PPRuNe Forums - BA 321 tail strike?

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TOGA 10 was used, but should not be used on an A321 as the tailstrike limit is 9.5 degrees. Therefore it now says to adjust attitude, which may mean to derotate or holding the attitude until the aircraft has safely transitioned into an initial climb, at which point the normal go around procedure will be initiated. Since the flare law (below 50ft RA) allows a pitch power coupling, setting TOGA thrust will most likely increase the pitch, so no further pitch input is needed initially, quite the opposite in fact.

As an administrative question: Why the heck was this thread moved to the "Non Airline" section of PPRUNE? This was very much an airline incident.

Quote:

Originally Posted by RexBanner (Post 11178367)

What’s most amazing about this video is that there was actually footage of a (mini) Airbus landing. Surely there must have been an A350 or 787 moving somewhere on the apron at that moment, that’s what he normally prioritises? :rolleyes:

On ‘Big’ Jet TV. I wonder why…:O

Quote:

Originally Posted by Twiglet1 (Post 11178586)

Dave the guy was doing a live transmission so he was stating what he thought at the time.

I wasn't referring to the histrionic live commentary, but to this, still visible nearly 24 hours later:

https://cimg5.ibsrv.net/gimg/pprune....23912b4d5c.jpg

Note the "empennage shaking as it drags" ...

So I stand by my comment.

Quote:

Originally Posted by andrasz (Post 11178120)

I would assume TOGA was already pressed moments before the second touchdown.

Press TOGA? But this is an Airbus.

Quote:

Originally Posted by Denti (Post 11178621)

https://cimg9.ibsrv.net/gimg/pprune....5accdf505.jpeg

This late in the landing phase your aircraft is trimmed nose down. TOGA will increase the pitch, but not enough. Simply holding the attitude will probably initially require a nose-up input.
By the way, „TOGA-10“ („TOGA-7.5“ for A321) is still used in my company for manual go-arounds below 50 feet.

Toga 10 is a good figure to have in mind for the A320, I suppose toga 7.5 will work well for a 321. There is little guidance for it, but have seen it taught in the sim for a rejected landing.

I'd hazard a guess that the thrust levers weren't brought to idle by touchdown for whatever reason, that would explain why the spoilers didn't extend during the first touchdown and the prolonged float afterwards.

I'd also expect that startle played a part in this incident.

Quote:

Originally Posted by tubby linton (Post 11178531)

a 31/01/2022 12:20->metar cor egll 311220z auto 34011g22kt 290v020 9999 ncd 08/m04 q1025 nosig=
sa 31/01/2022 11:50->metar cor egll 311150z auto 32017g27kt 300v020 9999 ncd 08/m03 q1025 nosig= sa 31/01/2022
11:20->metar cor egll 311120z auto 32014g24kt 9999 ncd 08/m02 q1024 nosig=

So wind was hardly an issue…

It will be nice to learn eventually which moment was TOGA selected (=commanded) and see it on the tape.

Despite the gruesome comment style of BigJetTV (fully with Dave on this one), incidentally, this really should be used for training in a broader sense. Everyday line pilots even on short-haul only go around less than once a year. Understanding if this crew slipped and why, or what happened externally to deviate from the typical profile will be helpful to anyone who gets the chance.

It's nothing but a personal guess, the 2x 33k TOGA thrust on a lightweight 321 will have significant pitch-up with stick released (same as Denti suggested). I assume nobody really knows what happens to the frozen THS and the flare nose-down command after getting airborne from a bounce. But there was a NEO (?) bulletin about aft CG where the FBW could not provide the normally expected stable pitch.

The first usual suspect is the actual pitch at 50' which is memorized as a reference zero for the flare mode. Getting that wrong (markedly lower than normal) can bite seriously below 20'.

Quote:

Toga 10 is a good figure to have in mind for the A320, I suppose toga 7.5 will work well for a 321. There is little guidance for it, but have seen it taught in the sim for a rejected landing.

”TOGA 10” was actively de-trained in BA some years ago. Partly because it’s not an Airbus recommended technique and partly because it’s too prescriptive.

Again with the generalisations. When I was doing the day job I certainly went around more than once per year. Actually in orange world twice in one day. Maybe it’s just me. I’m also not sure how this is of any benefit to a training department except how not to do it. In fairness, it could be line training and / or low currency. I have actually been in this situation line training a cadet (stand by for incoming) and late intervention combined with startle resulted in a similar situation (737). What actually happened in this incident was a high early flare, a couple of bounces, a wind induced wing drop and an over enthusiastic rotation almost but not quite tailstrike. In fairness to the crew if they read this, we’ve all been there, review what happened, learn and move on.

Quote:

Originally Posted by NineEighteen (Post 11178629)

On ‘Big’ Jet TV. I wonder why…:O

define big… ;)

(I don’t recall the control tower lift being a heavy jet either but attempting to film that was prioritised over documenting a landing on one occasion that I can recall)

Quote:

Originally Posted by EmDeer (Post 11178665)

Just a correction here. On the A321 NEO, the flare mode is quite unique; It is not the same as other A321CEO, A320 CEO and A320 NEO. There is no nose down trimmed at 30 feet and the THS is frozen at 100ft RA ISO 50ft RA.
From FCOM:

Quote:

When passing 100 ft RA, the THS is frozen and the normal flight mode changes to flare mode as
the aircraft descends to land. 'The flare mode is a direct stick-to-elevator law without auto trim,
with some damping provided by load factor and pitch rate feedback. The flare law provides full
elevator authority. The flare law does not compensate the ground or thrust effect.

And from FCTM:

Quote:

AIRCRAFT SYSTEM FOR TAIL STRIKE PREVENTION
The following aircraft systems help to prevent tail strike occurrence:
A "PITCH-PITCH" synthetic voice sounds when the pitch attitude becomes excessive,
A tail strike pitch limit indicator appears on the PFD to indicate the maximum pitch attitude
to avoid a tail strike.
The "PITCH-PITCH" synthetic voice sound takes into account the actual pitch value and the pitch
trend. This can lead to "PITCH-PITCH" synthetic voice sound to be triggered before any PM callou
or before the pitch reaches a high attitude on the PF:
This design is installed as an option on A320 and A321.
BOUNCING AT TOUCH DOWN
In case of light bounce, maintain the pitch attitude and complete the landing, while keeping the
thrust at idle. Do not allow the pitch attitude to increase, particularly following a firm touch dowr
with a high pitch rate.
In case of high bounce, maintain the pitch attitude and initiate a go-around. Do not try to avoid
second touch down during the go-around. Should it happen, it would be soft enough to prevent
damage to the aircraft, if pitch attitude is maintained.
Only when safely established in the go-around, retract flaps one step and the landing gear. A
landing should not be attempted immediately after high bounce, as thrust may be required to
soften the second touch down and the remaining runway length may be insufficient to stop the
aircraft.

My guess for the non spoiler deployment during touch down was that the PF did not set both thrust levers fully at idle. It’s mandatory for both levers to be on idle for spoilers deployment. Or they forgot to arm it on final. But unlikely as easily spotted on the landing memo.

From FR24, the aircraft in question - G-NEOP - did a return flight to GVA afterwards on 31/01 but has not flown since. Looks like it may be back in service on 03/02 with a trip to DME.

Perhaps they took the aircraft out of service for an inspection having seen the video? Or maybe just routine spannering?

Quote:

Originally Posted by Suzeman (Post 11178852)

I wouldn't attach too much importance to its inactivity - most of BA's 321neos have had extended stretches of downtime lasting several days in recent weeks.

Eagle and 4468

Quote:

This quotation is incorrect as it only applies to the rollout in crosswind conditions (once the nose-wheel
is down)

The quote is correct and directly from the FCOM and exactly to which I refer. To clarify I am not talking about the approach and flare but post touchdown. The aircraft actually transitions from Normal to Flare to Direct law so if crabbing and using rudder to align the nose you will get the secondary effect of roll depending when you do it. But once down in strong crosswinds it was always then advisable to keep a little into into wind aileron during the initial rollout to avoid any subsequent wing lift as seems to have been a factor here.

Absolutely no interest in assigning blame or judgement on the crew. I am however genuinely surprised that this wasn’t a strike, based solely on the video. The horizontal stabiliser vibrates precisely at the “impact” point. I guess it could be wash from the engines?

Re the tail strike. For the PF I see a really good example of the old adage “better to be lucky than good”

Any news on crew experience ?

Quote:

Originally Posted by tubby linton

If there had been a tailstrike wouldn’t there have been a comment from atc and a runway inspection plus a local alert for the airfield. I didn’t see or hear any of that on the video.

Not necessarily. The view from the tower may not be good and may be a long way away - I haven't been in the new tower at Heathrow so don't know what things look like from there. The controller also may not be watching a particular landing aircraft that closely and would probably not note anything out of the ordinary unless sparks fly. In my experience (two occasions that I recall) it was someone in a vehicle out on the airfield that advised the tower that there may have been a tailstrike - one I was aerodrome controller, the other I was in the vehicle, on both occasions there had been a tailstrike. On a couple of other occasions I recall once where damage to the runway was reported, and another where some debris was found close to the centreline following inspections - I don't think the aircraft involved was identified to ATC on either of those occasions.

Quote:

I am however genuinely surprised that this wasn’t a strike, based solely on the video. The horizontal stabiliser vibrates precisely at the “impact” point. I guess it could be wash from the engines?

.. Tailstrike will create sparks against a dry runway.. No sparks, no strike.. Assuming there is no tailskid..

Fly safe,
B-757