AF777 TOGA after thrust reverser deployment

[Eutychus]

[mods please move if this is in the wrong place]

A YouTube channel I follow has just reposted this video

this video

of an AF 777 landing at Mumbai, starting to deploy thrust reversers and then doing a go-around. That sounds like a risky call to this SLF*. Isn't one committed to landing after thrust reverser deployment?

*My main qualification here is having flown *out* of Mumbai once right at the back of an A340 with AF's now-defunct low-cost long-haul operation Joon...

[tdracer]

Originally Posted by Eutychus

[mods please move if this is in the wrong place]

A YouTube channel I follow has just reposted this video this video of an AF 777 landing at Mumbai, starting to deploy thrust reversers and then doing a go-around. That sounds like a risky call to this SLF*. Isn't one committed to landing after thrust reverser deployment?

*My main qualification here is having flown *out* of Mumbai once right at the back of an A340 with AF's now-defunct low-cost long-haul operation Joon...

As I recall, the AFM says something to the effect of 'Go-Around not recommended after thrust reverser deployment'.
That being said, it does happen, and all current Boeing products are designed to accommodate it (outgrowth of the 737-200 crash at Cranbrook - go-around after a snowplow appeared out of the snow after T/R deployment - one T/R didn't complete the stow cycle and lock prior to liftoff and aero forces caused it to deploy again.).

[Disso]

Very relevant Mentour Pilot episode covering this, ironically, just posted named "A FREAK Coincidence?! Tap Air Portugal flight 754". (I can't post links yet)

FWIW, he is extremely adamant throughout the video in concluding that once reversers are deployed, you are 1000% COMMITTED to completing the landing and NOT going around.

[Propellerhead]

Once reverse is selected a full stop landing must be made. As you allude to, the air Portugal close call is why, where one stayed in reverse.

[tdracer]

Originally Posted by Propellerhead

Once reverse is selected a full stop landing must be made. As you allude to, the air Portugal close call is why, where one stayed in reverse.

That's fine on paper, but what would you do if, seconds after you selected reverse, a vehicle or another aircraft appeared on the runway? Just go ahead and run into it?

[Dct_Mopas]

Originally Posted by tdracer

That's fine on paper, but what would you do if, seconds after you selected reverse, a vehicle or another aircraft appeared on the runway? Just go ahead and run into it?

….or try a go-around. Thrust reversers stow, then build up to TOGA thrust from idle once again, slowly get airborne and clip the obstacle at high speed.

If reverse has been selected you stay on the runway and stop. If the obstacle is so close that you can’t stop in time with maximum braking then you most certainly can’t miss it by trying to get airborne again.

[tdracer]

Originally Posted by Dct_Mopas

….or try a go-around. Thrust reversers stow, then build up to TOGA thrust from idle once again, slowly get airborne and clip the obstacle at high speed.

If reverse has been selected you stay on the runway and stop. If the obstacle is so close that you can’t stop in time with maximum braking then you most certainly can’t miss it by trying to get airborne again.

Cranbrook took off in time to miss the snow plow - had the reverser stayed stowed (which, as I noted earlier, has been corrected on Boeing aircraft), it would have been a non-event. If you're going well north of 100knots, it takes a long time to stop vs. taking off again.

Granted, not something that any sane person would plan, but with faced with a certain collision at speed, or getting airborne again, you need to make a rapid decision and then just pray it's the right one. The aircraft design shouldn't be the limiting factor.

[Capn Bloggs]

If reverse has been selected you stay on the runway and stop.

Or, take it on to the grass. Touchdown at 130ish, full braking, max reverse will take you quickly to towards 100, a runway excursion at 100, with all the gear down and full reverse won't seriously hurt anybody. You don't have to "just run into something", in a car or aeroplane.

Originally Posted by TDRacer

If you're going well north of 100knots, it takes a long time to stop vs. taking off again.

You'd be surprised. Reverser stowing, spooling up, then finally commencing acceleration back to ~140 will take you longer than a max effort stop from 100kt.

717 FCOM:

​​​​​​​

[rog747]

If I was sitting in that seat and saw that happen then my bottom hole would be tweaking ever so.....
I heard the note of the engines drop, and then there was seemingly a lag in spool up,
I wasn't too happy LOL.

Glad they flew out of it.

[Propellerhead]

Of course a Commander is authorised to deviate from rules and procedures in an emergency in order to ensure the safety of the aircraft. I don’t believe this was the case with the Air France. To deviate from a Boeing warning in bold type would have to be pretty extreme. Boeing have the risk assessment in the cold light of day.

[mnttech]

Originally Posted by Capn Bloggs

717 FCOM:

717 or 777? Just because it is in one airframe does not mean it is in another due to the design of the reversers. Some older aircraft used bleed air if I remember correct.
That said, the spool up time I would think would be one issue, let alone if one reverser had an issue.
Are 777 reversers hydraulic on all engine variants ?

[Capn Bloggs]

That is indeed the 717. I don't have a current FCOM for the 777, but an early version I have says essentially the same thing, but not in a Warning box.

[Beakor]

B787 Flight Crew Training Manual 6.21:

“WARNING: After reverse thrust is initiated, a full stop landing must be made. If an engine stays in reverse, safe flight is not possible.”

[tdracer]

Originally Posted by mnttech

Are 777 reversers hydraulic on all engine variants ?

Yes. Not true on many other models though (CF6-80C2 on the 767 and 747-400 are pneumatic for example. while the PW4000 is hydraulic).

[ploughman67]

Originally Posted by Beakor

B787 Flight Crew Training Manual 6.21:

“WARNING: After reverse thrust is initiated, a full stop landing must be made. If an engine stays in reverse, safe flight is not possible.”

Identical wording in the B777 FCTM

[Disso]

Not surprising that such poor airmanship directly against the FCTM is being committed by AF pilots smfh.

[Check Airman]

Has there been any attempt to determine WHY this was done, or are we sending them to prison without a trial?

I’m sure everyone’s CAA has a paragraph similar to this:

§121.557 Emergencies: Domestic and flag operations.

(a) In an emergency situation that requires immediate decision and action the pilot in command may take any action that he considers necessary under the circumstances. In such a case he may deviate from prescribed operations procedures and methods, weather minimums, and this chapter, to the extent required in the interests of safety.

[tdracer]

Originally Posted by Beakor

If an engine stays in reverse, safe flight is not possible.”

I think that part is the key of the statement - "If an engine stays in reverse".
As I noted previously, Boeing reverser design has been changed so that - baring a failure - the reversers won't stay in reverse even after liftoff, they will continue the stow cycle until they are stowed and locked.
That wasn't the case with Cranbrook - where as soon as air/ground went 'air', all power was removed from the reverser and it was unable to complete the stow cycle.

[Eutychus]

Originally Posted by Check Airman

Has there been any attempt to determine WHY this was done, or are we sending them to prison without a trial?

I guess part of my question in starting this thread is whether an event like this does or should trigger any debrief, incident reporting procedure, crew debrief, etc. Either before and after video of the incident goes on YouTube.

(One comment on the video asks whether the captain might not have taken back control from the FO, belatedly, to initiate the go-around).

[FullWings]

It would be interesting to know what the reason was, as it would have to be a seriously good one to reject the landing after reverser deployment. As AF is an EASA operation, they should have done a IFLD assessment, which would have given a stopping margin and gates for a safe touchdown and rollout. Thinking about the sequence of events: flare and thrust to idle, touchdown, reverser deployment, reverser stowing, thrust to GA, accelerate to Vref then rotate, the amount of runway used between touchdown and the wheels leaving the runway again would be substantially more than a normal rejected landing, due to the reversers going in and out, presumably while braking was ongoing.

I’m fairly certain that FOQA would trigger an investigation for this incident, but it would likely be an internal one, unless it was deemed serious enough to pass to the regulator, and even then it may never make it into the public domain.