It looks like you're using an Ad Blocker.

Please white-list or disable AboveTopSecret.com in your ad-blocking tool.

Thank you.

 

Some features of ATS will be disabled while you continue to use an ad-blocker.

 

Crucial 'memory unit' from 2009 Air France crash recovered

page: 3
11
<< 1  2   >>

log in

join
share:

posted on May, 27 2011 @ 01:31 PM
link   
BTW EICAS in Boeing is ECAM in Airbus.




posted on May, 27 2011 @ 01:36 PM
link   
reply to post by JakiusFogg
 


THANK you.....I have to bone-up on Airbus terminology and acronyms. Have some A-330 schematics down-loaded, on my hard-drive. So, can refer to them (and teach myself....since, never flew the darn things...).


BTW....from MSNBC.......the Captain was on crew rest.....when the accident sequence began.

It is hard to come, from the rest break, and get "spooled up".....sad that the two up front were so incompetent, (apparently).


And, to add....a few abbreviations in the report.....need to point out. Because, while (whilst) second-hand normal to some, not obvious to others):

PNF = "pilot not flying"

PF - "pilot flying"

Every flight (except those rare, very LONG flights, where there are complete TWO crews....one crew for the first half, second for the last) has a designated "flying pilot" according to seat position......for example, if the take-off was the Captain's....it is his "leg"....and, when he (Captain) is on mandated crew rest (because of the flight time....in USA, over eight hours) ....then the 'relief' pilot will occupy HIS (her) seat....but, IF was Captain's leg, then the First Officer will be "Pilot Flying" (PF) in his(her) absence.

IF the First Officer has this leg, then it works similarly. The "relief" pilot (and , terms vary, among airlines) who fills in, for crew rest requirement rotations, is NEVER one of the Pilots Flying (PF). At least, at my airline.....that is the protocol.....








edit on Fri 27 May 2011 by weedwhacker because: (no reason given)



posted on May, 27 2011 @ 03:47 PM
link   
reply to post by weedwhacker
 


Thanks for that "PF"/"PNF" explanation.


Now, could you please "translate" what the report says, so anyone without any knowledge of out to fly an aeroplane can get an idea of what happened, according to that report?

Thanks in advance.



posted on May, 27 2011 @ 03:51 PM
link   
reply to post by JakiusFogg
 


I heard this on the radio this morning, and they said that what probably happened was that both pilots got confused by the information from the not working pitot tube.



posted on May, 27 2011 @ 05:40 PM
link   
On the note about the pitot tubes.

Yes units where fitted that were known to have an issue with the heating element, insufficient to protect them against ice build up. There was maintenance action in progress in the fleet to resolve this. This was not donw on this aircraft. However this alone should not have brought the plane down. correct application of thrust and attitude will stabilize the aircraft sufficiently so they have time to figure the issue out. however this is a contributory probable cause, and not yet fact.

ON the report itself this is a sort of translation as best can

020146 - Pilot have hand over brief with co pilots informs cabin crew about turbulence and leaves the cockpit to go to crew rest. - this is normal.

FL350 (35000 ft) M0.82

020807 - turns left 12 degrees from planned course (probably to avoid a reallt nasty area)

021005 - Autopilot and auto-thottle disengage - this happens when the rock and roll is too bad, and the plane says. Over to you chum. hard right turn and nose up. speed indication drops from 270kts to 60kts (icing on pitot???) or wind buffeting. the plane gives off a stall warning. twice.

021016 - Pilot declares alternate law due to "lost speeds" this means that the aircraft is not operating normally and they have reduced protections. note this is NOT reduced control. just system protection. the plane pitches up to above 10 degrees nose up, and starts to climb, rolling left to right. then indicated speed increases to 215kts at 4 degrees nose up, with verticle speed at 700 fpm (reduced from 7000 fpm)

(this is why I question the iced pitot theory, why would the IAS go and then come back if it was blocked?)

021050 - PF calls the Captain.

021051 - Stall warning and pilot engages TOGA (Take off Go Around) this is PULL POWER with 6 degrees nose up and increasing. The THS (Trimmable Horizontal Stabilizer( the to small wings at the back)) move from 3 to 13 degrees nose up. meaning they are pointing down 13 degrees.

there is a part missing here

021106 - speed INCREASES to 185 kts (it was 215kts at 021016, so what happened to the speed at 021051?) PF continues nose up inputs on the control stick (why?) with nose up at 16 Degrees.

021140 - Captain enters the cockpit - a few seconds later all air speeds become invalid (meaning reading less than 60kts and angle of attack is ignored by the system) (icing here??) but for speed values to be invalid they have to be reading less than 30kts.

The aircraft is now at FL350 (35000) with angle of attack in excess of 40 degrees with vertical speed at -10000 fpm. (near free fall speed) pitch was not more than 15 degrees. meaning he is well outside the flight envelope.again oscillating left and right up to 40 degrees each way.

021202 PF and PNF declare that reading are invalid. AT this point the thrust is set to IDLE!

This is what makes me believe that he though he was diving. high vertical speed down, and constan nose up inputs. setting the thrust to idle, to help slow him down, or at least not get any faster. Possible reason, he was worried about going "over-speed" a common worry when you don't really know how fast you are. as you might tear off the wings.

At this time, he pushed the nose down, speed increased and readings became valid again. But because the speed being invalid had caused the stall warning to stop, once it became invalid the stall warning started again!

021332 a pilot noted that they were about to reach 10000 ft. both control stick move in the same direction and the PF said "go ahead you have the controls"

This is consistent with the procedure in Airbus to transfer priority control from one stick to another. IN this case I believe Priority left. meaning, I think, the Captain was back in the seat, and taking control.

angle of attack, when valid, remained above 35 degrees. if the pitch never went above 15 degrees then never made it out of the deep stall, or even came close to it.

recording stops at 021428.They hit the water at 10900 fpm vertical speed. slight nose up and slight roll to one side.

On a personal note, people will assume and call this pilot error, in fact they are already starting. However this situation is not the first time, spacial disorientation, which is probable in this case, has occurred. Not knowing for sure what your plane is doing, and with blackness out of the windows, you have no real point of reference. Coupled with the feeling that you can't trust your instruments, and you body telling you one thing is happening, when something entirely different is happening. it is a nightmare scenario. Not their fault at all. And I feel deeply for them, in what they had to try and deal with. May this never happen again.



posted on May, 27 2011 @ 07:39 PM
link   
reply to post by JakiusFogg
 


Thing is.....any of the airspeed recorded data is suspect, as to accuracy.

We will want to focus on the pitch and power (thrust settings). To ascertain whether (and when) the aerodynamic stall actually occurred.

The level of turbulence will have to be taken into account.....accelerometer readings can be included, to (hopefully) estimate gust forces, and even direction.

And, no....an overspeed will not (sorry) "tear off the wings".....they are built much better than that.....



edit on Fri 27 May 2011 by weedwhacker because: (no reason given)



posted on May, 27 2011 @ 08:05 PM
link   
I really hope it wasnt the pitot tubes. I seem to remember there was a high profile crash with them being involed where they were iced over.

I thought they would of sorted that problem out by now.



posted on May, 28 2011 @ 02:11 AM
link   
reply to post by weedwhacker
 


Yeah, but it gets the point across in this setting. but I'm sure you'll know that prolonged overspeed in a nose down attitude can lead to catastrophic structural failure.

As for the power settings. it could be in the third stall warning, they hit the alpha protection and as they had not taken control of thrust settings, the aircraft kicked straight to TOGA. However the telling point is that just a little time later the thrust levers were at idle with engine speed at 55% n1

We still have to wait for the final full report, as this update just brings more (specific) questions.
edit on 28/5/2011 by JakiusFogg because: (no reason given)



posted on May, 28 2011 @ 02:14 AM
link   
reply to post by NumberEight
 


it has been now. After the crash EASA issues the AD 2009-0195 which mandated within a fixed time the replacement of the probes.

It is also worth noting that NOT ALL A330 even before this were affected by this condition as they had different probes installed since production. But by now this should be fixed.



posted on May, 28 2011 @ 11:27 AM
link   
reply to post by JakiusFogg
 


See......this is why I need, still, to learn up on the Airbus, and the designers' thought processes.

The Alpha Speed floors, and the AutoThrottles *always* ready to engage....on Boeings, they won't unless you physically have the A/T switch(es) in "Arm", and not "Off". There is no auto TOGA, either (unless, maybe on the 777 or on the 787, IF Boeing decided to add the software).

So...if TOGA engaged in auto, then later N1 were 55%, this indicates a pilot action on the thrust levers, and likely they clicked the A/T disconnect buttons. I would guess that, at altitude (Flight Levels) to maintain cruise airspeed, and altitude, would need around 75 to 85 % N1....55% is getting down around just above Flight Idle speed......probably 35 - 40% with levers at idle....



posted on May, 28 2011 @ 10:07 PM
link   
I would agree that after the FDR reports 100% n1 at one point then less than a few minutes later it is idel detent and 55% n1

The engines were responding to inputs. So the question remains. ...... why?

Still a mystery.



posted on May, 29 2011 @ 12:19 AM
link   
reply to post by JakiusFogg
 


YES!!!...indeed........



new topics

top topics



 
11
<< 1  2   >>

log in

join