747 Splits in Two on T/O

[avbug]

No TR....we all make mistakes...hope this isn't true....

Again with the assumption.

What information do you have that indicates this was, or was not a mistake...or where has that been suggested?

The latest report suggests that the reversers were not deployed. The reason has not been shared presently, and accordingly any effort to suggest this is a mistake (were they unable, or did they have a valid reason not to deploy reversers?) is a wild assumption.

Wait for the facts.

 

[dutch747]

Again with the assumption.

What information do you have that indicates this was, or was not a mistake...or where has that been suggested?

The latest report suggests that the reversers were not deployed. The reason has not been shared presently, and accordingly any effort to suggest this is a mistake (were they unable, or did they have a valid reason not to deploy reversers?) is a wild assumption.

Wait for the facts.

I thought the preliminary was fact. I guess you have "speculated" that this is not fact? The report does not "suggest" that the TR's were not deployed either. Not that the TR's are going to make a rats arse difference in the stopping though. I'm sure Kallitta does not factor in TR's into their runway analysis anyway.

It's sound as though the abort was initiated after V1. I hope for my Kalitta brothers this is not true. I'll wait and see what the final report says. But still this is a FORUM Avbug. So anyone can say whatever they think happened. And then I expect you will rebut whatever is said.

 

[avbug]

I thought the preliminary was fact.

Well then; you thought wrong, didn't you?

The NTSB preliminary statement listed the wrong runway. The FAA's initial statement listed the wrong airport and wrong city. Go figure. While neither is handling the investigation, each is involved. Any preliminary report should be taken as a grain of salt. That's why it's a preliminary report. Even the NTSB, which is among the foremost authorities in mishap investigation, provides the disclaimer that the information may be inaccurate or incomplete.

Perhaps you didn't think at all.

It's sound as though the abort was initiated after V1.

Sounds? Sounds suspiciously as though you may be hazarding a guess, there. You've drifted from what you thought were facts, to guessing.

I guess you have "speculated" that this is not fact?

Nope. The poster to which I responded suggested a failure on the part of the crew to deploy the thrust reversers. that the thrust reversers are not deployed is clearly evident. That the crew failed in some way to deploy them, however is not.

Did the reversers fail? Did something occur which prevented their deployment? Did a condition exist which dictated best judgement not deploy them? We don't know. I speculated on nothing. My point is consistant as always; don't speculate. You dont' know; don't start rumor. To suggest the crew failed to deploy the reversers is guesswork, with no factual evidence to back it up. Perhaps they elected not to, perhaps they were unable. Until the facts emerge, it is always best not to guess.

Not that the TR's are going to make a rats arse difference in the stopping though. I'm sure Kallitta does not factor in TR's into their runway analysis anyway.

This is a part 25 performance issue, and yes, the reversers make a difference. That is, of course, irrelevant to the outcome here, as the reversers weren't used. The rejected takeoff procedure for the airplane, and for the operator, includes idle thrust, maximum braking, ground spoilers deployed, and yes, maximum reverse.

So anyone can say whatever they think happened.

Yes, they certainly can, can't they? Even if it's guesswork, entirely unsubstantiated, lacking for fact, guesswork, or a work of their imagination. Even if it contributes nothing but rumor. Even if they're an idiot for doing so. You betcha.

The humorous irony, of course, is that you're most offended by sticking to the truth and the facts. You'd rather celebrate ignorance and rumor. That's your privilege, of course...however unprofessional and foolish it may be.

 

[dutch747]

Thanks for the rebuttal Avbug. I'm not going to argue with you about this. But I do believe that TR's are not used in runway analysis for computing Max takeoff gross weight for a particular runway, and then of course V1.

Can anyone from Kallitta verify that TR's are not used in computing your runway analysis?

I know at the two 74 outfits I worked at it was not.

 

[avbug]

But I do believe that TR's are not used in runway analysis for computing Max takeoff gross weight for a particular runway, and then of course V1.

That's correct. TR's are a bonus, and not accounted in the rejected takeoff performance...same reason that RTO demonstrations for certification are performed with brakes only. Additionally, with maximum braking, any TR benifit is additive to the total deceleration, as opposed to a normal landing where minimum or medium autobrake settings modulate and the deceleration isn't increased by reverse thrust.

 

[Flyer8]

Can't speak to the 747 Thrust reverser issue as I am not qualified on that airplane. However,I do know that thrust reversers are not factored in for a rejected take-off or used in computing landing distances on our ATI DC-8s (they do have a tremendous amount of stopping power on the 71,72 and 73 series ) I used to fly the C-130 and L-382 and they used 2 in reverse and 2 in ground idle for computations. My point being that unless you happen to be a qualified Kalitta 747 crewmember,any speculation as to how or why reversers were used or not used is just that..Speculation...

 

[dojetdriver]

Like the previous poster I can't speak for the 747. But I thought per CFR certification, reverse is not allowed to be factored in for landing/RTO data.

 

[fareview]

From Flight International magazine's web-site.

Overrun Kalitta 747 suffered power loss but no engine damage
By David Kaminski-Morrow


Investigators in Brussels have found no evidence of engine damage on the Kalitta Air Boeing 747-200 freighter destroyed in a take-off overrun on 25 May, but confirm that one engine suffered a loss of power at a critical speed threshold.
The Belgian inquiry has also determined that the correct aircraft parameters, runway selection and weather data were uploaded to the 747’s computer before departure, and that use of runway 20 would not have posed any problems.
Two pilots, two engineers and a passenger accompanying diplomatic cargo escaped after the jet broke into three sections during the overrun. There was no prior structural failure; the break-up was caused by impact forces as the jet went over a 4m (13ft) drop.
“At this stage there is no reason to make urgent recommendations,” says the Service Public Federal Mobilite et Transports, which is heading the probe.
Analysis of the flight recorders, it says, shows the initial part of the take-off roll was normal, with constant acceleration until one of the Pratt & Whitney JT9D engines suffered a “momentary” loss of power.
This power loss, which was accompanied by a “detonation”, occurred as the aircraft reached the V1 speed – the threshold beyond which a crew normally must commit to becoming airborne, because the aircraft cannot be stopped safely on the runway.
The crew heard the noise and air traffic controllers witnessed flames from the right side of the aircraft.
Two seconds later the engine thrust was reduced to idle and the aircraft decelerated, but failed to stop before the runway end. Thrust reversers were not deployed, although a rejected take-off calculation does not take reverser use into account.
All four engines were operating as the 747 overran and, upon inspection, showed no sign of catastrophic failure. The engine cowlings were not punctured.
Following the indications of a possible problem with one of the right-hand engines, these were subjected to an initial endoscopic inspection of the high-pressure turbine and compressor.
“This inspection, although incomplete, failed to reveal any internal damage,” say the investigators. The fan-blades and low-pressure turbine remained in place and were similarly undamaged.
Specialists are to carry out a more thorough teardown and examination of the engine components.
None of the cargo pallets had shifted significantly during the accident, but the investigators are to check the loading distribution as part of the inquiry. The jet had stopped over in Brussels as part of a service between New York JFK and Bahrain.

 

[Redmeat]

avbug, were you crew? You must have been the way you're arguing.

Only one thing should have stopped that AC from going airborne after V1, and that is multiple engine failure which is about as likely as getting struck by lightning.

No matter what, after V1 the ship goes into the air. Successfully aborts after V1 are rare and the crew is lucky that the fuel tanks were not compromised (thanks Boeing) or they would be TOAST.

 

[dutch747]

I know Avbug will have my a$$ for this, but it's sounds like a compressor stall. Those JT9D engines are well known for it.