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Guest fullflapsplease

Strange flap arrangement and spoiler deployment.

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Guest fullflapsplease

Hi guys, watch this video of a BA 744 landing at LHR, note the distinct lack of flaps and that not all the boards pop up on touchdown.It seems to me that the spoilers were manually operated?Any r/w pilots shed any light on it please?http://www.flightlevel350.com/aviation_video.php?id=6186Thanks.Mark.747400.jpg

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Guest andyman

The pilots probably used flaps 25. The outboard flaps don't extend as far as the inboard flaps. And with the spoilers, Yes there was a lengthly time between touchdown and extension. It looks like the spoilers were put in flight detent(but i don't have my PMDG to check right now). I bet the Air/Ground sensor malfunctioned.

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I agree most probably a flap 25 landing although I would have thought with minimum runway occupancy times at Heathrow a flap 30 landing would have been used in order to pull up and turn off quicker. Without seeing the inboard flaps it is harder to tell. The aircraft air/gnd logic is determined by the main gear tilt sensors. There is also a squat switch on the nose leg for stall warning and nose gear steering operations.It is not uncommon for the ground spoilers to not deploy or to get confused especially with a smooth landing or landing on a wet runway or if the aircraft tyres touch down but the aircraft ballons slightly so that the oleo legs are not compressed and therefore the gear tilt is sort of in limbo. A number of times I have seen the speedbrake lever deploy automatically then change it's mind and go back to the stowed (or nearly stowed position) and then deploy again (that system must have been designed by a woman). Quite often good ole manual intervention is required and a helping hand needed. Getting back to the video it would appear that the speed brake lever was either not armed or there was confusion with the air/gnd logic. If you look closely you will see that the spoilers deploy after selection of reverse thrust. If the spoilers were not armed then when reverse thrust levers 2 or 4 are pulled up to the idle detent the speed brake lever is raised out of the down detent and driven to deploy. This all takes time and would explain the slow deployment after touch down. The panels still seemed remarkably slow to operate all the same.CheersSteve


Cheers

Steve Hall

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Yes looks like a manual deployment,the spoilers go initially to the flight detent the the rest of the spoilers come out after a short delay.don`t know really, BA are a funny bunch.Jon

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and another thing!it really gets on my nerves when cabin crew are making PAs during the landing roll, its still too early they should wait till the aircraft is clear of the runway. They say every landing is a controlled crash,they should be alert for something going wrong during the rollout not doing PAs.Any emergency PA from the flight deck will override the cabin PA but i still think its bad form. sorry for the rant, probably misplaced on this forumjon

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Guest andyman

>and another thing!>it really gets on my nerves when cabin crew are making PAs>during the landing roll, its still too early they should wait>till the aircraft is clear of the runway. They say every>landing is a controlled crash,they should be alert for>something going wrong during the rollout not doing PAs.Any>emergency PA from the flight deck will override the cabin PA>but i still think its bad form. sorry for the rant, probably>misplaced on this forum>>jonMeh a flight attendants experiences a bagillion landings, 99.99% of which are safe landings. They expect the landing to be fine unless the captain Ding-da-ling-dong's them(or alerts the passengers). Besides, the flight attendants don't really have that great of a view from their seat to determine whether they have turned off the runway. They probably decide when to start yappin' the second their stomachs alert them that the plane has slowed down enough.

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BA use flap 25 as standard on 747s AFAIK. They had problems with cracks in the flap tracks on the 747 Classics, so stopped using flap 30 unless necessary. The UK CAA used to insist on stalling each aircraft at Flap 30 on every flight test, which may have contributed to the cracking problem.If the air/ground logic was confused, the speedbrake lever would only go to the flight detent, hence ground spoilers will not deploy when reversers are operated. Possibly as airspeed decreased, the increased weight on wheels made the ground sensing logic activate properly, thus allowing ground spoilers to deploy.Regarding FAs making PA announcements during roll-out, I can't see a problem, though the ritual "Welcome to London and thank you for flying with BA" does get a bit wearing. If the aircraft makes it to the runway safely with no previously detected problem what are the chances of there being an emergency during roll out apart from complete brake failure (highly unlikely)?Kevin


ki9cAAb.jpg

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