance and aerodynamics in hot and high airports that's scary!

[golfyankeesierra]

DXB has never had temperatures above 50 deg C
I always understood that over 50 degrees it officially is a hot day and all outside work should be adapted to the heat; not so productive. That's why you'll never see a met report over 50..:E.
There will be enough desert-residents on this forum to correct me if I am wrong.

[VONKLUFFEN]

290 answers to this one . Plus so many for the Fedex in NY and more from the one in Tyo. And how many form the one in HKG? Plus , plus , plus. How many MD11 crashed so far? I lost the count already. All kind of theory about what went wrong. Nothing went wrong. The airplane itself is wrong. When is the authority going to withdraw the airworthiness certificate to this poorly modificated DC 10? Pilots from all around the world have fallen victim to this killer machine. It is not about skills or SOP anymore...

[Flightmech]

VONKLUFFEN

290. Not with you. 3 people lost their lives in the Mandarin crash in HKG. 2 crew in FedEx in NRT and 0 in EWR? Explain?

[TopBunk]

VONKLUFFEN

290. Not with you.

I think he is referring to the number of posts on this thread.

[Spooky 2]

It's interesting that when this aircraft was mostly in passenger service the catastrophic accidents were rare with the exception of the VHHH accident, and Swissair which I can't blame completely on the airframe as opposed to some after introduction IFE. I think lessons learned from the Swissair accident can be appilied across a wide range of current airliners. American, Delta, and a host of other large airlines operated this aircraft without losing a hull. As soon as it started appearing in the freight role the accidents went up. I have no explanation for this other than possible the freighters were operating at higher weights and thus the margin for error was less. I do know that FedEx had a significant numer of tail strikes early in the MD11 introduction. Why them and not AA or DAL, KLM or Swissair?

[bugg smasher]

As the remaining MD-11 aircraft, once having been retired by the likes of FedEx, UPS and LH with their highly experienced training departments, filter down to second and third tier operators (such as the one 411A and others on this forum work for), we will likely see a further spike in accident rates.

[Spooky 2]

So how does FedEx fit into this debacle? They certainly hire experienced avaitors and I assume they have a reasonable trainingg/standards department. I know they probably have more MD11 operations per day than anyone else but I can't get my arms around a definitive problem.

[Flightmech]

TopBunk,

Correct......sorry dumb moment! I was way off:hmm:

[VONKLUFFEN]

:ok: , dont worry Top is like making a Go Around because one stayed to high. Better try again.

Agree is not the pilots, something is damm wrong with this airplane...

[Green Guard]

Agree is not the pilots, something is damm wrong with this airplane...

If you scared from wolves do not go in the forest.

[ipohmali]

I always understood that over 50 degrees it officially is a hot day and all outside work should be adapted to the heat; not so productive. That's why you'll never see a met report over 50..http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/evil.gif.


Hey, you don't need anybody out in the heat to get the temp.....it is temperature in the shade taken by some temperature gauge or probe. Maybe the shady place is at 6 o'clock where the sun doesn't shine!:ok:

[VONKLUFFEN]

:{ Green dont it take out of context. It is not the wolfs nor the forest that scare me. It's the darkness , not able to see, what makes the scenario :} scary.

[Green Guard]

you may be right. Let's wait...

[wingview]

@VONKLUFFEN and others;

Did you realize that all accidents happend manually? There has not been one single accident with auto land. The aircaft is save, just less forgiven in a bounche.

[Neptunus Rex]

wingview
You are probably correct. That being the case, when we can convince every airport in the world to install the necessary ILS equipment with commensurate pavement length, then convince all the airlines to invest in autoland capable aircraft, then give their crews the requisite additional simulator training every six months, plus on-line recency autolands, we might just see a very small percentage reduction in the accident rate.
Most pilots would approve, now go and talk to the beancounters, then ask 411A!
Finally, just as an example, try to design an autoland procedure for Kathmandu.

[MPH]

:D
Maybe all MD11 landings should be autolands then......where the can I mean!!!

[Huck]

MD11 autoland's headwind and crosswind limits are 25 knots.

What do you propose to do when those limits are exceeded?

[Spooky 2]

Is that 25Kts..period or just when weather is predicated on using the autoland? I forget?

[SMT Member]

What do you propose to do when those limits are exceeded?

The same, I suppose, as you would in any other weather situations that excludes you from landing at your intended destination: Divert to alternate.

Making auto-lands mandatory is not, in my opinion, a viable option. The x-wind limitations is just one example; excessive operational limits on legal destinations and alternates would be another. Besides, if an aircraft is classified as only being "safe" to land automatically, then there's something fundamentally wrong somewhere.

To my knowledge that is not the case of the MD-11, and no incident report has even suggested such a thing either. From what I've learned, all landing accidents and incidents so far has involved some level of pilot error; from incorrect handling to landing outside weather limits. In other words, if you fly it like the book says it's safe. It might have less of a margain for error, but that doesn't distract from the fact it's safe when operated by the book.

[Huck]

In other words, if you fly it like the book says it's safe. It might have less of a margain for error, but that doesn't distract from the fact it's safe when operated by the book.

True, unfortunately.

[VONKLUFFEN]

yep MD 11 do not bounce. It brakes, gear, wing, pitches up, down, power, no power , auto throttle , nop, better not here, yep SOP says so mmm ups , what.. what ...GAME OVER. Why? Why SO MANY MD's? . ALL airplanes have the same scenarios, pilots( smart and stupid ones)at the controls, airports, weights , you name it and non of them have the same results the 11's. Less forgiven? That is not an affirmation any CAA or NTSB report would take as valid to justify and incident or accident.
Many have said that the development form DC 10 to MD11 felt short of expectations mainly because the horizontal stabilizer is to small or better said is the same as the one of the DC10. Was that the reason of the implementation of the augmentation, dont know what, system to make the airplane manageable for the pilot? Dunno. The fact is, ALL accidents are SO similar, structural brake up or loss of control during landing. What is the reason?
Hope someone finds out before we hear from a new one...

[MPH]

Vonkluffen. You said it, some ‘smart some stupid’! The stabilizer bit, it´s 30% +- less than the DC10. And yes, manual landing s on this aircraft are done on a daily basis and in pretty adverse weather, wind, etc. So, is this A/C of a bad design or is it just circumstances that dictate the outcome of a landing or is it the handling pilot whom is at fault? I flew this A/C for some 5800hrs. No accidents or incidents related to landing or T/O. 1 engine shut-down( P&W 4060) and maybe a few close RA´s and a couple of bird strikes. For the rest I would say a nice plane to fly. Every beast has it´s different characteristics and has to be managed accordingly! The correct way is a matter of opinion but, the A/C itself, nothing wrong with it!! Just my humble opinion!!:)

[Spooky 2]

MPH, I think you have hit the nail on the head. I agree completely with your assessment. :ok:

[jlreate]

Finnair has flown this plane for a very long time without any issues. I remember reading a farewell article for the MD11 by some chief Finnair pilot (MD11 division) who was praising it very highly.

What were they doing right? Any ex MD11 Finnair pilots around?

[VONKLUFFEN]

MHP your answer in not only :Dhumble but better informed than :rolleyes:mine as well. I'm just trying to :{understand the phenomena. Hope you can give us further :ok:insights since you have more time on the frame than my grandma taking care of her :grandchildren. And let me tell you she does it :Ogreat. I call that experience...:ok:

[MPH]

VONKLUFFEN. Difficult to answer! Training and experience don´t always go hand in hand. If, a well trained pilot does not have the experience under certain curumstances then, his or her reaction might just be the wrong option at that moment. Blaming the A/C is not the problem? As I said, most planes have diffrent caracteristics and as such, you will have to learn the right way to handle them and adapt accordingly. In general terms, under training a pilot should be able to iron out all these isues? Accidents can happen and will happen. Everyone of them has a cause, could be teck, weather,human error, etc. System faults have been related to some of them but, flight caracteristics (civil), few. The Sioux City accident showed up as a system (design) fault. But ,it flew and under the very able hands of an experienced crew was able to land, albeit a crash landing. But, demonstrated that the plane was noble enough to be flown in a very difficult situation. This crew I am sure, never practiced this scenario in a SIM. It was their experience and ability that got them through. This of course with the tragic outcome for a number of pax but, saved the lives of the majority. Hope this gives you some insight and more time with Granny!!!

[DBate]

If, a well trained pilot does not have the experience under certain curumstances then, his or her reaction might just be the wrong option at that momentand
In general terms, under training a pilot should be able to iron out all these isues?Whilst I totally agree with your statement, I found it very interesting ans surprising to read the following:

In a landmark study, Flight Experience and the Likelihood of U.S. Naval Aircraft Mishaps (1992), researches found, that 'pilots with less than 500 flight hours in model (of aircraft) were at a significantly greater risk for pilot errormishap factors' (Yacovone et al. 1992). Interestingly, the study found no correlation between total flight hours and accident rates, indicating that aviatior transitioning to new aircraf are at increased risk as well as pilots who are checking out in ther first aircraft.
Tony Kern, Redefining Airmanship
So, training is for shure one part of the 'defence', but will not be able to 'iron out all the issues'. It seems that even the best and most thorough training will just help up to a certain extend - unfortunately. Experiance on type is needed.

[MPH]

Studi, Agree with the stats. But then if, we look at Russian built A/C you will find that the the hull losses are far higher than western A/C. Pilot or A/C? On the MD11, from the 7 hull loses 5 (hulls) had fatalities. The B720/707 series had a much higher percentage and a few other models had also higer accident rates. The issue, is this A/C unsafe or is pilot handling at fault or what?
In its´defence, I can only say that not only myself, but a very high percentage of MD11 pilots have landed this plane in some pretty adverse WX conditions. Auto lands great... manual with WX you will have to be on your toes. But, I suppose this true of all A/C. Still this plane in my humble opinion is a joy to fly. Not the best I have flown, but preformance wise and system wise, good. Not that many built and a lot in cargo config. Higher weights, yes, higher app/lndg speeds, yes higher AOA on approach yes. This does not make it more difficult to fly, just that you will have to be a bit more alert. Anyway the good old bird is not made anymore, let´s see what the final stat´s are when it´s finaly retired?

[Jetney]

Every beast has it´s different characteristics and has to be managed accordingly! The correct way is a matter of opinion but, the A/C itself, nothing wrong with it!! Just my humble opinion!!http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/smile.gif

So, training is for shure one part of the 'defence', but will not be able to 'iron out all the issues'. It seems that even the best and most thorough training will just help up to a certain extend - unfortunately. Experiance on type is needed

This is the point that Frenk Boreman was trying to make in his post :


I have several thousands of MD-11 hours and all this talk of the aircraft needing an above average pilot to fly is pure nonsense. This aircraft has its unique characteristics, higher landing speeds, smaller tailplane etc....well, an average pilot adapts. If one transitions from DC-10 to the MD-11, you will understand the differnt handling characteristics and handling qualities. You adapt to that and learn to " feel " how the aircraft behaves on final approach, then prepare to adapt to its handling qualities. On hot, humid days on a high elevation airfield one has to really " feel " the aircraft and be prepared for high sink rates. Trying to fly the MD-11 like any of your previous aircrafts will be inviting disaster... it does not need an above average pilot, it needs an MD-11 pilot!

The same thing when I hear of people likening a B77 to a souped up B767...it is not, the high lift wing and triple bogey undercarriage presents different handling characteristics in strong gusty crosswinds on hot and humid days. Guys, know your aircraft. I knew mine and I survived. I am an average pilot and had my share of crunchers...but I survived.


Some people say statistics do not lie, but they can be skewed by whole lot of other factors. The MD-11 is challenging in some ways but I believe a trained and sufficiently experienced MD-11 pilot of average skills will be up to the challenge. Hot and high elevation airports do present environmental factors affecting not only the landing distance but also handling qualities for which the MD-11 may not be so forgiving.

[Huck]

In a year or two Boeing will roll out the 777 BCF (pax to freighter) conversion.

Then we'll have older, converted 777's flying around at max gross, on the back side of the clock.

Then we can make a true comparison....

[Spooky 2]

Does FedEx typically bulk out or gross out first?

[Huck]

Gross, on the longer legs.

All that fuel, you see....

[stilton]

Saying that Autolands will cure the problem is wrong for many reasons.



Of course if the winds exceed autoland limits, what do you do, or what if your Autoland is not working that day / night /



It also assumes that Autoland is infallible. It was not with me one day.



Approaching our destination we discovered the Airport weather required us to
perform a monitored approach with Autoland. Although the visibility was good enough for us to be able to see the runway at Alert height.




This runway does have a downslope when arriving from the direction we were but is approved for CAT111B.



The Approach was flown well, on Autopilot, after becoming visual we could see the runway clearly. The flare was initiated and the power went to idle.



The aircraft then continued to float at, I estimate 1-2 feet above the runway as the runway 'fell away' with the downslope for much longer than I was comfortable with and did not appear it was going to touch down within the landing zone.



I disconnected the Autopilot and gently pushed over placing the mains firmly on the runway, with max reverse and medium braking stopping was not a problem.



My point is, but for human intervention the Aircraft would have happily held that 1-2 feet above the runway until there was none left.



I suggest, that while for the most part Autoland is very useful it is not perfect and I am sure many other Pilots have had to 'intervene' with it over the years when things don't go as planned.



You don't hear about those interventions though.

[iceman50]

Stilton

Don't know how it would have continued at 1 - 2 ft until there was NO runway left, if the thrust was at idle, unless it was a very steep slope!;)

[stilton]

Good point Iceman and no, the slope was not that steep, however the Aircraft in question (B757) has a very high lift wing and will keep flying a lot longer than most.



While it may have touched down eventually, at the rate it was going it would not have been in time to stop before the end of the runway.

[casablanca]

Personally I have a lot of time in MD11 pax aircraft with max landing weights at 458000 lbs and also in Freighter configuration at 491500 lbs.
I think most MD11 pilots will happily land this at max weight vs doing a freighter ferry flight at say 280,000 lbs. With all the mass and momentum it is a pretty true airplane although you definitely have higher speeds and sink rates. When light it is a handful and much harder to get a good landing.
I dont claim to be an aerodynamic expert but for whatever reason the position of spoilers in relation to wing the plane (DC-10 as well) has a noticeable pitch up on landing.....Most of the time we are programed to try and push over and get the nose down, which is the exact opposite of what should be done in an actual bounce.
Like any aircraft after a bounce maintain somewhat of the same landing attitude and possibly add power to control descent if needed.
Most of the MD-11 serious accidents all originated from a bounce---thereafter the wing was unloaded with a large push over....the airplane doesnt seem to like that.

[protect essential]

Surprised by the continuing MD-11 thrashing/questioning. It's not a voodo airplane.

It's just an airplane. Like all the others. Remember the basics, prioritize the killer items, and all will be well.

[411A]

Surprised by the continuing MD-11 thrashing/questioning.
I'm not.
Unfortunately, PPRuNe these days seems to be dominated by non-pilots and very junior pilots, who, upon closer examination...don't know very much about large heavy jet transport airplanes and their successful operation.:yuk:

[three eighty]

Unfortunately, PPRuNe these days seems to be dominated by...

Says he with 8000 posts

[henra]

Surprised by the continuing MD-11 thrashing/questioning.


I'm not surprised either.
Just check the stats against the largely comparable 777/A340 or the 744 and draw your own conclusions.

It's surely not voodoo. It has its shortcomings like all technical objects do. The only question is what effects the shortcomings have. Unfortunately it appears that the effects of its not so good aspects tend to be more severe/less forgiving than for most other contemporary types.

To put it in perspective:
In a world where accidents of large transport aircraft are not considered acceptable at any rate any more an aircraft with an accident statistic which is in absolute terms still quite good (compare it to B707/DC-8 or even propliners) will be quickly considered 'unsafe'.

[Willie Everlearn]

casablanca

I don't think suggesting you add power after a bounce to reduce the sink rate is wise. Adding power to salvage a bad landing will only increase the landing distance and could set you up for another surprise when your thought process is already fuctup following the bounce.
Who taught you that?
Try reviewing the DC-10 overrun in KBOS in the 70s. We learned long ago, Go Around! Simpler, safer and one of the most practiced maneuvers in our pilot careers second only to the senseless V1 cut.

If you fly it, you already know the MD-11 has some nasty, nasty CofG landing habits.

[protect essential]

HENRA, Willie Everlearn.

Just curious. have either of you ever flown the MD-11?

I spent many happy years on this airplane and I never experienced any quirky handling traits.

[Willie Everlearn]

protect essential

Yes I have. Fantastic machine. (with some nasty habits for those asleep at the switch or who haven't yet experienced them)

[casablanca]

I have flown the airplane for 10 years now....not really suggesting the add power vs going around either...that airplane makes most runways look small or minimal. My main point was "dont unload the wing" by pushing the nose down.
The BOS overrun? Are you referring to the World DC-10 that went out into the harbor? That was primarily due to braking action nil....which was not reported beforehand.

[Willie Everlearn]

casablanca

I think I've misunderstood your comment and so I do apologize if you took it as an afront. My having only just read that the LH MD11 hit the runway hard on initial touchdown, and the following three successive touchdowns were progressively harder resulting in...well we know the rest.

It is recommended by Boeing that following a hard landing the crew should execute a go-around. I don't believe this is "the revelation", but believing all MD11 crews would be aware of that, my first reaction was who's teaching the addition of power to reduce sink rate following a hard landing? Yikes!!

I didn't mean to come across as the prophet of aviation. I'm anything but.
The first time I landed an MD11, I pulled all three into reverse and was surprised by the sudden and immediate raising of the nose despite being warned. From that day onward I've held the belief that this tendancy could easily lead to disaster. Why? Because you have to work around the tendancy.

Is that something we as pilots like to see in our aircraft?
I personally don't think it is.

Otherwise, it's a fantastic machine.

I recall vaguely the World one, but it seems to me there was another speed related incident at KBOS. Alitalia? SAS? I'll have to do some more research.

[JEP]

SAS overran at JFK.

Autothrottle INOP and poor speed control, IIRC

[hptaccv]

imho, pitch handling on landing can be tricky - depending on CG, Weight, spoiler & reverse deployment.
Every once in a while this may produce a suprising pitch up moment. Add to this the fact that the MD11 is -imho- imbalanced in the sense that the pitch axis is starkly more sensitive than roll.
Nothing a regular MD11 Pilot shouldn't be able to handle though.

[JW411]

I have stayed out of this so far for I do not have a dog in the fight.

However, some of you are dragging up DC-10 happenings which are completely irrelevant to this thread, which I CAN comment upon.

One of my good friends (PL) overran the runway on landing at KBOS in DC-10-30 N113WA on 23 Jan 1982. The cockpit ended up in shallow water but all of the occupants got off with little or no injuries.

My friend was completely exonerated at the subsequent board of inquiry. The braking action on the runway in question was actually 'nil' but no mention of this was ever passed to the crew by ATC or was even mentioned on the ATIS.

What on earth does this have to do with a heavy landing by a LH MD-11 in Saudi Arabia?

Let us fast-forward to February 1984. I was landing at JFK (in a DC-10). It was a foul day with bad weather, lots of turbulence and lots of precipitation. Everyone had been holding for around 40 minutes in pretty miserable conditions.

I landed on a very wet runway 04R. Because of the conditions, I used 50 flap (normally 35 flap) and cancelled auto pilot and auto-throttle (which tended to prolong the flare). I touched down on the numbers at the correct speed and made a normal landing.

The next aircraft to land was an SAS DC-10 (who had been 1,000 feet above us in the hold). Despite the conditions, they elected to make a 35 flap landing with the auto throttles engaged and didn't touch down until halfway down the runway (this I got from our FAA inspector) and they ended up with the cockpit in Jamaica Bay. (The aircraft was bought and rebuilt by FedEx).

What on earth does this have to do with a heavy landing by LH MD-11 in Saudi Arabia?

Absolutely nothing.

So why on earth do you experts keep spouting stuff that is completely irrelevant to the discussion and about which you know less than nothing?

[Flightmech]

JW411,

Agree, any DC-10 incidents are completely irrelevent.

However, since you bought up that SAS incident at JFK, the airframe is now N311FE, now converted to an MD-10 and was affectionately known in the company as "The Salty Dog" after it's entry into the bay!

[wozzo]

Safety Recommendation (PDF) (http://www.ntsb.gov/doclib/recletters/2011/A-11-068-069.pdf)

Accident narrative

The first officer reported that he sensed that the airplane’s sink rate was increasing at
80 feet, but he retarded the thrust levers at 50 feet, in accordance with Lufthansa Cargo standard
procedure. He did not attempt to advance the thrust levers before touchdown. The first officer
stated that he believed he had started the flare at 30 to 40 feet, but recorded flight data showed
that a pull on the control column was initiated between 15 and 30 feet agl, at which time the sink
rate decreased only slightly, to about 780 feet per minute.

The cockpit voice recorder captured, at 10 foot intervals, automated aural announcements
from 50 feet to initial touchdown that did not decrease in frequency as would be expected during
a normal flare as the airplane approached the ground. The captain, who was the pilot monitoring,
did not call out the high sink rate or call for a go-around, as suggested in the Lufthansa Cargo
Operating Manual. The captain later reported that, for a split second, he thought the first officer
should flare but that he was satisfied when the first officer did flare. The captain said that he
could not take action in time before the touchdown, which was measured at 2.1 G.

Following the initial touchdown, the aircraft bounced about 4.7 feet off the runway and
the nosewheel touched down a second time at 3.0 G. After the second touchdown, the aircraft
reached a pitch attitude of 13°, and a third touchdown, on the main gear, exceeded 4 G. Flight
data indicated that two large forward and aft control column inputs were made between the first
touchdown and the third and final touchdown.

Reporting his recollection of events after the initial touchdown, the first officer described
the nose as “coming up and down” and said he did not have a clear recollection of what
happened after that. The captain stated that “what came after touchdown was shocking” and
“much beyond [his] experience.” He said that strong movement of the nose was unexpected and
that the pitch attitude was higher than the maximum allowable and outside of his comfort zone.

LH "Bounced Landing" Training

According to the captain, he had not completed the company’s “Bounced Landing
Recovery Procedure” training, but he had been trained to maintain 7.5º of pitch when recovering
from a bounced landing. The first officer had completed the bounced landing recovery training
along with his initial training in 2010. A one-time course, Lufthansa Cargo’s bounced landing
recovery training was developed based on the company’s experiences with hard landings, as well
as those of other MD-11 operators. During the simulator session, an instructor demonstrates a
hard landing and the trainee takes control, maintains 7.5º of pitch, and applies go-around thrust
to recover. The company’s MD-11 chief flight instructor stated that the simulator was limited in
its ability to capture the true sensation of a bounced landing, and the head of flight operations
said that, while bounced landing training was positive training, it may still be difficult for a pilot
to recognize a bounce in a real aircraft.

High sink rates & pitch control

Although it is not uncommon for jet transport aircraft to experience a small skip or
bounce during landing, since it was entered into service in 1990, the MD-11 has had at least
14 events of such severity that the aircraft sustained substantial damage, including 4 events that
were complete hull losses (see table). Seven of these events have taken place in the last 2 years.
The number and severity of these events raise concerns that MD-11 flight crews are not
effectively trained to recognize and arrest high sink rates during landing or to properly control
pitch attitude following a hard landing.

Recommendation

Require Boeing to revise its MD-11 Flight Crew Operating Manual to
reemphasize high sink rate awareness during landing, the importance of
momentarily maintaining landing pitch attitude after touchdown and using proper
pitch attitude and power to cushion excess sink rate in the flare, and to go around
in the event of a bounced landing. (A-11-68)

Once Boeing has completed the revision of its MD-11 Flight Crew Operating
Manual as recommended in Safety Recommendation A-11-68, require all MD-11
operators to incorporate the Boeing-recommended bounce recognition and
recovery procedure in their operating manuals and in recurrent simulator training.
(A-11-69)

[Denti]

Seems the report is out according to AvHerald (http://avherald.com/h?article=42edca16/0001&opt=0). However i it says it is released via the german BFU, couldn't find it on their webpage though.

[John Marsh]

Click here (http://www.bfu-web.de/cln_030/nn_223936/EN/Publications/Investigation_20Report/2010/Report__10__2X003__MD11__Riyadh,templateId=raw,property=publ icationFile.pdf/Report_10_2X003_MD11_Riyadh.pdf)

[Denti]

Thanks for the link.

[Cyrano]

Why on earth have they redacted the name of the operator throughout the report? :confused: It's not as though it's a secret.

[SMT Member]

In essence: FO late on the round out, a 2.0G hard landing startles the skipper who - sitting in a descending cockpit - made a large FWD control input, but the main-gear had already bounced and the aircraft was climbing aft of CoG. Spoilers up at 30deg following wheel spin-up. Second flat bounce at 3.0G, main- and nose-gears, spoilers deploy to 60deg due gear compression. Both pilots pull back and after reaching a ridiculous AoA the last 4.0G impact results in structural failure aft of the wings. Skids off, crew evacuates - FO with back injuries.

Uncharactaristic for an MD-11, in such a situation, not to have a main-gear plow through a wing with catastrophic spar failure as a result. They're lucky to have walked away.

Report suggest, among other things of course, Boeing rewrite the manual on recovery from bounced landing.

[Sqwak7700]

Really lucky they did not end up like FDX at Narita, just pure luck.

I can't believe that 10ft difference in flare height is enough to total an airframe. Most jets only give you a firm landing if you flare a bit late. And if you carry a bit extra speed crossing the threshold, many will give you a greaser.

I wonder what else is behind the trickiness in the MD-11. It can't just be the crews when so many have made the same mistake with similar consequences. :confused:

[Gretchenfrage]

I said it a million times already:

The MD11 is not tricky in the real sense of the word. It just needs good pilots who can deliver stable final approaches.

The speed/drag curve is climbing sharply behind Va and one should never get below that reference. But this should be trivial for a professional. That it is not, originates in the new training methods and shortcuts. Many pilots are routed through aircraft that no longer really need pitch and power discipline. They are told that if in trouble, to let go of the stick/yoke and most certainly not to interfere with the holy thrust levers, automation should take care of it! It takes away the pilots' awareness of impending speed loss, of what a increasing attitude may warn of, that chasing the flight director may please a TRE in the sim and all the sops, but is detrimental to stable short finals if you weren't established throughout the approach beforehand.

What surprises me is not the fact that we might be discussing such accidents, but the lack of honest awareness of why they happen.

[Huck]

Many pilots are routed through aircraft that no longer really need pitch and power discipline.

That's it.

[Hotel Tango]

Not a professional input but just a simple observation - and a lesson to all our "expert" PPRuNe air accident experts: There was no emergency declared nor an on-board fire prior to the accident!

[Ramrise]

Gents,

Anybody know how the first officer is doing these days??

[Geardownandlocked]

The first officer, after a recovery period, is flying for the company again.

[Vc10Tail]

I noticed LH cargo carries a lot of rather junior looking First Officers.Is it for some their first type rating?

For normal flying carying inexperienced FOs as handling pilots shouldn't be an issue.When the maneoure hits the turbo fan!!!!!....these heavy jets become a handful even for the most experienced F.O.s I saw one video IN U tube of an Alitalia MD11 landing in Hong Kong...what looked like a normal stabilized approach suddenly ...like a viper bite..snapped at the co-pilot's hands (and he seemed experienced) and the juggernaut snapped into a dangerous attitude...much to the Captain's chagrin who was left barking like a mad dog! :}
I have witnessed both LH Cargo and Swiss in Nairobi doing some pretty unstabilizing (to the onlookers eyes :rolleyes:) tango manoeuvres at below 300 feet!I haven't flown these monstrous tri-jets except on simulator (Tristar and DC-10 63).I have noticed in sim that they tend to just want to drop if you let them slide behind the min drag speed point...and without a generous pitch and thrust...you would be doomed:eek:

[lexxie747]

vc 10 tail?
DC-10-63?

[Vc10Tail]

That was the first 747 crash.It was in Nairobi (1973-75?).Leading edge flaps were forgotten to be deployed..due to a taxi procedure to isolate some switch.Since then the flight control surface position indicators were designed and installed in all Boeings of that generation...which trickled down to the 732!

[Vc10Tail]

What about them??:confused:

[Zorin_75]

What about them?? Has never been built.

[golfyankeesierra]

dc10-63
found some parts in the Mojave and put all four DC-8-63 engines on the back of a DC-10-30 airframe and voila: a sort of VC-10
(only better looking then the real one :8 )

[golfyankeesierra]

That was the first 747 crash.It was in Nairobi (1973-75?)
What about it?
Was it also because of some under-qualified F/O? It certainly wasn't one of your "monstrous tri-jets" (you do seem to mix up your types a little bit).


BTW
I haven't flown these monstrous tri-jets except on simulator (Tristar and DC-10 63)
Is it just bad grammar or do you really mean that besides the MD-11 you consider the DC-10 and L1011 monstrous as well :=?
There's somebody turning in his grave :}

[PJ2]

Sqwak7700;

Re, "I can't believe that 10ft difference in flare height is enough to total an airframe. Most jets only give you a firm landing if you flare a bit late. And if you carry a bit extra speed crossing the threshold, many will give you a greaser. "

Trying to clarify here...I don't think it was a "10ft difference in flare height" that was "enough to total an airframe". From the Saudi Report:

4. The Captain attempted to take control of the aircraft without alerting the First Officer resulting in both flight crews acting simultaneously on the control column.

5. During the first bounce, the Captain made an inappropriate, large nose-down column input that resulted in the second bounce and a hard landing in a flat pitch attitude.

6. The flight crew responded to the bounces by using exaggerated control inputs.

To me this sounds more like PIO than it does a late flare. As others have pointed out, the screenshots from the airport security camera showing the initial touchdown, bounce, nose-high then flat touchdown certainly look like Narita.

I haven't flown the type but from what those who have have observed the airplane may require stricter control of pitch and power but is otherwise normal. A disciplined approach to pitch and power has been mentioned before regarding this design including bounced-landing training. Messing with pitch control after a bounce is, I think, asking for trouble in any airplane, the SOP generally being a go-around but surprise and "focus on the mission" when things are happening rapidly....etc

[casablanca]

All of these MD-11 crashes had a firm touchdown and bounce but disaster seems to follow what happens next...large forward and aft control column inputs.

[PJ2]

My point, and what I'm wondering is, if the (instant) decision is to say on the runway and not go-around, and if the control column inputs remain neutral, will the MD11 still behave the same way in pitch. In other words, is the airplane pitch-unstable in a bounce or is the instability a result of control inputs, small or large? If one freezes the control column and waits for the next touchdown, will the airplane behave as we have seen or is this sufficient to stabilize the landing such that its "normal"? Bear in mind the crew did not recognize that the aircraft had bounced.

[Vc10Tail]

Hey...Mr.Perfect...haven't you made a syntax error in your life?You are only publicising your childish mentality by writing what you wrote.

I stand corrected..the DC-63 never got built, but there were plans for it with RR engines and B.A. had expressed interest.I meant DC-10 series 10,30 and 40...IF THAT WILL SATISFY your bloody mindedness.Yes we do know that DC-8 had a series 63, and perhaps with an engine transfer on the DC-10 you would be the ace test pilot to fly it...and use the other spare engine as its APU stuck aptly...in YOUR tail!:rolleyes:

[Vc10Tail]

The MD-11 was designed with a smaller horizontal stabilizer than other airliners. That, plus the shifting of its center of gravity further aft, all to reduce drag and thus fuel burn, causes it to be unusually light on the controls. That design, known as “relaxed stability,” is common to fighter planes but is not normally found in the pitch axis of a civilian airliner. It makes it more likely that the pilot will overcontrol during an upset recovery.
1994, November 4. A Fed Ex MD-11 freighter made a hard landing, and a tail strike at the Anchorage, Alaska airport. After selecting 50 degrees of flaps the first officer, who was flying the plane, was not able to stabilize the approach in the pitch mode. The attitude of the plane varied approximately 2 degrees with corresponding elevator position changes. The captain, because of the high sink rate, grabbed the yoke and pulled back. The plane landed hard, bounced, and oscillated at least three times, reaching a maximum pitch up attitude of 12.3 degrees. The tail struck the runway during the oscillations. This was also the plane that crashed at Newark in 1997.
1996, May 16. A Fed Ex MD-11 freighter encountered wake turbulence from a preceding 747 as it was landing at the Anchorage, Alaska airport and suffered substantial damage. When the plane entered a high sink rate, the captain tried to go-around but the lower aft fuselage hit the runway and bounced. The captain discontinued the go-around and the plane bounced two more times, causing substantial damage to the aft pressure bulkhead.
Prior to this accident, Fed Ex did not have formal tailstrike awareness training for its MD-11 pilots. After this accident, however, Fed Ex developed a tail strike awareness training program that included bounced landing recovery in its simulator training. That program limited pitch attitude to 7-1/2 deg for recovery from a bounced landing.
1997, June. Thirteen people were seriously injured when a Japan Airlines MD-11 experienced severe pitch oscillations. One passenger went into a coma and died, 20 months later.
The pilot attempted manual recovery when the autopilot failed to detect the plane was flying too fast after an encounter with wind shear. The pilot’s repeated attempts to stabilize the altitude caused the severe oscillations that injured passengers and crew. The autopilot was blamed for the accident because it contained a programming design defect that commanded it to respond to average velocity calculations instead of actual speeds.
1997, July 31. A Fed Ex MD-11 bounced on landing at Newark airport and then flipped upside down off runway 22 R. The two pilots and three passengers managed to escape before the plane was destroyed by fire. The investigation is focusing on the failure of the right main gear, which allowed the right engine and wing to dig into the ground, flipping the plane over.



Wreckage of the Fed Ex Newark accident, July 31, 1997

There is now some question about the structural strength of the wing box; whether it was strong enough to absorb loads that were well within the spar’s limits. If it wasn’t as strong as it should have been, the next question will concern the same structures on other MD-11s. Are they deficient too, or was it just a defect in the manufacture of that particular one? The same plane had been involved in two other hard landing incidents, prior to this accident. They are also examining the possibility of the pilot overcontrolling as he tried to correct after the first bounce.
It is obvious that Michael Crichton’s 1996 novel, AIRFRAME, is based on the checkered history of the MD-11, and in particular, on the deficient designs of its slats and pitch stability systems. Crichton’s N-22 (his fictitious name for the MD-11) comes out as a stellar airplane that suffers only from bad press. Likewise for the DC-10. His discussion of the misfortunes of the DC-10 (beginning on page 181, in the paperback edition) is greatly distorted, chiefly by what he leaves out of the discussion. In my view, the DC-10 is one of the worst designed airplanes to ever come down the pike and the MD-11 is not much better.
1998, September 2. A Swissair MD-11 plunged into the Atlantic Ocean, with the loss of all 229 onboard, after the pilots reported smoke in the cockpit. That investigation is ongoing and they now have evidence of a fire fore and aft of the cockpit bulkhead. Recovered parts, from the cockpit area, included a portion of the sheepskin cover from the F/O’s seat, an armrest, air filter, melted aluminum, electrical wires with melted copper, charred or missing wire insulation, and smaller parts that were discolored by heat. Those parts are undergoing analysis to determine the temperature levels and heated gases to which they were exposed, according to the TSB (Transportation Safety Board of Canada). That accident has prompted many questions received at this web site.
1999, August 22. A China Airlines MD-11 crashed while landing at Hong Kong’s Chek Lap Kok airport, during a rain storm with strong, gusting crosswinds. The right gear struck the runway very hard and then broke off, allowing the right engine and wing to strike the ground. The right wing then broke off and the plane flipped upside down. That is very similar to the type of damage incurred by the Fed Ex MD-11, when it crashed at Newark. Three of the 315 people on board Flight C1642 were killed. The rest owe their lives to the Hong Kong airport’s fire brigade that put out the fire before it engulfed those trapped in the wreckage. It took almost 3 hours to remove all the survivors.


Failure of the wings, in the area of the fuselage attach points, has called into question the structural integrity of the wing box structure of the MD-11 and is part of the focus of investigation in both accidents.
It was the same plane that was involved in the turbulence accident on Dec. 7, 1992, described above.
1999, October 17. A Fed Ex MD-11 touched down at Subic Bay, in the Philippines and then ran off the end of the runway and sunk in Subic Bay. The plane was a total loss, but the 2 pilots escaped with only minor injuries. The report found the probable cause to be:
The failure of the flight crew to properly address an erroneous airspeed indication during descent and landing, their failure to verify and select the correct airspeed by checking the standby airspeed indicator, and their failure to execute a missed approach. These failures led to an excessive approach and landing speed that resulted in a runway overshoot. Contributing factors to the accident were clogged pitot tube drain holes, the MD-11's insufficient alerting system for airspeed anomalies, and the failure of the SEL ELEV FEEL MAN and SEL FLAP LIM OVR D checklists to refer the crew to the standby airspeed indicator.


Fed Ex, Subic Bay. The pilots were very lucky to escape this accident with their lives. It would have been a much different story if the plane had been packed with 300 passengers.........

2001, November 20. An Eva Air MD-11 made a hard landing at Taipei, Taiwan. The first officer was flying the plane as it hit hard and bounced. The captain immediately took control and initiated a successful go-around. After the second landing, investigation revealed substantial damage to the nose wheel well structure and one of the two nose tires had failed.

[PJ2]

Gentlemen, if we could please re-focus on the airplane and its characteristics...?

Does anyone have the current FCOM "Bounced Landing" procedure and can they reproduce it here? I'm curious about what it requires the crew to do. Is the FCOM response a go-around or does it permit the crew to control the pitching? Are there two responses (either go-around or try to control pitch) depending upon the firmness of the landing? (I ask, because it seems to me that a high bounce in all transport aircraft requires a go-around whereas a smaller bounce, (I realize the Saudi report says this one bounced only 4ft) may be recovered using pitch inputs even if that means freezing the position of the stick until after the second touchdown).

The airplane exhibits behaviours that other aircraft with a more forward CofG do not. I'm curious what the FCOM has to say about this.

The more I think about the MD11, the more I think it is prone to pitch instability in comparison to other similar-sized transports and that even leaving the stick alone "frozen" for a moment in one position may not assist recovery from a bounce, which does lead a pilot into a PIO-like response.

Yet those who fly the aircraft say it is for all intents and purposes, "normal".

For those that fly the airplane, can you compare the control column motions with other types you've flown, once landing flap is selected? Are you "busier"?

[Gretchenfrage]

The witch hunt continues.

Let me just point out that no DC10 or MD11 was ever lost on a test/demonstration flight or by high level upsets ..... so the actual discussion seems to me like a naive diversion!

The mentioned instability inflight on MD11s only happens in cruise with fuel balance control, fuel to the aft tank. In approach configuration the aircraft has a trim characteristic as others, no more fuel aft.

The bounce recovery is mentioned as leaving ~7deg pitch and no longer attempt to land but go around, again quite similar to other aircraft.
Attempting to land with power to idle, spoilers deployed, rebounced to 20' and attitude to 6deg, by pushing onto the nose wheel sort of points to inadequate pilot technique and decision making, but not very much to aircraft design.

There is a tendency for PIO after a bounce or unstable approach, agreed, but never to the unsafe extent. MD later implemented push and pull limiters in the full configured state to mitigate this arising problem. To me this was the wrong approach, chosen because less trained pilots started flying the bird. They should have left the full authority and demand increased training/skills for the MD11 pilots.

The mushiness described in full configuration is only a consequence of lower speeds. The sops of setting Fl50 and refraining from using the equally normal Fl40 setting which gives more and better authority, was detrimental. The widespread fright by MD11 pilots about its high Va and the not very sensational braking characteristics, made them adopt the Fl50 and fly the Va to the lowest limit, some even going into Vthreshld (Va-5). All this gives a somewhat mushier experience compared to a Fl40, Va before-flare speed.
A sop and training item to me.

It is a fact that the LSAS (castrated longitudinal fly by wire, compared to the CWS of the DC10) is less agreeable to fly and should not be deactivated, as the CWS could be, for landing. This is a design flaw. MD should have left the beautiful CWS.

As for the wing box design, leave it to engineers to decide, to me it's stable enough to withhold "normal" hard landings.
Otherwise we could start building tanks that withhold crashes ....

Let me finish my remarks with branding anyone a complete moron who brings in the Swissair tragedy in conjunction with MD11 design.

[stilton]

'Let me just point out that no DC10 or MD11 was ever lost on a test/demonstration flight or by high level upsets ..... so the actual discussion seems to me like a naive diversion!'



So its perfectly forgiving in the hands of an experienced Test Pilot.



Impressive..

[Gretchenfrage]

So its perfectly forgiving in the hands of an experienced Test Pilot.

unlike a certain A333

Impressive ...

But I don't want to get into a slugging match. The MD11 is as dangerous or not as modern competitors. Untrained or bad pilots crash any one of those.
Maybe some models need more training when in upsets, the MD11 needs more for the final approach.

What do you prefer, what is more easy to handle??

[DOVES]

Sirs
I have flown the MD11 from 1994 to year 2000, and for two different airlines.
I’ll try to summarize my experience with her. Landing that beast is tricky from 50’ down.
At that point the autothrottle begins gradually to retard the engines to idle. This means that the flare, if for any reason the threshold speed was too low, had to be more carefully processed.
That’s the reason why someone developed the habit to disengage the autothrottle in a very short final and to manually retard the engines to idle when needed.
The second deception comes when the main wheels spin up. At that moment the spoiler panels on the wing upper surfaces come up producing an abrupt and strong pitch-up moment.
So: the pilot was exerting a pull force on the control column for the flare, and in a split second he has to revert the effort on the elevator, pushing it down, in order not to contact the tail on the runway.
Now imagine what happens if someone (PF or PNF/Cpt) pushes hard the column forward as usual, but either the aircraft is not yet on the ground (convinced that it is), or it bounced (and the feeling is that the mains are firmly on the ground).
The nose wheel collapses on the land and… We all know the remnant of the story, written so many time.
Those are my two cents.
And I long for someone to correct me.

[Mariner]

I have flown the MD-11 for some 4000 hrs, until 2004. In both passenger and cargo ops.

I enjoyed flying it, but it is an airplane you have to be careful with when landing.

When designing the MD-11, McDonnell Douglas reduced the size of the horizontal stabilizer compared to its predecessor DC-10, for fuel efficiency reasons.
Obviously, this reduced pitch authority to a certain extent. To compensate, LSAS was installed which has been described before. It is basically a horizontal yaw damper with a few additional softwaremodes.
After a number of tail strikes and hard landings, they added a nose-lowering mode to it. It trims the nose down after touchdown. That helped somewhat.

My experience; especially when flaring a bit late, it can surprise you by further pitching up after touchdown. Requiring a good push on the yoke to avoid a tail strike.
During the first few years that my company operated the MD-11, I have seen, and also made :ouch:, nearly full nose down inputs on the yoke, to the stops. I had never seen that on any other airplane before, nor have I seen it since.
Since then, we, the pilots, have learned to deal with this airplane’s peculiarities, and my company has not had any tail strikes or landing accidents. And hopefully it stays that way, as we still operate it. I’m sure luck has played a part in that record.

LH, FX, DL & others that have had MD-11 accidents are professional airlines with carefully selected pilots, and I’m sure they train them properly. So if these airlines have significantly more incidents and accidents with this airplane type and not with others, it must be the airplane that is different. I don’t think there is much doubt about this. The accident statistics speak for themselves.

The smaller horizontal stab gives you somewhat less control, especially at lower speeds with full flaps.
On top of that, I believe the airplane has more longitudinal inertia, due to the tail engine. That heavy engine takes time to start moving up or down.
I also wonder if the gyroscopic effects of that tail engine play a roll in this inertia.
Regardless, it requires more force to make it pitch up or down. Combined with the smaller horizontal stab, it makes pitch changes take longer than you are used to.


Let’s look at the landing.
Assume you flare a bit on the late side. Realizing this, you pull up a bit more than usual. However, due to the longitudinal inertia and smaller stab, this takes longer than you are used to. So you wonder if something is ever going to happen, and pull a bit more. Finally, the airplane begins to react; it will start to pitch up. The mains touch down. But the pitch rate will continue after touchdown due to the longitudinal inertia, added by the pitch up tendency caused by the spoilers. So a good push is needed to avoid a tail strike. Lowering the nose again takes time, perhaps causing more pitch down input than needed. When you finally get a downward pitch rate, you have to stop it again before putting the nose gear through the runway.

This is a perfect recipe up for a PIO, Pilot Induced Oscillation, which is what we have seen on several MD-11 accidents.
Anyone who has flown the MD-11 will recognize it.
This PIO is even more dangerous if you have bounced, and become airborne after the first touchdown. A go around is the only safe recovery out of this situation.
But what if you don’t realize that you bounced? Apparently, that is not as easy as it sounds, because several crews didn’t recognize being airborne again.

I don’t pretend to have an easy solution for this tricky airplane characteristic.

I don’t see a technical solution, because you cannot do anything about that horizontal stab and the tail engine. We are talking about a twenty odd year old airplane here. For Boeing it is a ‘heritance’ model, and I’m sure they would love to get rid of supporting it. They do so hesitantly now. With it's high accident rate, they probable see it as a liability.

Installing HUD's then, as proposed by the Saudi Accident board? I doubt if they would be effective. Things happen quickly during landing, instinctive reflexes take over. Reflexes that were developed on other, more benign, airplanes.

An obvious start would be bounce recognition and recovery procedure training, as several airlines do. Not only during initial-, but also during recurrent training.

Briefing this procedure during every approach briefing would help to reinforce awareness of this tricky airplane behavior.

Experience on the airplane certainly helps, as I did not see full control inputs anymore after those early years. That means that anyone who has fewer than, say, a few years on the airplane has to stay extra vigilant. And the pilot next to him/her as well.

And don’t think twice about going around.
For the mindset, it might help to always take along enough fuel for an - extra - go around (on top of the std 30 mins final reserve). That way going around becomes a bit more carefree.
An extra expense, for sure. But accidents or incidents are more expensive.

I once read a beautiful suggestion on PPRuNe; a bottle of wine each for pilots that made a go around, no questions asked. With compliments, from the MFO. FDM will take care of everything else.

Bottom line; even though the MD-11 is an airplane with certain peculiarities, it can be flown safely by experienced and professional crews.
But be careful landing it. ;)

[Old and Horrified]

Mariner - thanks for a really interesting post.

Slightly off topic, but I have to respond to Vc10tail's comment "In my view, the DC-10 is one of the worst designed airplanes to ever come down the pike".

I thought it was a beautiful aircraft and a delight to fly. However, I may be biased as it was also the last large aircraft I ever flew after Laker went bust almost exactly 30 years ago.

[PJ2]

Gretchenfrage;

Thanks for your input. The discussion I was hoping for and am now seeing was one between professional airline pilots, some of who may have flown the MD11 as I have not.

I am as interested in understanding this airplane as I do the Airbus. I don't wish to get into a push-and-pull regarding types either mainly because questions of complexity are different than questions of stability. The A330 airframe design doesn't have habits which require forgiving but its fbw & level of automation certainly does demand a very high level of understanding and therefore training, just, (as you say), in different areas. To the industry, "training" and even hiring, seem to be areas in which airline CEOs seem to think they can cheapen because "modern airplanes fly themselves", or some such variation on the theme. - another thread!

I have no point of view on the MD11...understanding is not a point of view, but I do have a point of view on the A330 and Airbus because I'd flown them for fifteen years until retirement. I'm very interested in the thoughts of those who have experience on the MD11 and for that reason I do appreciate your posts.

DOVES;

Mi piacere...grazi, (I wish I knew more!). I am hearing similarities with Mariner's post.

Mariner, many thanks for a superb, dispassionate summary. It helps understanding greatly, offering appropriate cautions while respecting the aircraft and the skill of those flying it.

In my reading (both private and here), I sense also that the CofG is a bit further aft than other transports. Coupled with the factors you have described regarding longitudinal inertia etc, that becomes another aspect to be respected.

You mention FDM...has the program helped in terms of addressing these issues, especially for those transitioning to the airplane?

[Gretchenfrage]

PJ, thanks.

Having flown both, I remain quite philosophical.

The MD11 unveiled today's lack of pilot skills. As the industry needed so many jockeys, it showed that there's only a limited number of Topper Harleys, you can dig as deep as you want. The modern airliner needed to be more forgiving to adapt to such fact. The MD11 might just have been slightly over the tolerance.

The fbw Airbus unveiled today's lack of IT and aircraft operating system knowledge. Again, there's only a limited number of Greg Woszniakies, you can did as deep as you want. The modern airliner should therefore be less complex in abnormal situation handling. The Airbus might just be slightly over that tolerance.

Without wanting to judge, or fall into a A-B discussion or lobbyists trap, let me simply state, that being on the T7 now, I am relatively happy. This design is very forgiving on landings and has a more hands on approach on fbw.
(but please fix that damned spoiler!)

[PJ2]

Gretchenfrage, yes, I remain on the philosophical side as well, happy in retirement and doing a little flight safety work on the side. Nor do I desire to lobby...I consider myself deeply fortunate just to have achieved a childhood dream. Sadly not many can say this and I am forever humbled.

As I watched our Navs being replaced with INS, then the first trials of Honeywell's "FMS" (on a B727) and the developments of the L1011 & B767 which initially was built with a panel for the oiler, I never felt that automation was "inevitable" as an operational solution to the problems of flight itself.

But in order to wring maximum mileage and carrying capability per kilo burnt and to reduce crew costs perhaps the "solution" was somewhat inevitable, but certainly not from a human point of view.

It is true that flight safety has been enhanced thereby but I would never believe anyone who may claim that safety was the prime objective in automated flight.

Not only raw flying skills but instrument scan, thinking skills and knowledge of the machine and of aerodynamics of high speed, high altitude flight have all atrophied to the point where fewer and fewer do not know how much they don't know. I've written at length elsewhere about this.

The T7 seems to be a very happy balance. My favourite was the L1011-500 but the A330 was a very fine airplane once one understood autoflight and that usually takes a year or two of hard work. Trouble is, if I may be permitted one small advertisement, the airplane works so well that once the bread-and-butter push-buttony thing is learnt it masks this need for deeper knowledge and some people who fly it get comfortable, then lazy.

[fdr]

MD - Mariner's observations.

Thats a pretty good summation of the MD, mariner; it is an aircraft that requires proficiency.

The original idea to reduce the stabiliser was reasonable given the arm change that occurred with the fuselage extension. Unfortunately, the aircraft also has other "minor changes" that do change the flow conditions of the stabiliser and elevators. (if you want to know what, PM me and I will provide some reference material to indicate what is occurring).

I'm not rated on the MD, but I have done HQ on it, in relation to accident and incident investigation, and a couple of issues were notable. 1, the simulator aero model is very much constrained to normal operational envelope, ie it is anywhere from inconsistent to wildly erroneous as you proceed outside of the normal envelope (these including areas that the operators train within); 2, the aircraft is prone to PIO particularly in high altitude operations without LSAS, but also in the flare; 3, is susceptible to flow related damage when operated outside of the buffet boundary. The machine meets the requirements of the Part, but is arguably on the higher side of nice on the C-H HQ scale. The stick force gradient is normal. (I am testing one non part 25 aircraft at present that has two distinct ranges of static instability, and it was considered by the powers that be to be suitable for fairly low time fodder to fly... it is interesting, but definitely demands care and respect). The Scud has a repeated failure mode of the wing with hard landings, which certainly suggests it be good practice to avoid operations occasioning high isolated wheel ground impacts. Caveat: my experience with the aircraft is a number of years ago, and there have been some beneficial and overdue changes incorporated to the FMGS and other systems.

With all of that, it still is a neat aircraft, and handles nicely enough, but all round, with the high approach speeds that are characteristic of the fleets operation as a freighter coupled with a very simple flap system (nice though), on dark nights, tired crew etc, it is a handful.

Personally, I think that the addition of a HUD is a nice secondary solution to the aircraft's tiger-by-the-tail reputation. The HUD gives a good indication of any increasing sink rate on short final, (CLK dynasty bingle) and also an indication of the initial effectiveness of flare input WRT flight path.

The stability issue and the approach speed are eminently possible to modify, but I doubt that any current user wants to pay for the necessary STC. (The plane is ripe for a reduction in approach speed in the order of 15% with simple modifications, which would also alter the trim condition favourably).

Love the DC/MD's sunroom, great place to enjoy the view from. The systems and automatics otherwise were years ahead of the competition. FWIW, while I really like the MD, I think that the Capt's that give away sectors to low time new crew need to be given medals for valor.

[Huck]

I don’t pretend to have an easy solution for this tricky airplane characteristic.


The B777F.

[Machinbird]

But the pitch rate will continue after touchdown due to the longitudinal inertia, added by the pitch up tendency caused by the spoilers. So a good push is needed to avoid a tail strike..
Being a bit of a systems geek, this bit about the spoilers caught my attention.

Seems to me that the new B748 was found to have a similar tendency during early test flying. The solution was to add a bit of a time delay to the outboard spoilers activation.

[Lyman]

Machinbird

In a long discussion re: Narita, the main spar fractures came up. One cannot help but remember that the design and manufacture of this a/c (MD-11) was the effort of a company that designed another heavy a/c made to plant on the carrier deck.

As a Phantom driver, I'd be interested in your take on the placement of the Main Landing Gear struts directly under and to the Main Wing Spars. The focal energy on the wing is apparent in watching that tragic vid at Narita. Likewise, the Nose Gear remains (undamaged?) after the intense Nose Plant on the final hop.

Given that this a/c lands heavy and with Pitch issues, would some attention paid to sacrificial structures have been indicated in its design/service/survivability?

fdr: just read your note re: hard landings. What do you think of the gearMate?

[Machinbird]

Lyman, you are confusing the right hand and the left hand. The Phantom was designed long before in St Louis by McDonnell only. The MD-11 in Long Beach 20+ years later using a lot of Douglas DC-10 technology.
In any case, substantive modifications to the aircraft in that part of the airframe are likely to cost really big $$$ and cannot be economically justified.

The MD-11 could probably also use a "bounce" warning system with a verbal annunciation of the condition. If it is that hard to tell (in time) that the aircraft has transitioned back to airborne after a firm landing, then something should warn the guys flying. (More systems geek thoughts.:8)

[Prof2MDA]

The key to this accident is in the chart on the last page. The MD-11 does not have anything particularly unique about its handling characteristics. All the stuff about size of the tail, etc., does not hold up when actually analyzed. The "fear factor" has a greater impact on how pilots fly it than anything else.

[Prof2MDA]

Lyman

No. There is not a transport flying that would withstand even half of the forces that have occurred in any of these accidents.

[Huck]

Small point but the struts are underneath the aft wing spars, not the main ones. Result is the same.....

[PJ2]

Prof2MDA:

Re, "All the stuff about size of the tail, etc., does not hold up when actually analyzed. The "fear factor" has a greater impact on how pilots fly it than anything else. "

Who is doing the aeronautical work regarding analysis of the tail?

And speaking of not holding up, where is "fear factor" in the report?

In re the "size of the tail", there are some pretty clear indications from experienced and knowledgeable aviators who, we see, have lots of time on the aircraft and who are, in my view, qualified to make the statements they've made.

Comments regarding the size of the horizontal stabilizer have also been made in private communications.

On the other hand, nothing has been mentioned regarding "fear factor" but instead what has been mentioned is the aircraft's clear demand for competency and training. In this, there is nothing new even as standards are lower today, with increasinly visible results.

[thermostat]

Because of the height of the centre engine on the MD11 (and DC10), the application of reverse thrust is bound to pull the tail down resulting in a nose up tendency. Seems to me that reverse should NOT be used on the centre engine until some time after touchdown, if at all. Just my 2 cents worth.

[Lyman]

prof2MDA

I agree, the energy was enormous, but you misunderstand. This a/c DID survive the last flop on the deck. But the wings did not. The MLG survived, but the wings snapped.

In BA038, the 777 had a push through and bellied to a stop. If, at Narita, the gear had failed, the results may have been similar, and survivable. Machinbird, where do I advocate an AD on gear structure? The 777 RMLG folded back, unfortunately entering the cabin and maiming a passenger, but the wings stayed on, the tanks maintained integrity, and what fuel was left (little) did not ignite. Narita was a firestorm from the initial failure of the spar on.

You conclude the gear architecture was not similar in design. How's that? The DC-10 was built post Phantom also, by the same company that had concluded that hard mounting the struts to the spars was survivable. Clearly, in Narita, they were not. Even if the design was inked by different teams, the fact remains, the Gear did not fail, and I conclude that if it had, the crash was survivable.

[Huck]

Reverse in the #2 engine on the MD11 is electronically limited to idle until the nosewheel is down.

[Prof2MDA]

PJ2 - the work was done by all the groups involved in the various investigations, which included very high time MD-11 pilots as well as engineers from a variety of entities serving as "watch-dogs", if you will. While it is true that many pilots believe certain things, that does not make them true. Many pilots also believe provably false "theories" of lift.

The issues that have been raised are not new, and have been raised and investigated many times now. If they were true they would have been part of one of the accident reports. I raised the "fear" aspect because ANY airplane will behave differently if the pilots are even slightly nervous flying it and it would be enough to explain the accident rate, particularly as the rate is still low enough to be within statistical random distribution.

Lyman - while it is true that the 777 gear folds first, it is also true that 777 gear will collapse at a lot lower amount of force than it takes to break an MD-11 wing (roughly double), so, while you can get to a catastrophic accident in the extreme case, how many times are you averting a lesser (and possibly fatal) accident in the meantime? It is not such a simple thing.

[Lyman]

pof2MDA

You are so right. I mean only to discuss, not pass judgment. Narita video is haunting enough without adding any blame to the airframe.

After the fire, I became transfixed by the Nose Gear strut protruding into the sky from an inverted and burnt out a/c. It occurred to me that the strut was responsible for the instant Pitch up of 30 degrees, and the roll left which caused the inversion. Had the strut collapsed, the Nose would have remained on the ground, and the a/c would have slid to a stop, perhaps. The wings I believe were already broken, from the hard contact; they broke downward, their weak spot.

When the wings were reloaded due the last Pitch Up, they snapped, and the right wing presented gobs more lifting surface to the airmass, hence the rollover.

If you review the video, you might be amazed at the strength of the NoseGear. That it survived is astonishing, at least to me.

[fdr]

the wings snapped off

No, it didn't.

refer the
report pg5,
figure 12 on pg21,
figure 15 pg 23
figure 16 pg 24

1.12.2.2 Main landing gear
The left main landing gear remained intact (Figure 16). The wing rear spar,
upper fixed brace, upper side brace, lower side brace, lock links, strut (PN
NRG6719-501, S/N BFGS 01027) and truck had no visible damage that would
suggest gear failure or strut over-compression. The chrome extension on the
strut measured 4.75 inches (in.) and the paint below the chrome did not
demonstrate signatures of strut over-travel. All four (4) tires were inflated.
The center main landing gear remained relatively intact; however, the aircraft
structure surrounding the gear attach points was largely consumed by fire. The
gear sat slightly forward and to the right of the normal down and locked
position. The strut ( no visible data plate), gear braces and truck had no visible
damage that would suggest gear failure or strut over-compression. The chrome
extension on the strut measured 9.5 in. and the paint below the chrome did not
demonstrate signatures of strut over-travel. The two (2) tires were inflated.


The right main landing gear remained intact. The wing rear spar, upper fixed
brace, upper side brace, lower side brace, lock links, strut (PN NRG6719-501,
S/N BFGS 01028) and truck had no visible damage that would suggest gear
failure or strut over-compression. A piece of speed tape type material was
located just above the junction of the upper side brace and upper fixed brace.
This speed tape was partially peeled back. There was also evidence of an
imprint on the bottom side of a wheel well upper panel that appeared to have
been made by a hinge located on the upper fixed brace. The chrome extension
on the strut measured 4.13 in. and the paint below the chrome did not
demonstrate signatures of strut over-travel. All four (4) tires were inflated

This MD11 wing and wing gear remained intact. Appendix B provides a table of hard landing incidents/accidents where in a number of cases the wing gear/aft spar has failed and results in a rollover, as in Kentucky, Hong kong or Narita.

[Lyman]

Sorry, fdr.

My reference was to Narita, not this flight, my bad.

[Prof2MDA]

Lyman

To which video of NRT do you refer? I can assure you that there are no publically available video clips that would enable any sort of analysis of failure paths.

[Lyman]

No analysis of failure paths? None? I'll have to stop observing the airport vid.

You disagree the Nose Pitched up due the remarkable tenacity of the Nose Gear?

You think it was elevator?

[Prof2MDA]

I think you are reading too much into my post. That said, failure paths require a lot more detail than you can get out of a grainy video.

[Lyman]

prof2MDA

What I read was a post that seemed to downplay the discussion. How many times in the past have there been no audio/visual records from the observer's pov? It is an asset, not a resource to downplay.

The chain (visual) is explicit, the forensics unknown at the time. Do we ignore the painful evidence?

There is a reason these cameras exist, and their use is important, albeit open to interpretation, and casual misuse. All records of revenue flight are important, and make progress possible, No?

cheers

[fdr]

Nose Pitched up due the remarkable tenacity of the Nose Gear?

You think it was elevator?

The data from the report is sufficient to put a few items to bed. The pitch down at touchdown was the result of the inertial moment of the aircraft following impact of the main gear, pilot unloading of the elevator at that point exacerbated the pitch down. The spoiler rise has acted against the pitch down input by the crew initially, and then the crew has applied a large pitch up input that has lagged the spoiler pitch up effect, and exacerbated that. The pitch up at the point of the 2nd impact is mainly the result of the spoilers and the elevator input by the crew, the NLG rebound does not need to add anything much to the rates to get the outcome.

would think that the take away is to avoid large stab inputs at the touchdown point, as we as humans tend to lag the dynamics by enough to get out of sorts. It does appear that had the elevator been held in the flare position for a couple of seconds, and then just washed out towards a neutral flare, that it just would have been a write up and debriefing event.

The simulators we use in general are pretty good, but they are not always representative of the real world in all aspects, even within the normal envelope. The QTG criteria permit a substantial variance from manufacturer dynamics vs the simulators performance. The particular MD11 sim when I evaluated it a long time back was problematic in many respects, particularly given the "advanced" training that was being conducted in it. LH appears to properly acknowledge the fit for purpose issue of the MD11 sim for landing training, and that probably is justified, but has high cost and increased risk.

If you feel like putting in full forward elevator in a flare/landing, I hope it is in the latter part of a J3 rollout, and not in any large conventional gear aircraft. It would be a warning to the system that the technique being employed has associated risks.

The LH aircraft held up rather well, and the crew are indeed fortunate that the MLG/aft spar didn't fail, that would have increased the risk to life considerably. The VS of the HKG MD11 was 1650FPM (IIFC) which is not far out from the third touchdown of this event...

[awblain]

Prof2MDA,

I took the still photos that showed the smoldering wreckage at rest upside down in Narita as a rather strong hint of a failed and folded wing, which was very consistent with what was seen on the grainy security video, and at previous MD11 crashes. The final investigation report seemed to confirm that.

[Machinbird]

The VS of the HKG MD11 was 1650FPM (IIFC) which is not far out from the third touchdown of this event...
Just for comparison, 1650 F/min = 27.5 F/sec which is higher than the advertised breaking sink rate for aircraft like the Navy F-4 which was around 24 F/sec.

The problem does not seem to be the landing gear strength, but the fact that the MD-11 can have an out of control arrival. This whole bit about having to come in with strong nose down inputs in some landing situations is the core problem. Get your timing off and you can be in a world of hurt.

Having the spoilers pitch your nose up when you should be de-rotating has to be a big part of the handling problem, which was the reason I mentioned the B748 problem and solution earlier. I'm surprised the FAA certified it like that. The aircraft should de-rotate in a more normal fashion.

[Lyman]

I think what I'm getting at, and could have started by saying it is that this aircraft may not be a solid candidate for its mission. There appear to be some razor thin certification numbers, pilots are cautioned to be with their A game on approach, etc. She is phenomenally short coupled, which may address why Machinbird has pointed out its reluctance to de-rotate. Aircraft with a centerline Bogie wear a familiar telltale of "Heavy Landing Prep", though that is not a disqualifier. Are the crew getting "behind" on approach, or is she sluggish in PITCH due the long forward moment, and the short swing of the tail feathers?

I saw one FEDEX downwind for SFO from my perch here in the marina. What an absolutely beautiful a/c. She does, however, have issues.

On short final, working the elevators is not good. Instead of PITCH control, the a/c experiences rapid migration of Center of LIFT, followed by a command to de rotate, which merely increases sink?

I wasn't intending to impugn the Landing Gear, Machinbird, strong is good. Just don't expect them to give it up when you bounce, better yet, don't bounce.

[Prof2MDA]

Lyman

1. It takes a lot more than a video to determine the failure path. A video can provide a data point, and that is all;

2. All long aircraft are subject to tail strike;

3. The control manipulations and wind conditions that have led to the accidents in RIH, EWR and HKG would have led to the same in the other types of aircraft as well.

[Lyman]

Short coupling attenuates the risk of tail strike. I am not trying to establish a failure path. She does NOT fly "like all other a/c."

Positioning the landing gear has more to do with a very high nose, which is not comfortable in the Flare. Long a/c get long GEAR. The design limits of an a/c are remarkably immune to scale.

I seem to appear as overly critical perhaps. No axe.

[goldfish85]

Cyranno,

I agree. It makes no sense to redact the registration, operator, and crew names. Particularly when they listed the serial number of the aircraft and the certificate numbers of the crew. Let's see .... how many German registered MD-11's crashed at Ryadh that day?

Apparently it was requested by the German accident investigation board, who have a history of hiding registration identification. This is happening in the US as well.

[Prof2MDA]

Lyman

How much MD-11 time do you have? What other types have you flown?

[Lyman]

Sorry, N/A. Here's why: No credentials I have will suffice once this question is demanded. You seek to distract from the discussion. If my questions spark interest, I hope it would be in the discussion, not my logbook.

[Cyrano]

Cyranno,

I agree. It makes no sense to redact the registration, operator, and crew names. Particularly when they listed the serial number of the aircraft and the certificate numbers of the crew. Let's see .... how many German registered MD-11's crashed at Ryadh that day?

Apparently it was requested by the German accident investigation board, who have a history of hiding registration identification. This is happening in the US as well.


Thanks for clarifying, Goldfish. I don't necessarily expect to see the crew names, but the registration and operator would be fairly obvious after a few seconds of Google search, so I am really not sure what the motivation for this apparent BFU policy is.

[Machinbird]

Sorry, N/A.
Just for curiosity sake Lyman, was that as in "Not Available" or "Not Applicable"?
I believe I saw a post where an alter ego of yours mentioned light twin time??

[Prof2MDA]

Lyman

MD-11 flying experience would, perhaps, not be an issue, however, when you wrote "She does NOT fly "like all other a/c." that begs the question as to what reference you have for that? It is a fair question based on your post.

[69flight]

Everyone is entitled to have his/her opinion about the MD11 and its good and bad sides. But for those who haven´t flown on the type, how can you compare its handling and characteristics with other aircrafts?
I´ve done a couple of thousand hours on it and I really loved flying this machine. We used to call "her" a "Diva". Why? Very simple. Treat her right and you´ll get the reward in form of a stable approach followed by a nice landing. But if, on short final, you let her go below approach speed or have a speed vector pointing way down when the auto throttle pulls the thrust back for the flare (of course you can override the retard) you might be running out of elevator force during the flare resulting most likely in a hard touch down.
But as long as you´re aware of this and remember basic flying it is not a difficult aircraft to fly.

Just my personal ´opinion´.:)

[stilton]

''Aircraft with a centerline Bogie wear a familiar telltale of "Heavy Landing Prep"



Er, what ??



Lyman, you don't appear to make any sense :confused:

[Gretchenfrage]

But as long as you´re aware of this and remember basic flying it is not a difficult aircraft to fly.

Nicely put and so true. It points at the originating problem: Basic flying skills.

Y'alls continue diverting discussions about video analysis, short coupling, landing gear design and other of your non flying hobbies ......... and you just keep on proving our point.

[ironbutt57]

A hard landing happens in lots of different types of aircraft, it's just the wing root failure/rollover that seems to be unique on the MD, 4 instances that I'm aware of....

[Burger Thing]

Loved flying the MD-11. I always found that with its LSAS, small, gentle inputs worked best on a approach. Similar to a FBW aircraft. It is airplane with a relatively high VREF and therefor initiating the flare at the correct height is vital, but I honestly don't think it has bad handling habits. Heck, I preferred the MD-11 in a crosswind compared to the Airbus I am flying now.

Automation and Flight Guidance was better in the MD-11, too, but that is another story.

[WASPERNATOR]

Hard landing! Again.. crew did the wrong thing. The MD11 does sound a little tricky to land safely?

[DOVES]

Excellent WASPERNATOR
Excuse me but I don’t understand precisely what You’re saying.
Do you mean that there has been another MD11 hard landing in the recent days?
If yes, can you please let us know where, how, when, why and under what circumstances it happened?

[ironbutt57]

Well, it didnt result in an accident, but I did observe a rather "firm" one recently in Dubai, followed by a cocked nosewheel on de-rotation which resulted in a large amount of smoke, and a tense moment or two for me, as I was approaching M13A and the nosewheel was pointing at me as it travelled past at a good clip:eek:, fortunately the aircraft didnt follow....

[Flightmech]

Don't mean to be rude but don't other types have "firm ones" now and again?? Normally as a result of seat-to-airplane interface?

[ironbutt57]

As I've mentioned previously yes,(might have even committed one me-self) just not every day you see the "nosewheel dance", and most certainly not the wing failing, fortunately this time is wasnt that "firm"....the airplane appears to be a bit "unconventional" in its handling characteristics...as passed on to me by several former colleagues who fly it...

[DBate]

Well, it didnt result in an accident, but I did observe a rather "firm" one recently in Dubai, followed by a cocked nosewheel on de-rotation which resulted in a large amount of smoke...

Be careful to judge a landing on the MD11 just by the amount of smoke you see generated on wheel spinup:

Several times I heard comments from other aircraft about our landings because of the amount of smoke, while the landing was absolutely normal and not firm whilst sitting at the controls on the flightdeck.

As for the nosewheel... hard to tell what happened there.

Cheers,
DBate

[ironbutt57]

No need to judge by the smoke, seen plenty of MD landings, and other types as well:ok:

[Weapons_Hot]

Couldn't agree with you more for those who have commented on basic flying skills required to land the MD.

For those who haven't flown it, well, there are those who have, and there are those who have yet to.

Further, Burger Things comments are very apt - in a savage Xwind, I prefer the MD to le Bus. Same goes for its FMS.

Keep the blue side up.