philipat;
Just to be certain, my comment regarding a configuration error as statistically "not significant" - it is indeed a serious, though highly infrequent operational issue.

In our flight data analysis program, we examine about 60,000+ departures per year of one fleet type. While we see other events of significance, we do not see takeoff configuration events. I further submit, again, without diminishing the seriousness of even one such departure!, that six accidents in 30 years (and many millions of departures) attributed to configuration error is not as statistically significant as, say, CFIT or mid-air/ground collision accidents, from which the industry has learned a great deal and dealt with in terms of technical and procedural response.
Well, everything and nothing. Human error is inevitable. What is not inevitable is individual response to error. Error can be engineered out of complex systems to a certain extent but no engineer and no one pilot can suggest ways which might eliminate all potential for error in all cases. Many times a beautifully-designed and even elegant system, like software itself, can perform for years and decades, only to be placed in singularly unique circumstances which, unforseen by all, defeats all efforts at prevention. Sometimes "who woulda thought that..." is the only response. Sometimes hindsight is genuinely chagrined and sometimes even learning takes place. Recall the many comments about money. In aviation, ever-moreso today, it is extremely difficult to get aviation managers and especially those who don't fly, to comprehend the risk that is so clearly perceived by some and never seen by others. Justifying expense, which in aviation is always very high, is tougher than ever. Sometimes it takes quite a lot of work and focus to ignore what is very plain to others in terms of risk but by and large the industry is very responsive to demonstrated risk.

As such, I personally would have nothing further to say with respect to "killer items" as this thread covers them sufficiently, for those with eyes, anyway. They're well known, well understood and from Hour One, are part of a pilot's toolkit for staying alive and keeping his/her passengers similarly alive. Certainly, nothing I say will add measurably to the helpful and professional dialogue that has already been extended on the subject.

For a very good read on these matters and human factors, I highly recommend that you read Sidney Dekker's, "Just Culture: Balancing Safety and Accountability" or "The Field Guide to Understanding Human Error" both available through Amazon and elsewhere.

FA10:

see post #376 for heresay

Ed agreed, and your incident sounds nasty, good call by the way! I once had a variable guide vane failure too but different and a much more boring story.

While not wanting to get too far off topic, I fly an aircraft with different engines. If it has the CFM56 I fly to N1 readings with no EPR indication. When I fly the V2500 I use EPR. So certainly with the CFMs N1 is the primary indicator of achieving take-off thrust.

Best regards. Tom.

Question for MD8x pilots:

On the MD82, with ATS engaged and TOGA or FLEX selected, in the event of a reverser unlock during takeoff, is the thrust lever automatically retarded to idle by the reverser mechanical interlock system and the ATS disconnected? If such an event occurred after passing 80kt or during rotation would an alert be inhibited until an altitude of 1000ft?

Thanks,
Green-dot

14 survivors still remain in the hospital. Luckily, only 1 remains in very serious condition (she is not expected to necessarily be able to fully recover from the coma). The rest, evolve favourably.

Our condolences to those directly affected.

I just ended a fast reading of the NW255 report, and I have some conclusions.

They lifted off the aircraft because were taking off from a 8500´ runway, and there wasnt much distance remaining. They forced the pitch up to get airborne.

If there was not a light pole, probably they didnt crash, because the plane was gaining altitude and decreasing their AOA very slowly. The report states that they only needed 11 degress of pitch up to stop the stick shaker.

Lateral inestability also appeared, they needed to overcome a dificult roll and gain control, and almost they did it.

In Barajas, there was plenty of take off distance available. Also probably ground effect. If we are talking about a no Slat/Flaps scenario, the chances of a succesfull take off in this kind of runway with this weather are high. Only the crew could worsened their odds keeping a high pitch angle, while ignoring the loss of speed and the warnings.

The NTSB estimated that an MD82 with the NW255 weight needed 11300 feet from the brake release point to reach 41 feet. In the runway 36L of Barajas you have 14272´of distance available.

You also need to take the human factor in to account.

This crew already had an aborted takeoff due to tech problems.

Everything might have appeared normal until leaving ground-effect.
The DC9/MD80 can be a handful to handle getting on the slow side for the flap setting.

Makes me think that when the pilots did identify the problem (no flaps or slats) it was too late to do something about it and recover.

From what I have seen with numerous DC9 series takeoff stalls (many due to ice on no-slat aircraft) the biggest problem was the loss of lateral control and/or roll just out of ground effect. True the aircraft may climb but not all the wings wish to follow and once you catch a wing tip it's all over.

I seem to recall that some aircraft e.g. Delta B727 and LH B747 dragged their aft fueslage over rough ground and that ended the flight.

As per post 1188 and the appropriate schematics, one can only deploy reversers with weight on weels. After taxi out, a flight control check has to be made, this is usually accomplished with flaps in T/O configuration to check operation of not only primary flight controls but spoilers as well. Can any MD80 pilots confirm this. Was not only the flight control check ignored, but also the before take-off check list mishandled and the crew failed on 2 seperate conditions to ensure proper configuration before T/O.

regarding the detroit crash, please remember that detroit is lower than madrid in elevation

that the detroit crash happened at night...and it is harder to fly at night as it is a semi instrument condition.

detroit was also cooler at the time of the crash than madrid was.


AND FROM THIS CRASH (detroit) ON, we learned: firewall power, flaps 15 if you stalled after takeoff...but somewhere that seems to have been lost.

we also learned a trick called "muscle memory"...that we couldn't takeoff without wiggiling the flap handle and making sure it was set in the detent.


long ago I suggested to my airline that we set flaps prior to leaving the gate area and have a visual confirmation by the mechanic in charge of pushback.

that didn't make sense to the boss

ha!

AirDisaster.Com: Special Report: Delta Air Lines Flight 1141

Please check out this link as the only accident I can find close to this one, if indeed the reports are true.

"long ago I suggested to my airline that we set flaps prior to leaving the gate area and have a visual confirmation by the mechanic in charge of pushback.

that didn't make sense to the boss

ha!"

As a non-pilot can I please ask a question about this point? .....and I hope it's not a silly one. I seem to remember that the airlines (I regular fly with) used to retract the flaps to T/O configuration at the end of a flight. In other words in the B737 ( at the end of flight) when the a/c is leaving the runway the flaps are not retracted to zero but to 5 degrees. This practice seems to have stopped in recent times, and the flaps are retracted fully and redeployed to T/O configuration when taxiing to position for the next flight.........just my observation

So did our chief pilot (SAS)
The answer was No Way, as you might hit something on your way out to the active rwy.

This has been covered in a post, looong ago, but here's a recap

If the airplane is in ground mode, here are a few obvious hints the Mad Dog will throw at you. Given their obviousness it's quite an effective system still for it's enginuity in verbally telling a pilot why the plane is not set for takeoff as is the checklist designed to filter out the chance of the crew not knowing.

if the plane is airborne......

1. You will get RAT probe heating on the ground. this is confirmed in the before starting checks as you turn on the anti ice, and set the knob to RAT current to verify it is at 0.

2. When taxiing out and doing flight control checks the "SPOILER DEPLOYED" caution does not illumintate as it should. This should raise a flag immediately, as the flight control check is vital to any crew.

3. The flight mode annunciators would read GO RND instead of TAK OFF when the TOGA buttons are pressed. So if you have you AP / FD system setup correctly, TAK OFF will not appear in the FMA, but GO RND. A definite clue that the plane thinks it's in the air.

These are the obvious ones. Because iether they are part of a checklist that must be accomplished or because the evidence is in the form of green LED's staring you right in the face with wrong info. Info which you verify verbally before every takeoff.

Indeed, if the plane is in airborne mode, the TO warning system is deactivated. This requires no explanation me thinks.

Xander

AOB9;
My (former) airline (I'm now retired), extends flaps to the takeoff position, (as planned and calculated during the cockpit check), after engine start and before taxi as part of the After Start Check.

The only time that procedure might not followed is in winter where the aircraft is to be de-iced first because it is snowing sufficiently so as to contaminate the inner leading edge surfaces (behind the slats) as well as the surfaces of the slotted flaps. The "After Start" check is then completed. The slats/flaps selection is left to just prior to takeoff if there is either freezing precip or wet snow falling - same reasons.

In the light of some comments on the thread, some may wonder about this procedure but in such weather, one is caught either way by risks which must be managed: - contaminated surfaces and/or a checklist item, either of which, if not respected, can produce the same outcome... The SOP is to extend slats/flaps just prior to takeoff in the above conditions, (which of course present their own separate risks and requirements).

However, the Airbus has a robust TOCW system which is tested as part of the Before Takeoff checklist and which will sound an aural warning plus light the Master Warning (red, for non-pilots) in front of both crew members when the thrust levers are placed in the FLEX/MCT or TOGA position. The TOCW is cannot be disabled by pulling circuit breakers.

I have done a max-pitch takeoff in the sim, (sidestick full back to the stop) where the alpha-prot mode maintains a "suitable" AOA (pitch around 25deg) while enabling 20deg-bank turns...once again, with slats/flaps in the takeoff position, (1+f). To be clear, I am unsure how this aircraft would perform in any slats-up/flaps-up takeoff but I'll bet some are trying it out in the sim as we write.

I think all planes will have the same happen to their TOCW system if the plane thinks it is airborne. The TOCW system will cease to work. Dirrefent aircraft will have different ways of telling you directly or indirectly if it is.
On the MD80 it will be the ones mentioned in my previous post. On the A320 it may be that you get presented wtih the landing config list instead of the TO config, maybe accompanied be something more directly.
In short, thinking it is in airborne mode disables all planes' TO warning system. That's more than logical I think.

Xander

We also changed our procedures to call for flaps after the before taxi check, but prior to calling for taxi. Our procedure was changed after it was discovered by FOQA that the flaps were not being set early enough in the process.

TOCW locked out in flight mode in not really the problem, it's the ability to be in flight mode while on the ground. How does this situation come to be (how does flight mode while grounded begin), and why hasn't this problem been addressed (assuming it's been known for ages)?

xander:
With respect, you simply can't make such a generalization. Not, at least, unless you've got Airbus 320/330 time and even then the statement is almost certainly incorrect. Christine works in mysterious ways our wonder to behold...

TOCW in flight is a huge problem, usually as the result of faulty prox sensors. Aircraft believes it is on the ground in flight. T/O configuration horn sounds, believing flaps and slats / leading edge devices are not configured for T/O. Outflow valves open and pressurization is rapidly lost. Mode S lost due to aircraft believing it is on gdn. The list goes on.