expat wrote on Jun 4^th, 2009 at 6:48pm:


Surely a modern aircraft still has the ability to run at least one radio (ie a VHF box) even with a "complete" electrical failure. It'd be a backward step if it couldn't - I assume the A330 has a RAT of some description.

C wrote on Jun 10^th, 2009 at 9:19am:


The-Black-Sheep wrote on Jun 10^th, 2009 at 11:04am:



If as beleived at the moment, the aircraft was breaking up in the air, then the rat would probably be one of the first things to be ripped off. It also has a max speed deployment. However, next twist to the story

Matt

I find it hard to believe it was terrorism to be honest. If ACARS sends out information stating that the aircraft was suffereing numerous faults, then we're surely not looking an explosive device taking it out. It would have just disappeared without ACARS sending any info what so ever.

With another recent "discovery" saying the aircraft was flying too slow, is it possible that it had stalled after flying into this thunderstorm (severe turbulence affecting the airspeed), then the stall becoming unrecoverable, maybe slipped into a dutch roll, ACARS sends out all this information about systems being affected while it's "falling" out of the sky, and because of the sheer forces being acted upon the aircraft, it breaks up. Wind then might have helped spread aircraft pieces over a large stretch of ocean.

Just a theory, I'm sure Matt might be able to point out if there is any flaws with it, but it's just an idea I guess.

Alec

Seems to be just a matter of finding the black boxes now and listening to what the guys on the flight deck said when it all went incredibly wrong.

Alec

Just a question but shouldnt a airline captain be able to tell if their going to fast or slow without the airspeed indicator working, i mean it would show on the GPS units with distance traveled, Ive never flown in IFR conditions like the airbus but even then it seems to me you would be able to tell if the airspeed indicator was acting weird and even then you could probably balance the speed out

DaveSims wrote on Jun 10^th, 2009 at 10:08pm:



Aerodynamically in a stall, the rudder play very little part in an Air Bus. An Air Bus stalling at 35000 feet in reality is no big problem. This is due to the aerodynamic design of the tail. When the aircraft enters a stall, the air flow over the tail actually forces the nose down. It is a feature of all Air Bus aircraft. The aircraft then descends in a gentle swoop down and then when the nose starts to rise, the tail forces it down and the whole process starts again. However, stalling a modern airliner is quite hard. Regardless of what the computers are telling you, the seat of your pants should always be a good indicator. The wing design of Air Bus's (in fact all modern aircraft) will have the wing begin to stall at the wing root. This ensures that the lateral control of the aircraft is not lost by keeping the ailerons out of the stall. During the stall of the wing root, the aircraft will be subject to pre stall buffet, also designed to start in the design of the wing early enough to give the pilot a mechanical feel through his backside. With the Air Bus a bit of over kill because aerodynamically regardless of the computers, an Air Bus is self recovering in a stall. The pilot if he wanted to, could take his hand off the stick and she would do all the work herself to recover. This is not a well know fact about Air Bus, but as I have just spent a week studying Air Bus aerodynamics, I can tell you it is true.

Matt

Hagar wrote on Jun 11^th, 2009 at 4:43am:



That is the whole idea behind this aerodynamic design. If the entire fly by wire system failed then the aircraft can be flown by differential thrust alone. We have seen with for example with the Soux City crash that it was possible with a DC 10, but it is designed into the Air Bus not to be possible, but to be able to do it. This is one of the reasons why the flying control surfaces are aerodynamically neutral. Without power, they droop on the ground, but in the air without power they go naturally neutral with the airflow and cannot freeze in an up or down position. Can the pilot over rule, the answer is a big NO! Against this, outside of one very public accident, when have the computers got it wrong agaist the rather large number of pilot error accidents? As for the pitot tubes going tits up, for start there is not just one. The pilot has one, the co-pilot has one and then they have a standby. It cannot boil down to just a pitot failure. The right and left systems are separate as is the standby system. What is common to the three systems is pitot heating, but even that has different channels. Without the CDR and CVR it is just speculation and window dressing by anyone who decides to replace fleet wide pitot tubes.

Matt

DaveSims wrote on Jun 11^th, 2009 at 9:08am:


OK, my misunderstanding, however this aircraft was only four years old and the attachment points post NYC aircraft were changed so that this failure could not happen again. In service aircraft have a large point in the pilots note about over use of the rudder as modification is not possible as it is a structure redesign for newer aircraft. However, all this still does not tell us how three independent systems failed at the same time. After all that is why we have three, to make this eventuality not possible

Matt