BA 747 crew commended for escaping near-stall on take-off

[Lear70]

Not 100% sure but I believe on the 747-400 that if the auto throttles are engaged, any indication of thrust reverser unlock will auto-retard and idle the applicable throttle. In that scenario, you'd have 3 good engines producing power, 1 engine at idle in reverse. Pretty sure it will fly just fine like that, but again, I haven't flown the whale.

Now it depends what EICAS indicated whether I'd choose to try to abort a takeoff above 100 kts. My normal brief includes, "Abort for anything under 100 kts, above 100 kts we're only aborting for an engine failure, engine fire, loss of directional control, or inadvertent thrust reverser deployment". However, that's in a two-engine aircraft where a thrust reverser deployment is pretty nasty business above V1.

If it was just a momentary EICAS message that disappeared right after I looked at it with NO indication in the directional control of the airplane to accompany it? I might not reject the takeoff, either. Accompanied by directional control issue (confirmation of an actual T/R deployment), yeah, under V1, I'm rejecting, but that's me.

But I'm not Monday Morning Quarterbacking a successful outcome of the maneuver, that's for sure. They made it work, good for them.

 

[Beefy Botham]

That scenario does not occur on a B747-400.

 

[tailwindz]

I profusely apologise to the BA crew for not acknowledging your superior airman-ship and decision making in your Joberg departure on my first post. Well done. If I ever have the pleasure of meeting either of you around the world, the night is one me. An awesome display of airman ship.

Needles to say, I am impressed.

Mr Wu, If you had asked, rather than attacked a crew that actually accomplished an amazing feat, I would explain. Right now the level of contempt I have for you and the others on this board that have the ignorance to question such an event speaks volumes about you. Good luck in your career. My only fear is that I have to position on an aircraft that you are in a front window seat of.

 

[Mr Wu]

I profusely apologise to the BA crew for not acknowledging your superior airman-ship and decision making in your Joberg departure on my first post. Well done. If I ever have the pleasure of meeting either of you around the world, the night is one me. An awesome display of airman ship.

Needles to say, I am impressed.

Mr Wu, If you had asked, rather than attacked a crew that actually accomplished an amazing feat, I would explain. Right now the level of contempt I have for you and the others on this board that have the ignorance to question such an event speaks volumes about you. Good luck in your career. My only fear is that I have to position on an aircraft that you are in a front window seat of.

Save your whining for someone who cares. You answered my question - you don't know.

 

[avbug]

Sleeve somewhere between stowed and extended.

Negative.

Pretty sure it will fly just fine like that, but again, I haven't flown the whale.

Then what makes you "pretty sure?"

So educate me. How much runway does a "whale" near gross weight need to get from 125kts to 167kts on 3 engines and one in reverse at T/O power?

Not even the performance programs or charts will tell you this, as it's nonsensical. It's also irrelevant, as in the case in question, an engine was not in reverse at takeoff power.

The QRH procedure, which is not a memory item, for a reverser unlocked in the -400, is as follows:

Condition: REV annunciation displayed with reverse thrust not intentionally selected.

With no yaw, loss of airspeed, or buffet:
--Operate engine normally.

With yaw, loss of airspeed, or buffet:
--Fuel Control Switch, affected engine: CUTOFF
--Transponder Mode Selector: TA ONLY

Do not accomplish the following checklist:
--Engine Shutdown

Buffet may be reduced by decreasing airspeed.

Landing Preparation:
--Use Flaps 25 and Vref30 + 20 for landing.

Imagine that. Operate normally, with no yaw, loss of airspeed, or buffet. Do not shut down engine or follow engine shutdown checklist. Go figure.

Now, several here have lambasted the crew for not pitching to the stick shaker. The airplane was already there. Several have thrown in their "I woulda done this," or "I woulda done that" two cents worth, with obviously no Boeing experience, and certainly no 747 experience. The crew did what they could, given the circumstances. The crew did not have an engine in reverse, and didn't have an engine in reverse at full power. The sky is not falling, and the boogie man hasn't come out of the dark staircase just yet. The crew had a very unusual issue with which to deal, and they dealt with it well.

As for a rejected takeoff in the 747...http://2.bp.blogspot.com/_zjtdEB0M1...pUfk/s1600-h/KalittaN704CK-BRU080525-AAIU.jpg

A loaded takeoff the the 747 means you'll be seeing the red lights at the far end when you rotate, most places you go. There are very few indications that merit rejecting (not aborting) a takeoff. A reverser indication without yaw, loss of speed, or buffet isn't necessarily worth a high speed rejected takeoff.

Not 100% sure but I believe on the 747-400 that if the auto throttles are engaged, any indication of thrust reverser unlock will auto-retard and idle the applicable throttle.

Verbatim from AOM Volume II:

The thrust reversers are protected against deploying inadvertantly. If a reverser unlocks and deploys inadvertantly, the reverser system applies bleed air to stow and lock the reverser.

 

[Dan Roman]

Good post Avbug. The bottom line is, anytime you second guess someone you usually are at least half wrong. They and Sully/Skiles both did a great job, period.

 

[j41driver]

Geez, I thought this was a section for mature individuals.

Nope. This section is no different than the rest of FI.

 

[Lear70]

Then what makes you "pretty sure?"

Boeing Certification and several years of command on the 727.

Would imagine it would be difficult to obtain certification if the aircraft was NOT flyable with 3 good engines and one in reverse... but thanks for asking. :/

 

[Lear70]

1st warning.

Do NOT discuss East/West issues in anything but an East/West thread. Period.

The next infraction results in a suspension for 7 days.

/mod

 

[get2flyin]

1st warning.

Do NOT discuss East/West issues in anything but an East/West thread. Period.

The next infraction results in a suspension for 7 days.

/mod

But we're both so self absorbed...isn't EVERYTHING about us?