Engineer decodes Air France Flight 447 emergency messages

Seattle PI.com ^ | June 8, 2009 | Andrea James

[mycloudburst]

I just finished listening to a podcast where an avionics engineer goes over the final messages sent by the Air France Flight 447 plane before it crashed.

The error messages sent by the plane show that multiple computer failures happened simultaneously, starting at 02:10 GMT, when a series of 14 warnings and failures emerged at once.

Addison Schonland, president of Innovation Analysis Group, and Michael Ciasullo, IAG's managing director of consulting services, led the podcast discussion. The engineer, who went only by Darryl, and his interviewers were careful not speculate.

Darryl is introduced as an engineer familiar with the the Honeywell ACARS system. His full name is not given because of the sensitivity over the crash, Schonland said. He does not work for Air France or Airbus.

He explains each ACARS message line by line. The ACARS is the aircraft's communications addressing and reporting system, which sends short pieces of data to other aircraft and satellites. When investigators talk of the "automatic messages" that give clues as to why the plane crashed, they are referring to the ACARS messages.

(You can see the ACARS for Flight 447 here. PDF.)

The cryptic lines contain chilling meaning.

First, the auto pilot system disengaged. Then came a basic auto flight message warning. Next, something within the flight control computer failed. Then, warning flags appeared on the personal flight displays of the captain and co-pilot. Then the rudder exceeds the limits of normal flight. And on it goes.

"With all of these failures, they don't have the information that they need to fly the aircraft in a safe environment," Darryl says. "If the pilot or first officer don't have any display functioning, then they're flying blind in the night. ... You're trying to fly the aircraft with no technology."

The last message received is a cryptic "213100206ADVISORY" warning at 02:14 GMT. It indicates loss of cabin pressure.

"There's so much going on, the pilots don't know what to do other than take a hold of the stick and fly the aircraft, because the airplane is not flying itself," Darryl said. "If this was happening in a clear day in the middle of the day, you'd still be in serious trouble, but at least you'd know if you were climbing or descending."

(Listen to the 99-cent podcast.)

Update: 11:10 p.m.: Schonland says he's making the podcast available for free as a public service.

[preacher]

Air France Bomb Threat Before Flight 447 Crash
http://www.foxnews.com/story/0,2933,524835,00.html

Brazil Detains Suspected al-Qaeda Member

A suspected al-Qaeda member has been taken into custody by Brazilian authorities in a case shrouded in secrecy, police said Tuesday.

-snip-

Brazil is home to one of the largest Arab populations outside the Middle East, with most living in Sao Paulo and in Foz do Iguacu, a hotbed of smuggling and contraband in the so-called Tri-Border region near Argentina and Paraguay.

http://www.time.com/time/world/article/0,8599,1900997,00.html

[Frantzie]

Airbus A330 = Dangerous POS

Air France should have cancelled the flight going through at least 1,000 miles of huge cumulonimbus storms. If you cannot go around - CANCEL.

[Paladin2]

That’s my current conclusion too.

[thinking]

nonsense:....that flight was a regular daily flight, flown 1000s of times....your rant is an effort to deflect from the real cause...

[the_Watchman]

I’ll insert a new speculative conjecture. Perhaps the Jihadists have developed a method to interfere with the computers on planes. The Airbus would be an inviting target since it has no hydraulic backup.

[onedoug]

Hmm....

[Paladin2]

http://blog.seattlepi.com/aerospace/library/ACARS_AF447.pdf

[commish]

Then the rudder exceeds the limits of normal flight.

To me this is the key piece of information here, especially considering that the Vertical stabilizer was found intact, and with the history of the Airbus Rudder/tail failure in NYC. I would be willing to bet when all is said and done, that in the end they will find that for whatever reason, the same type of thing happened as happened in NYC - either the pilot, the comupter or both over compensated or attempted to brute force a turn and the tail snapped off.

[Paladin2]

The last message in the PDF is that the rudder reached its limit of travel. This is consistent with the recovered tail photos showing the lower part of the rudder (which I’d guess connects with the actuator) ripped off. That could have easily been the last part of the tail attached to the plane.

[the long march]

Other planes successfully completed flights near the time this occurred. And to be accurate the Airbus A330 is not any worse than other planes out there.

[driftdiver]

So all these major system failures occurred at one time. sounds like a bomb to me.

The plane broke apart at altitude. A stall would not cause that. A serious thunderstorm could potentially but probably not.

The pilot reported turbulence but I didnt get the impression he said the plane was in danger of coming apart.

[pray4liberty]

This does not look good.

[Paladin2]

"the Airbus A330 is not any worse than other planes out there."

Not a ringing endorsement.

[visualops]

According to the above, there were several failures before the rudder message.

[bert]

I am pretty much in agreement in that a simple solution is likely correct. The proximate cause is reduced to overstress on under designed connections

[MichaelP]

The rudder snapping off, as it did in N.Y. could be consistent with an event occuring in the storm. Everyone is jumping to conclusions about it being terrorism, but it occured at a point where the plane was transiting the worst of the storm. If a bomb choose to go off at just that moment, it would be a huge coincidence.

Mike

[AussieJoe]

“I’ll insert a new speculative conjecture. Perhaps the Jihadists have developed a method to interfere with the computers on planes. The Airbus would be an inviting target since it has no hydraulic backup.”

Time to start rounding up all those computer science students of ME appearance, and the ones already working in I.T. also.... We’re going to need a bigger gitmo, MUCH bigger!

[r9etb]

So all these major system failures occurred at one time.

The article is extremely unclear on that point. It says "all at one time," and then discusses the failures in a manner that seems far more consistent with the earlier reports that they were strung out over several minutes.

I doubt that "Darryl," who has no connection with Airbus or Air France, has inside information. The "simultaneous" claim is suspect.

[r9etb]

If a bomb choose to go off at just that moment, it would be a huge coincidence.

Ahhhh, that's just what they want you to think! (/shifty eyes...)

[2CAVTrooper]

“Airbus A330 = Dangerous POS”

Has a safer record than most Boeing offerings.

[silverleaf]

the al Qaeda operative was picked up because of an FBI tip

He was held for about 6 weeks- THEN RELEASED

In terms of US effectiveness against al Qaeda- we are reliving the glorious 90’s

(BTW- KSM visited Brazil in 1995 on “vacation” at the time his bojinka plan was coming together)

[mewzilla]

FWIW....

12 similar flights deepen Air France 447 mystery

Airlines confirmed that at least a dozen aircraft departed roughly at the same time and traversed approximately the same route, but did not report problematic weather conditions.

[commish]

According to the above, there were several failures before the rudder message

exactly. The plane was in serious distress by that time, and for whatever reason be it pilot, computer, storm, or a combination there of; the airframe was put in an overstress condition and failed. Not to be dismissive of the possibility of terrorism in light of the bomb threat - it is possible a bomb could have caused the combination of failures - but it would seem that the FIRST thing to go in that case would be cabin pressure, not the last thing.

[oh8eleven]

I am pretty much in agreement in that a simple solution is likely correct.
Occam's razor - "Of several acceptable explanations for a phenomenon, the simplest is preferable" - and usually right.

[driftdiver]

true, but I still suspect a bomb. If it is we’ll never hear about it. The pattern has been to cover up terrorist attacks.

[driftdiver]

“If a bomb choose to go off at just that moment, it would be a huge coincidence.”

Not really, since there are routinely storms in that area this time of year. Also assuming there wasn’t someone on board who set it off.

[circumbendibus]

BOOKMARK

Thanks for post. Following this closely.

[Paladin2]

"Has a safer record than most Boeing offerings"

OK, I'll take a link to those data.

[expatpat]

The A330 has one set of problems that is not present in most other airplanes out there:
- it has fly-by-wire (i.e., its flight is completely controlled by computer(s)),
- there is no manual back-up to its flight control,
- the ADIRU which is part of the FBW system has had 2-3 emergency airworthiness directives placed on it in the last few months,
- a pilots union is recommending that pilots refuse to fly it.

Enough factors?.....

[PilotDave]

“but it would seem that the FIRST thing to go in that case would be cabin pressure, not the last thing”.

Don’t assume a massive explosion like Lockerbie or twa 800. That’s what most everybody envisions. It was more likely a nasty firebomb raging out of control in the cargo hold, like the Air Florida Accident. That was also a slow degradation of systems until flight controls were useless.

[Publius6961]

BUMP!

[353FMG]

“A suspected al-Qaeda member has been taken into custody by Brazilian authorities...”

.
That’s what’s wrong with the West — they allow suspected Al-Qaeda members to roam around free and only grab them after they have done the damage. Did it have to take the deaths of 228 travelers for the authorities to spring into action?

[2111USMC]

- the ADIRU which is part of the FBW system has had 2-3 emergency airworthiness directives placed on it in the last few months,

I'm willing to bet that the entire cause of this incident has to do with a failure of the ADIRU. There were documented cases of similar (but not fatal) errors on this exact system in other planes.

[D Rider]

Airbus A330 = Dangerous POS

Fly by wire. Die by wire.

[expatpat]

Agreed.

[Buckeye McFrog]

mulitple simultaneous computer failures? Sounds like Al Qaeda brought them down with a virus?

[BP2]

Notwithstanding any comments about the Airbus or thunderstorms...

Here's a VERY realistic scenario (albeit unusual and catastrophic) that may have happen (translated somewhat for non-pilots):

The A330, just like all aircraft Commercial Aircraft worldwide, must have a standby Attitude Indicator, Altimeter and Airspeed Indicator that requires no electrical power (the indicators in the CENTER of this graphic of the A330 Panel display):

The Standby Altimeter and Airspeed Indicator themselves require no electrical power to operate, as they measure the flow of air molecules in the pitot tubes (and SAS). HOWEVER, the pitot tubes DO use electrical power to stay heated and can be blocked with ice if the aircraft if the aircraft is IN any visible moisture -- AF477 may NOT have been in thunderstorms (and turbulence) as many meteorologists are now saying -- just flying through clouds. EITHER WAY, no electrical power at night over the water is NOT cool.

The gyro in the Standby Attitude Indicator (what pilots use as a back up to the electric screen in front of them to know up from down at night or in the clouds) on the A330 will continue to spin for 5 minutes. After that, if electrical power is not restore, it will begin to tumble. In that scenario, in the clouds and at night with no power, you then have only the Turn/Slip Indicator (very imprecise), Standby Altimeter and Airspeed Indicator -- and it VERY hard to fly that way for very long.

SO, imagine having electrical problems, at night, in the clouds, in the middle of the Atlantic Ocean.

You're outside of "normal" (VHF) radio range, so back-up emergency power for the standby radio wouldn't matter anyway -- although you might have a chance to squeeze off a MAYDAY call to other aircraft in the area -- if they were close enough to hear. ACARS, an automated maintenance message system, shoots off 24 messages -- it has it's own, independent power source and antenna. HF radio needs normal electrical power to transmit, so no MAYDAY calls on that radio to a receiver in Africa. You don't have time to make a radio call ANYWAY, because one pilot is flying, and the other is troubleshooting (with a checklist and a hand-held flashlight!). AVIATE, NAVIGATE, COMMUNICATE -- in that order.

The Autopilot (and auto-throttles) needs electrical power to operate, and it clicks off by default, so you just hand-fly it -- no problem. Not normally a problem if you're Day VFR, but you're at 35,000', at night, at a high airspeed. It's easy to over-control the aircraft and begin Pilot Induced Oscillation (PIO), where you are lagging behind the last input you just made to the steering yolk. Above 24,000', "Dutch Roll" is also a serious problem, where the same type of PIO can send the aircraft out of control with YAW rudder inputs -- the "yaw dampers" need electrical power, too. THAT may well be the final ACARS about the rudder, if the pilot was making aggressive rudder inputs at high altitude, after "Mach Tuck" kicks in and the aircraft's wings and elevator begins to stall near Mach 1.

So there you are -- at night, over the water (false visual horizon), maybe in the clouds (pilot tubes freeze up), at high altitude and high airspeed -- it makes it VERY difficult to keep control of the aircraft. OH! And the aircraft needs to descend as it loses pressurization (it too needs electrical power after a short while), so the pilots are descending to 10,000' because the passenger drop-down oxygen masks are only good for 15 minutes.

Your margin of error as a pilot is very small in this situation. If you let the aircraft get out of control, which is VERY realistic even for an experienced group of pilots in that situation, a few seconds later you'll have loss of aircraft control. Once the Standby Attitude Indicator starts tumbling after 5 minutes of no power -- well... it's REALLY bad.

So, I could see it being the nightmare pilot scenario of Complete Electrical Failure (and/or Fire) at night. A pilot on a track nearby thinks he saw a white fireball for about 5 seconds -- he may have seen the last moments of AF447 with a erupting electrical fire as it passed maximum strucural airspeed in descent and broke apart.

All of this is very likely and realistic nightmare scenario, based upon what we've heard up to this point ...

Airbus and thunderstorms notwithstanding -- pilots practice this scenario in the simulator several times a year, but it can never quite prepare you for the REAL THING!

[dead]

Very insightful and horrifying.

Some people are absolutely determined to label all plane crashes terrorism, though it doesn't appear the most likely scenario here.

Planes are big complicated hunks of metal that weigh many tons and rely on so much technology to stay up there. Sometimes, gravity wins.

[Frantzie]

Like I said Airbus A330 = POS.

Too many things to go wrong. Bad flight through 1,000 + miles of mega thunderstorms. If your Airbus pilot tubes freeze up at 35,000 feet then this POS plane needs to stick to 10,000 feet.

How come the little APU did not pop down to generate some power. It hs a little propeller or something.

[Frantzie]

Why did these other planes not crash that night?

[Jonx6]

I think you are thinking of an EPU.

[2CAVTrooper]

Here is one of many sites:

http://www.airsafe.com/events/models/rate_mod.htm

The A330 has racked up well over 11 million flight hours with only one fatal accident in commercial service.

The Air France flight in question had over 18,000 hours and 2,500 cycles clocked on the airframe.

“The A330 up to now had a perfect safety record with passengers on board”
http://leehamnews.wordpress.com/2009/06/01/a330-in-missing-air-france-flight/

http://www.cnn.com/2009/WORLD/americas/06/01/air.france.brazil.safety/index.html

[Jonx6]

The APU is normally a little gas turbine engine.

[Jonx6]

A RAT, that’s what we used to call the fan thing...

[BP2]

Plenty of pilots dislike the Airbus - I’m partial to Boeing and MDs myself.

However, the apu won’t work at certain altitudes and airspeeds because of compressor stall. If they were victims of multiple electrical bus fires/failures, depending on where it was in the system, an apu might not have restored power anyway.

[2CAVTrooper]

“Too many things to go wrong. Bad flight through 1,000 + miles of mega thunderstorms. If your Airbus pilot tubes freeze up at 35,000 feet then this POS plane needs to stick to 10,000 feet.”

Same thing can and does happen to Boeings.

[2CAVTrooper]

There has been issues with the ADIRU installed on Boeing aircraft too, so this isn’t just an Airbus problem.

[expatpat]

Perhaps not, but it’s my understanding that the Boeing FCS is more fail-safe than that on Airbus.

[thinking]

Quote:

According to Air France, at 02:00 GMT Monday morning the aircraft encountered stormy weather; at 02:14 GMT an automatic signal was received from the aircraft reporting that it had suffered “a failure of the electrical system” while flying through strong turbulence.

One possibility, the airline suggests, is that F-GZCP was struck by lightning. Lightning strikes are, however, common on aircraft and rarely cause any problems, let alone disaster.

In fact, all commercial airliners, including the A330, are designed and built to withstand storms, turbulence, and lightning strikes – these capabilities are required before an aircraft can be granted airworthiness certification. Their electrical and electronic systems are also screened against lightning and other forms of electromagnetic interference.

Like all Airbus airliners, the A330 employs a fly-by-wire (FBW) – that is, electronic – flight control system, employing five separate computers. Total failure of the FBW system would cause catastrophe, but is incredibly unlikely. The system is so designed that it can suffer more than one failure and stay operational. It contains computers of different designs by different manufacturers running different software, so that a particular hardware failure or software glitch or virus cannot cause the system as a whole to fail.

So the loss of this aircraft is likely to arouse significant concern across the commercial aviation industry, until such time as the cause of the accident is determined or deduced.

Unquote