Spanair accident at Madrid

[el #]

This very discussion about "time/distance to V1", and the obvious possibility that is automatically checked / flagged by a system, has been had recently on pprune, but I don't remember on which thread.

If I'm not wrong, the outcome was that even if at first it seems something easy and inexpensive to implement in the interest of safety, it can also be opposed for reasons that I don't remember now, but are quite convincing when you hear them.

I do remember however that certain pilots stated they made silent or briefed commitment to abort if they not had reached, say, one half of R/W at the 100 Knts call that some do.

One further demonstration of how difficult is to have changes in the aviation industry and how tortuous is the road to the Good.

[Rananim]

"The National Transportation Safety Board determines that the probable cause of the accident was the flightcrew's failure to use the taxi checklist to ensure the flaps and slats were extended for takeoff. Contributing to the accident was the absence of electrical power to the airplane takeoff warning system which thus did not warn the flightcrew that the airplane was not configured properly for takeoff. The reason for the absence of electrical power could not be determined."

After liftoff, the wings of the airplane rolled to the left and the right about 35” in each direction.

The flight characteristics used to determine the stall speed of the DC-9-80 series airplanes are, in part, “A roll that cannot be readily arrested.. ”

The CVR recording showed that the flightcrew neither called for nor accomplished the TAXI checklist. The first item on the TAXI checklist required both pilots, in response to the checklist’s challenge, to check and verify orally that the flaps and slats were positioned correctly. This item was
not performed, and the flightcrew did not discover that the airplane was configured improperly for takeoff. The omission of the TAXI checklist was further corroborated by the flightcrew’s inability to
engage the autothrottles at the start of the takeoff because they did not, as required by the TAXI checklist place the TCI in the “T.O.” mode. However, they were able to rectify this omission by the time the airplane accelerated to 100 KIAS. Once the takeoff began, however, there was little chance they would detect any of the visual cues--the flap indicators in the up position, the absence of the blue takeoff light on the slat indicator light panel, and the absence of the ART ready light--that
might have alerted them to the fact that the airplane was not configured properly. All of the visual cues relating to the flaps and slats were located outside, or on the perimeter of, those areas normally
monitored by the captain and the first officer during takeoff. The Safety Board concludes that the failure of the flightcrew to accomplish the TAXI checklist in accordance with required procedures
was the probable cause of this accident.

Quotes from the NTSB report on NWA 255,a DC-9 that crashed on takeoff August 1987 in Michigan,USA.

Evidence against engine failure at Madrid is growing so maybe the answer lies in the past with this DC-9 crash?Is there any connection between the MEL work carrried out and disabling of takeoff config warning system??
I know practically nothing about the MD but the report spoke of 2 automated stall protection systems for the DC9;autoslat and stick-pusher,but both are disabled with slats retracted.Stall recovery technique is to apply and call for MAX POWER,FLAPS 15,release back pressure and avoid secondary stall.

The report speaks of six lines of defence against such an omission(failure to perform a checklist) :

The first line of defense was human vigilance; the second, another crewmember detecting error; the third, secondary indications, such as cockpit displays and instrumentation; the fourth, warning and alerting devices;the fifth, persons other than crewmembers detecting the error, i.e., ATC personnel or ground personnel; and the sixth, machines that take action on their own to rectify the error, i.e., the DC-9-82’s autoslat and stick pusher systems.

If you apply it to the Madrid case you can see how each line of defense could easily have been breached:
-vigilance-the tech problem and return to gate may have distracted crew and lowered vigilance levels
-another crew member detects the problem-"Do you want the before takeoff checklist?" or even "Did we do the checklist?"-again the tech problem could have upset their natural rhythm
-cockpit displays-the blue slat light or ART ready light-TCI not in TO mode distracts them and they miss all the signs and theyd be looking outside mostly anyway.
-warning device-takeoff warning system may have been disabled without the crew realising-was it checked pre-flight?Who checks it?both pilots?Its a major item..in my book,the skipper must check it but many airlines now have the First Officer checking these vital systems pre-flight while the skipper enters the flightplan in the computer!wrong way round.
-ATC-wouldnt apply here
-automated systems-autoslat/stickpusher disabled because slats retracted.

If it wasnt a takeoff warning system fault,then the other possibilities might be:
-blown tire at high speed..improved climb takeoff at hot/high airport,tailwind,slope.. all present at Madrid..
-thrust reverser deployment..but then why the bank left and then right?
- overweight or improper loading...with 2 engines working and correct takeoff configuration,less likely unless the discrepancy was sizeable..combined with another problem,like an engine failure or tire blowout,would be deadly.

[sevenstrokeroll]

Pichu 17 is quite right

pichu 17 is quite right...a current indication would not be present on the ground for the RAT probe heater.

AS I said earlier, if the RAT probe was being heated on the ground the EPR information would be very wrong.

Therefore, I believe the plane "thought" it was in the air (when the RAT probe is heated)...being "in the air" the takeoff configuration warning wouldn't warn the pilot if the flaps/slats were not extended.

IF the mechanic just disabled the heater of the RAT probe and didn't understand the plane "thought" it was in the air, the stage was set for disaster.

Of course by "thought it was in the air" simply means the ground shift mechanism wasn't working properly in one way or another.

[BelArgUSA]

The 3 "killers"

Please research some discussions published in Pprune about the "3 killers"...
One or two years ago...
The 3 single reasons why an airplane will crash on takeoff...
TRIM, FLAPS, SPOILERS...
Check list completed or not - every time I line up for takeoff, I CHECK my 3 killers.
xxx:

Happy contrails... repeat after me... TRIMS-FLAPS-SPOILERS

[Dairyground]

Deviation to the left

VanHorck and PJ2 (posts #771 and 772)

The El Mundo graphic shows a deviation to the left before veering off to the right. First time i heard that one! Deviation to the left due to the left engine failing and over-correction to the right leading to touching the right wing briefly as often stated?

There is a claim by a distant observer, reported in post #202, that dust was being raised from the ground on the left of the runway before the first grounding of the right wing. Whether reflecting reality or otherwise, that report may underly graphics that show an initial deviation to the left.

[HarryMann]

The 3 single reasons why an airplane will crash on takeoff...
TRIM, FLAPS, SPOILERS...

Maybe add ICE to that... (a form of inadvertant configuration malaise)

[Rananim]

sevenstrokeroll,
Let me get this straight.You're saying failure of air/gnd system?Surely there would be more indications of such a failure than just this probe heater warning?Like antiskid/RTO disabled,cant set parking brake...

[dicksorchard]

thrust reversers ?

justme69 A photo of the wreckage seems to show one of the engine with the thrust reverser engaged and locked, indicating either an attempted abort during take-off (or forced landing, depending on how you look at it, as it seems to have happened seconds after airbone).

I am very curious about this statement my reasoning being that a very good friend
( ex monarch captain 17 years ) and i were having a discussion on the telephone about this accident yesterday .

I was talking about the fact that there was a lot of discussion on Pprune about the direction in which the aircraft veered off the runway versus the supposed engine failure and its position .

One of the first things he said was that it sounded more like an attempted abort & the thrust reverser had possibly been activated ? when i told him that the thrust reverser had been photographed and that it was engaged & locked he went very quiet .

I wanted to ask have there ever been any other accidents where a thrust reverser was engaged in error where an aircraft had crashed ? and have there ver been any incidence's where a thrust reverser engaged due to a mechanical fault of some kind ?

im not a journo just someone who is very interested in aviation & off corse my own personal safety . The more i learn the more informed i become .

thankyou

[sevenstrokeroll]

rananim:

I've been in the cockpit flying the mighty 9 (earlier version...dc9)...just sitting at the gate reviewing takeoff info.

Checking what we call the rat / epr gauge/display, the takeoff epr was very very low.

this can't be...something doesn't make sense.

so, we looked around...called mx, and a wise old mechanic came out...said:

the plane thinks its in the air and the RAT probe is being heated on the ground when it shouldn't be. so the rat probe thinks the temperature for takeoff is about 50 degrees C. (much warmer than the 20c actual).


he showed us a circuit breaker (can't remember where) that had popped, reset it and a few seconds later the RAT probe cooled down and showed a normal epr for takeoff.

the other things you mention may or may not be present...but at slow speeds, the anti skid doesn't matter on the douglas etc.

I think those in charge of the investigation must be considering this scenario...or something close to it.

[curi]

Some photos of the engines

[sevenstrokeroll]

did I see something about the flight data recorder not working right?

if so, I just checked my old DC9 manual ( I was on the 9-30, not the 80, but things should be simliar)

the flight data recorder would be affected by the ground shift mechanism.

also, the anti skid is not affected by ground shift according to my manual.

can someone confirm the FDR wasn't working right?

[philipat]

Engine Issues not conclusive on video?

It is a shame that full ground TO video WITH AUDIO is not available. Eye witnesses are notoriously unreliable but the reports of hearing a loud bang, also repeated by some of the survivors are intriguing. Also, the ground video, taken from Terminal 4, presumably only see the near/Port side of the aircarft on 36L, although this is not clear also. I am just wondering outloud if, after all the earlier speculation of possible failure of #1, that it might actually have been a problem with #2? Such failure, which may not necessarily have been accompanied by fire, but probably would have been accompanied by a loud bang, would have been out of the visual/audio capability of the video?

[Airbubba]

-warning device-takeoff warning system may have been disabled without the crew realising-

Or, even worse, in the NW255 crash, it is thought that the crew may have pulled the takeoff warning breaker to avoid the nuisance horn while revving an engine up during single engine taxi inbound to DTW. Pulling cb's was common practice a couple of decades ago from my observation. In one of Delta's DFW crashes the takeoff warning horn was found to be inop and the flaps were up although the checklist response for flaps fifteen was given.

Modern Boeings will not engage the autothrottles for takeoff with flaps up (so I'm told ), perhaps this came from the NW255 crash.

[justme69]

At least 4 different people, two pilots and two politicians that have seen the footage plus an additional politician that had the events of the tape explained to him first hand by another viewer of said tape, have all stated, quite cathegorically, that no fire, smoke or large faults can be VISUALLY OBSERVED from the tape and sort of implied that the visual was good and that the plane looked perfectly "normal" until it started "hitting" the ground. One politician even goes as far as suggesting that "nothing about the cause of the accident can be directly observed by watching the tape" (i.e. everything looked pretty much normal to those who've seen it, except for that "apparent" lack of "power" to accomplish take-off and the erratic behaviour once airbone).

The Flight Data Recorder has been reported as "damaged" (rather than non-operative, not-working or broken, but implying that unlike the voicer recorder, this one can not have the information recovered "as-is" and perhaps some information could be lost).

One of the major newspapers in Spain ran a new article concentrating on the possibility of one of the reversers being accidentaly deployed, but mentions that the airplane didn't show any signs of having trouble keeping a straight line while taxing or rolling.

Here are the highlights from that article:

-They estimate the landing strip at 4.440m and 60m across, with the airplane leaving the ground about an estimated 500m over the recommended or usual run for the flight.

-Video shows that the airplane starts to go "off-course" (deviated from a straight line) after elevation, not before. After reaching "almost the end of the runaway", it goes up a few meters, during 6 seconds, and then falls "escorado" (not sure the term here, would be with one wing lower than the other) to the right. The first thing to touch the ground is the wing. It bounces no less than 6 times on the runaway (pavement) and then "explodes". That's what the article says, but probably not exactly how it happened, but close enough.

-One of the engines was recovered properly reversed.

-Tail wind again reported as 9knots. Meteo measurement at 14:30, about 7 minutes after the crash, was 7knots from south.

-174 on board, they estimate 15 tons including luggage plus around another 15 tons of fuel. The same plane was sometimes used for Canary Islands-Denmark flights, where weight is usually even higher.

-They say Barajas Airport is 610m above sea level. They quote temperature as being 28º (I've read 29º and 30º on different places).

-There is no communications with ground control from the moment they receive (and ack) autorization for T/O.

-Speaking about the prior return-to-gate, they say: "The pilot decided to turn around and request service when he realized the outside air temperature probe measurements were too high. It was found to be because the anti-ice heater was on. The mechanic disabled the heater." (Finally, a likely scenario and would account for the earlier reports of the pilot speaking of "overheated sensor").

-Spanair has reviewed all past historic maintenance data for the airplane and it was all according to regulations, with no inspections finding unusual problems with engines in the past, etc.

[PJ2]

sevenstrokeroll;

the flight data recorder would be affected by the ground shift mechanism.

I think most DFDR's start with the anti-collision light being turned on and continue until it's shut off - I believe that's the way it worked with our '9's and '8's but that's going back about 30 - 35 years.

I think earlier in the thread it was mentioned that apparently there was some damage to the DFDR. - possibly heat damage.

[skyken]

I'm glad I retired after 40 years. You guys know way more than I'll ever know.

[xkoote]

The FDR would still be operative. Remember, the only thing happening is that the plane "thinks" it's airborne and thus the FDR normally works when airborne.
Indeed if the RAT probe is heated on the ground, it could give high readings to the DFGC. But remember it was disabled, so it should not have been a problem for the subsequent TO.

I strongly beleive that they tried an RTO becuase the landing gear failed to retract. The gear will not retract if the plane arrived in this condition!
If the plane indeed was in airborne mode, remember my words. This is an item in the MD-80's Emergency Abnormal Checklist.

Xander

[PJ2]

dicksorchard:

I wanted to ask have there ever been any other accidents where a thrust reverser was engaged in error where an aircraft had crashed ? and have there ver been any incidence's where a thrust reverser engaged due to a mechanical fault of some kind ?

Try Pacific Western Airlines B737, Cranbrook, 1978

[PJ2]

xander;

I strongly beleive that they tried an RTO becuase the landing gear failed to retract. The gear will not retract if the plane arrived in this condition!
If the plane indeed was in airborne mode, remember my words. This is an item in the MD-80's Emergency Abnormal Checklist.

Nonsense. There isn't an airline crew in existence which would attempt an RTO if "the gear failed to retract". I know of no such drill in my 35 years' experience which would be included in any Emergency Abnormal Checklist. Logic alone precludes such an outlandish suggestion.

[philipat]

Location of Engine

The earlier picture of an engine with TR engaged continues to confuse. The picture appears to show the engine at the END of a runway. I wonder if that was a genuine picture and, if so, how can that be?