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-   -   BA 321 tail strike? (https://www.pprune.org/rumours-news/644939-ba-321-tail-strike.html)

RexBanner 3rd Feb 2022 06:19


Originally Posted by Big Pistons Forever (Post 11178976)
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 ?

Amongst the more senior end of the A320 status list in both seats. Inexperience not a factor here.

finalapproach 3rd Feb 2022 07:23

"he's got it . . . he's got it" - why does the guy making the video assume it's a male pilot?

Denti 3rd Feb 2022 08:11


Originally Posted by finalapproach (Post 11179114)
"he's got it . . . he's got it" - why does the guy making the video assume it's a male pilot?

Fair question. But with just around 5% female pilots it is a fair assumption. There are airlines actively working on increasing that percentage, but it seems to be a very slow progress.

camel 3rd Feb 2022 08:45

Tea no biscuits ? or maybe Horlicks Capt ?

PJ2 3rd Feb 2022 15:16


Originally Posted by H Peacock (Post 11178369)
What’s with the inordinate delay in getting the gear up after the GA?

In the (very distant) past, from experience in the sim, I've found that most often it was the absence of the "positive climb" call, so yes, bit of startle or at least being "out of routine".

Jonty 3rd Feb 2022 16:03

Also there may have been some discussion about wether they wanted to bring the gear up. However that would be subjective given how hard the flight crew felt the touchdown was.

Consol 3rd Feb 2022 21:56


Originally Posted by Jonty (Post 11179343)
Also there may have been some discussion about wether they wanted to bring the gear up. However that would be subjective given how hard the flight crew felt the touchdown was.

I doubt there was time for much analysis. Baulked landings are demanding, only concerns are avoiding tail and pod contact (narrowly avoided there) and climbing away. Gear is a later consideration.
Everyone has done an embarrassing landing where the technique was wrong (probably in this case). Mistakes happen and they were probably a bit lucky to escape a tail scrape. Until a few years ago it wasn't on YouTube. Learn from it.

vilas 4th Feb 2022 09:26

Important thing about balked landing is after selecting TOGA, set an attitude which is below tail strike attitude and wait till the aircraft climbs away on its own. The only assistance should come in form of maintaining the configuration till safely away. It may happen after another touchdown but not to assist. Gear is the only part of the plane designed to withstand impact load so doesn't need as much care as the tail. Early gear retraction is the cause of Dubai 777 total destruction. Had the gear been down the aircraft would've come down on the gear but not written off.

3Greens 4th Feb 2022 10:30


Originally Posted by vilas (Post 11179683)
Important thing about balked landing is after selecting TOGA, set an attitude which is below tail strike attitude and wait till the aircraft climbs away on its own. The only assistance should come in form of maintaining the configuration till safely away. It may happen after another touchdown but not to assist. Gear is the only part of the plane designed to withstand impact load so doesn't need as much care as the tail. Early gear retraction is the cause of Dubai 777 total destruction. Had the gear been down the aircraft would've come down on the gear but not written off.

tail strike attitude? Hard to judge that when the gear is fully compressed after a hard bounce, but yes; if you select TOGA, the aircraft climbs away without much pitch at all initially, amd then when clear of the ground you can pitch to the SRS. Requires quite a pull on some variants.

Howzitchina 24th Feb 2022 13:08


Originally Posted by Doors to Automatic (Post 11178112)
Out of interest does anyone know why the spoilers didn’t deploy on the firmer of the first two touchdown’s. I would have thought that this would have kept the aircraft on the ground?

Spoiler Logic: something like, two wheels on ground + Spoilers Armed + Idle (or if not armed, at least one TR in Idle)


Howzitchina 24th Feb 2022 13:10

Looks like she over corrected all the way in (stirring the pot), flared high, floated.

Next.

Howzitchina 24th Feb 2022 13:12


Originally Posted by Denti (Post 11179131)
Fair question. But with just around 5% female pilots it is a fair assumption. There are airlines actively working on increasing that percentage, but it seems to be a very slow progress.

But all the videos on Youtube and TT are female pilots . . .

Fursty Ferret 24th Feb 2022 16:57


Originally Posted by Greek God (Post 11178871)
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.

Both ailerons deflects upwards with spoiler extension so not sure it would make any difference. I never felt the need to apply into-wind aileron on the A320 in real life, but our simulator model would punish you if you didn’t, particularly on a wet runway.

7478ti 4th Mar 2022 16:25

Yes, it's very important to give the flight crew the benefit of the doubt here, on performance in what appeared to be challenging weather conditions. But that said, this entire BA1307 A321 EGLL/LHR landing instability event thread appears to be missing critical assessment of key points related to FBW flight control design. Any credible assessment of this kind of an event needs to consider APC/PIO, and any potential contributing factors, regarding elements "Air-Ground Sensing" logic and state changes, flight control logic changes as a function of RA and A-G sensing, potential effects of multiple RA inputs as a function of bank angle, FBW algorithm phase margins, gain margins, and damping ratios, in both roll and pitch, possible issues of multiple side stick inputs, main gear strut extension and compressions, pitch changes due to thrust inputs or engine response, FBW pitch and bank limiting interactions, and still a host of other factors like the wind and gust environment, including the power spectral density of any gusts. Finally, DFDR and QAR data would be important to really assess how much of this event was potentially related or attributed to flight control design, versus pilot inputs, versus external disturbance effects. Do not assume this response would necessarily be the same with other types or other OEMs jets. Gusting to 31 knots, with this response? This type of an event outcome is arguably much less likely in other jet types, or other OEMs jets, due very different flight control designs, both FBW and non-FBW. I can confidently make that assertion, having previously flown many of these types in specific tests, for determination or assessment of both AFM and operational (FCOM) limiting or demonstrated conditions, over many decades.

vilas 5th Mar 2022 13:40

Airbus ground spoiler logic is a bit elaborate and has undergone changes. According to the changes introduced quiet sometime back in this case the spoilers should have deployed if they were armed. I am producing below the new SEC120 logic.
To summarize, the SEC standard 120 provides means to reduce: q Runway excursions by enabling: •Arming of the ground spoilers even when the speed brake lever is not retracted.
•Extension of the ground spoilers even with a thrust lever above the Idle position.
q Hard landings by minimizing:
•The number and amplitude of bounces by triggering partial spoiler extension at touchdown even with both thrust levers in the ATHR position.

7478ti 9th Mar 2022 04:27

Helpful information... still lots of other unknowns...

Would need to actually see the QAR or DFDR data to make any credible assessment of the fraction of responsibility to assign to design, versus crew input (or lack of input, or multiple inputs), ...or the wind/gust/shear disturbance severity (which at this point seems somewhat unlikely... because those conditions appeared to be relatively low order?)...

O:)

FlightDetent 9th Mar 2022 04:38

Under the BA monitored approach concept, how is the responsibility divided / task allocated for a baulked landing?

The video is not recognizably different to older cases where two pilots flying at the same time introduced a little PIO.



​​​

Locked door 9th Mar 2022 08:17


Originally Posted by FlightDetent (Post 11197056)
Under the BA monitored approach concept, how is the responsibility divided / task allocated for a baulked landing?

The video is not recognizably different to older cases where two pilots flying at the same time introduced a little PIO.



​​​

There is only ever one pilot flying the aircraft, P1 would have taken over below 1000ft and retains control until the engines are shut down on stand or hands the aircraft back to P2 at a suitable low workload point after the missed approach.

There’s never any control handover during high workload events, that would just be silly!

LD

FlightDetent 9th Mar 2022 10:40

So the pilot handling becomes the pilot non-landing but go-arounding. :ok:

This classic is what I had in mind.


Sure, with a touchdown and a bounce the F/CTL complexity increases diabolically.

vilas 9th Mar 2022 12:21


Originally Posted by Fursty Ferret (Post 11189648)
Both ailerons deflects upwards with spoiler extension so not sure it would make any difference. I never felt the need to apply into-wind aileron on the A320 in real life, but our simulator model would punish you if you didn’t, particularly on a wet runway.

Below is the write up about Aileron antidroop which was installed may be a decade ago.
[QUOTE] [This modification installs the aileron anti-droop function in order to improve braking efficiency during landing or Rejected Takeoff (RTO) and to allow operation on short runways. The ground spoiler function uses all spoilers and ailerons, instead of spoilers 1 to 5 only. With this modification, the ailerons extend when: - - - - - Note The ground spoilers fully extend The flight mode is in normal law The autopilot is set to OFF The flaps are not in clean CONF The pitch attitude is below 2.5°. : When the ground spoilers are partially extended, the ailerons do not extend. With this modification, the ailerons retract when the ground spoilers retract or when the aircraft attitude is higher than 2.5°, whichever occurs first. /QUOTE]


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