Flight data from AF447 crash

[CCIP]

So, the investigators have released a statement about what they found on the flight recorders of Air France 447 that they pulled out from the bottom of the sea. You can find the full statement here:

http://www.bea.aero/fr/enquetes/vol....mai2011.en.pdf

What do you make of it?

Sounds like a classic crash scenario - a bad combination of several factors conspiring against the plane. Bad weather + failing airspeed readings + erroneous pilot responses based on that readings = unrecoverable stall.

[Torplexed]

Sounds like two pilots overwhelmed by all the bells and whistles in the modern cockpit. In the last two decades we've moved toward having computers flying the jet, with pilots at the receiving end of electronic commands rather than the other way around.

US Airways Captain Sullenberger III, who flew an Airbus A320 in his "miracle" Hudson River landing two years ago, said in an interview that automation is a "mixed blessing." While computerized planes are capable of protecting a pilot, they can also produce other types of errors that would likely not have occurred in an older jet.

[AVGWarhawk]

Sullenberger's landing imo was not a miracle. The landing was accomplished by capable hands and one who understands the dynamics of his aircraft.

Having some trouble downloading the PDF.

[GoldenRivet]

Originally Posted by AVGWarhawk

Having some trouble downloading the PDF.

ditto, it freezes up.

my opinion for whatever it's worth.

Supercooled water rapidly froze and overwhelmed the pitot static heating elements for a long enough period of time to cause this disaster.

this caused an autopilot disconnect, and numerous bells and whistles. chances are the pilots became completely overwhelmed by the sudden influx of data.

the NOVA series on this accident >>> http://www.amazon.com/Nova-Crash-Fli.../dp/B003WKQ450 <<< i think has the cause completely nailed down, and certainly makes its case well.

[CCIP]

Originally Posted by AVGWarhawk

Sullenberger's landing imo was not a miracle. The landing was accomplished by capable hands and one who understands the dynamics of his aircraft.

Also, at least from what I'd read/seen, actually Airbus automation deserves some credit in that landing as well. The stall protection system had actually helped to fly the aircraft into the water at minimum possible speed/maximum safe angle of attack without stalling, something that would be much more difficult to do purely by hand. It left the pilots much better able to concentrate on making crucial decisions at hand, without getting swamped by details.

[Herr-Berbunch]

Accident to the Airbus A330-203
flight AF 447 on 1st June 2009
Update on Investigation
www.bea.aero
27 May 2011
SPECIAL FOREWORD TO ENGLISH NOTE
This note has been translated and published by the BEA to make its reading easier for Englishspeaking
people. As accurate as the translation may be, the original text in French should be
considered as the work of reference.
History of Flight
On Sunday 31 May 2009, the Airbus A330-203 registered F-GZCP operated by Air France was
programmed to perform scheduled flight AF447 between Rio de Janeiro Galeão and Paris
Charles de Gaulle. Twelve crew members (3 flight crew, 9 cabin crew) and 216 passengers
were on board. Departure was planned for 22 h 00(1).
At around 22 h 10, the crew was cleared to start the engines and to leave the parking space.
Take-off took place at 22 h 29. The Captain was PNF, one of the co-pilots was PF.
The take-off weight was 232.8 t (for a MTOW of 233t), including 70.4 t of fuel.
At 1 h 35 min 15 ---61580;, the crew informed the ATLANTICO controller that they had passed the
INTOL point then announced the following estimated times: SALPU at 1 h 48 then ORARO at
2 h 00. They also transmitted the SELCAL code and a test was undertaken successfully.
At 1 h 35 min 46, the controller asked the crew to maintain FL350 and to give their estimated
time at TASIL.
At 1 h 55, the Captain woke the second co-pilot and said "[…] he’s going to take my place".
Between 1 h 59 min 32 and 2 h 01 min 46 ---61581;, the Captain attended the briefing between the
two co-pilots, during which the PF said, in particular "the little bit of turbulence that you just saw
[…] we should find the same ahead […] we’re in the cloud layer unfortunately we can’t climb much
for the moment because the temperature is falling more slowly than forecast" and that "the logon
with Dakar failed". The Captain left the cockpit.
The airplane approached the ORARO point. It was flying at flight level 350 and at Mach 0.82
and the pitch attitude was about 2.5 degrees. The weight and balance of the airplane were
around 205 tonnes and 29% respectively. Autopilot 2 and auto-thrust were engaged.
At 2 h 06 min 04, the PF called the cabin crew, telling them that "in two minutes we should enter
an area where it’ll move about a bit more than at the moment, you should watch out" and he
added "I’ll call you back as soon as we’re out of it".
(1)All times
are UTC.
At 2 h 08 min 07 ---61582;, the PNF said "you can maybe go a little to the left […]". The airplane began a
slight turn to the left, the change in relation to the initial route being about 12 degrees. The level
of turbulence increased slightly and the crew decided to reduce the speed to about Mach 0.8.
From 2 h 10 min 05 ---61583;, the autopilot then auto-thrust disengaged and the PF said "I have the
controls". The airplane began to roll to the right and the PF made a left nose-up input. The stall
warning sounded twice in a row. The recorded parameters show a sharp fall from about 275 kt
to 60 kt in the speed displayed on the left primary flight display (PFD), then a few moments
later in the speed displayed on the integrated standby instrument system (ISIS).
Note 1: Only the speeds displayed on the left PFD and the ISIS are recorded on the FDR; the speed
displayed on the right side is not recorded.
Note 2: Autopilot and auto-thrust remained disengaged for the rest of the flight.
At 2 h 10 min 16, the PNF said "so, we’ve lost the speeds" then "alternate law […]".
Note 1: The angle of attack is the angle between the airflow and longitudinal axis of the airplane.
This information is not presented to pilots.
Note 2 : In alternate or direct law, the angle-of-attack protections are no longer available but a
stall warning is triggered when the greatest of the valid angle-of-attack values exceeds a certain
threshold.
The airplane’s angle of attack increased progressively beyond 10 degrees and the plane started
to climb. The PF made nose-down control inputs and alternately left and right roll inputs. The
vertical speed, which had reached 7,000 ft/min, dropped to 700 ft/min and the roll varied
between 12 degrees right and 10 degrees left. The speed displayed on the left side increased
sharply to 215 kt (Mach 0.68). The airplane was then at an altitude of about 37,500 ft and the
recorded angle of attack was around 4 degrees.
From 2 h 10 min 50, the PNF tried several times to call the Captain back.
At 2 h 10 min 51 ---61584;, the stall warning was triggered again. The thrust levers were positioned
in the TO/GA detent and the PF maintained nose-up inputs. The recorded angle of attack, of
around 6 degrees at the triggering of the stall warning, continued to increase. The trimmable
horizontal stabilizer (THS) passed from 3 to 13 degrees nose-up in about 1 minute and
remained in the latter position until the end of the flight.
Around fifteen seconds later, the speed displayed on the ISIS increased sharply towards 185 kt;
it was then consistent with the other recorded speed. The PF continued to make nose-up
inputs. The airplane’s altitude reached its maximum of about 38,000 ft, its pitch attitude and
angle of attack being 16 degrees.
Note: The inconsistency between the speeds displayed on the left side and on the ISIS lasted a little less
than one minute.
At around 2 h 11 min 40 ---61585;, the Captain re-entered the cockpit. During the following seconds,
all of the recorded speeds became invalid and the stall warning stopped.
Note: When the measured speeds are below 60 kt, the measured angle of attack values are considered
invalid and are not taken into account by the systems. When they are below 30 kt, the speed values
themselves are considered invalid.
The altitude was then about 35,000 ft, the angle of attack exceeded 40 degrees and the vertical
speed was about -10,000 ft/min. The airplane’s pitch attitude did not exceed 15 degrees
and the engines’ N1’s were close to 100%. The airplane was subject to roll oscillations that
sometimes reached 40 degrees. The PF made an input on the sidestick to the left and nose-up
stops, which lasted about 30 seconds.
At 2 h 12 min 02, the PF said "I don’t have any more indications", and the PNF said "we have
no valid indications". At that moment, the thrust levers were in the IDLE detent and the
engines’ N1’s were at 55%. Around fifteen seconds later, the PF made pitch-down inputs. In
the following moments, the angle of attack decreased, the speeds became valid again and the
stall warning sounded again.
At 2 h 13 min 32, the PF said "we’re going to arrive at level one hundred". About fifteen seconds
later, simultaneous inputs by both pilots on the sidesticks were recorded and the PF said "go
ahead you have the controls".
The angle of attack, when it was valid, always remained above 35 degrees.
The recordings stopped at 2 h 14 min 28. The last recorded values were a vertical speed of
-10,912 ft/min, a ground speed of 107 kt, pitch attitude of 16.2 degrees nose-up, roll angle of
5.3 degrees left and a magnetic heading of 270 degrees.
New findings
At this stage of the investigation, as an addition to the BEA interim reports of 2 July and 17
December 2009, the following new facts have been established:
---136;. The composition of the crew was in accordance with the operator’s procedures.
---136;. At the time of the event, the weight and balance of the airplane were within the operational
limits.
---136;. At the time of the event, the two co-pilots were seated in the cockpit and the Captain was
resting. The latter returned to the cockpit about 1 min 30 after the disengagement of the
autopilot.
---136;. There was an inconsistency between the speeds displayed on the left side and the integrated
standby instrument system (ISIS). This lasted for less than one minute.
---136;. After the autopilot disengagement:
---132;.the airplane climbed to 38,000 ft,
---132;.the stall warning was triggered and the airplane stalled,
---132;.the inputs made by the PF were mainly nose-up,
---132;.the descent lasted 3 min 30, during which the airplane remained stalled. The angle of
attack increased and remained above 35 degrees,
---132;.the engines were operating and always responded to crew commands.
---136;. The last recorded values were a pitch attitude of 16.2 degrees nose-up, a roll angle of
5.3 degrees left and a vertical speed of -10,912 ft/min.



Bureau d’Enquêtes et d’Analyses pour la sécurité de l’aviation civile
Zone Sud - Bâtiment 153 - 200 rue de Paris - Aéroport du Bourget - 93352 Le Bourget Cedex FRANCE
T. : +33 1 49 92 72 00 - F : +33 1 49 92 72 03
www.bea.aero

[CCIP]

Yeah, the nose-up inputs is what I referred to as the apparent erroneous response to the situation. Sounds like in the end, it was the PF's input which stalled the plane. Probably caused by massive disorientation, of course.

By the way, for those of you familiar with Airbus systems, what would've caused the plane's controls to go into Direct Law? Would that be the loss of airspeed readings?

[AVGWarhawk]

Originally Posted by CCIP

Also, at least from what I'd read/seen, actually Airbus automation deserves some credit in that landing as well. The stall protection system had actually helped to fly the aircraft into the water at minimum possible speed/maximum safe angle of attack without stalling, something that would be much more difficult to do purely by hand. It left the pilots much better able to concentrate on making crucial decisions at hand, without getting swamped by details.

But again, I refer back to the pilot knowing his aircraft. Scully worked with the aircraft and what the aircraft electronics can perform/capable of doing. I still stand by my capable hands statement but would like to add cool head in this situation.

[CCIP]

Oh, by all means. Would never take the credit away from the pilot - in the end, it's his decisions and skills that saved the day, the plane only helped a little

[AVGWarhawk]

Originally Posted by CCIP

Oh, by all means. Would never take the credit away from the pilot - in the end, it's his decisions and skills that saved the day, the plane only helped a little

What is interesting and a good question, do pilots get completely dependent on the aircraft electronics to the point of not being able to handle a situation such as this Air France disaster? In other words, do they become complacent in the routine? I understand most airline companies test and retest pilots. Training is ongoing.

[MH]

Looks similar to this disaster?

[CCIP]

Originally Posted by MH

Looks similar to this disaster?

Actually this one's the completely opposite. In this old scenario, it appears that the stall protection system worked TOO well, and decided that it knew better than the pilot what the airplane was doing, pitching down to increase airspeed and maintain altitude when the pilot input was to try and pull the plane up. Although the pilot did perform the maneuver without adequate preparation and with too low a safety margin.

On the surface, this AF disaster looks like the opposite - the instruments and stall protections failed completely, the airplane's systems had nothing to offer the pilot, and the pilot got confused and flew the airplane into a stall by pitching up - and the plane did exactly what the pilot asked it to do.

[AVGWarhawk]

Not really, no.

[Jimbuna]

Originally Posted by AVGWarhawk

What is interesting and a good question, do pilots get completely dependent on the aircraft electronics to the point of not being able to handle a situation such as this Air France disaster? In other words, do they become complacent in the routine? I understand most airline companies test and retest pilots. Training is ongoing.

That's an excellent question actually and one I doubt an airline would want to answer for fear of future claims against it.

Personally, I think it should be a mix of the two but the pilot should always have the ability to override the electronics should he feel it necessary.

[mako88sb]

There's been a ongoing discussion of this incident since it happened over at Airdisaster.com;

http://forums.jetphotos.net/showthread.php?t=49818