Skip to comments.Air France Disaster – Focus On Airbus Air Data Inertial Reference Unit (ADIRU) System
Posted on 06/03/2009 9:12:38 AM PDT by luckybogey
The Air France disaster should be watched very closely as there are numerous political implications in the aircraft industry. The Australian is reporting investigators may be looking at the Airbus Air Data Inertial Reference Unit (ADIRU) System that sent a Qantas A330 on a wild ride over Western Australia last year.
The Qantas incident last October, and another in December last year also involving an Airbus 330 near Western Australia, involved a problem with a unit called an air data inertial reference unit, which prompted flight control computers to twice pitch down the nose of one of the jets.
Fast action by the crew limited the extent of the plane's fall but 14 people were seriously injured.
The incidents raised questions about a potential wider problem with ADIRUs, which collect raw data on parameters such as air speed, altitude and angle of attack, and process the information before sending it to flight computers. They led to European authorities issuing a global alert to A330 operators.
After the Air France disaster, The Seattle Times reported yesterday that experts were already examining these malfunctions...
(Excerpt) Read more at theaustralian.news.com.au ...
I wonder how much computer data the A330 can burst to Air France as the disaster was happening. I think it can send data via satellite.
Some A330 pilots hashing this around would be very interesting.
Nobody was killed during the first two incidents...now some were. Maybe they’ll do something about it now...
At 35,000 feet the pilots would have time to recover from a nose pitch down, wouldn’t they? They can override?
Aviation Ping List
Air France Flight 447:
A detailed meteorological analysis
Gee, I think I’ll stick with Boeing.
You're assuming that the problem really is with the ADIRU. However, there's an easier explanation based on the storms in the area at the time:
A former A330 pilot said yesterday that strong turbulence mentioned by the Air France captain in his last message could have been responsible for the aircraft breaking up if load limits on the plane had been exceeded.
"When you're going through the edge of the (storm) cell, you can sometimes go from a sudden downdraft to a sudden updraft," he said.
It seems more likely than a one-off failure that's never been seen before. (Note that the Qantas failure was on a different unit made by a different manufacturer.)
Air France Bomb Threat Before Flight 447 Crash
My understanding is the plane’s data was being provided back to Air France data center including the malfunctioning systems up to the time of the event.
I’ve been sailing on the ocean (done a few major trans ocean passages) and I have vast respect for “mere” thunderstorms. I’ve been hit by line squalls with 60+mph wind at the deck that went from zero to sixty plus in bare seconds, driving white water in front. I assume this is the result of a microburst hitting the ocean surface, or something similar. Hail, twisting shifting wind blasts, etc.
The winds at 35,000’ must be even worse. What can a pilot do if confronted with a line of storms hundreds of miles across, and over 50K’ high? Look for a “sucker hole?” Go hundreds of miles around?
If flying straight into one of those walls of storms, I would not rule out ANYTHING, including flying directly into up and down drafts of over 100 knots, accompanied by golfball sized hail and lightning.
I think that sometimes, modern transoceanic jets are just going to fly into something that can destroy anything with wings.
Just an ocean sailors opinion. At those times that I’ve experienced this type of “out of nowhere” storm fury from “mere” thunderstorms, I’ve been mighty glad I was in a 48’ steel-hulled vessel, and not up in the sky in an aluminum or carbon fiber tube.
God bless the pilots who must wrestle with such monsters. They can kill you, don’t doubt it.
An Airbus mechanic/engineer called into Dennis Prager yesterday, and this “override” question came up. It seems that fly-by-wire Airbuses only have a limited ability to override. The computers really do fly the plane. THey depend on great robustness and redundancy, but in the end, the computer will do what it thinks it must, regardless of pilot input.
At least, that’s what I heard the guy tell Dennis Prager.
On the aircraft I’m most familiar with (primarily business-jets), it’s a regulatory requirement that the pilot be able to physically overpower the autopilot and its associated actuators in the case it runs away and tries to go hard-to-the-stops in any particular direction.
The flight test to demonstrate this capability involves:
1. Warn the pilots (who are expecting it; it’s a planned test flight) ... Three ... Two ... One ... Now!
2. Pilots wait two seconds to simulate how long it would take to recognize the hardover were it was unanticipated.
3. Pilots override controls to recover.
The problem the AF447 guys may have run into is that they had a hardover, but due to the turbulence didn’t recognize it until they were significantly diverted from straight-and-level. If at the same time they lost instruments, they wouldn’t have known what to do to recover even if they did recognize it.
For the best analysis of the possible cause of the incident, please go to http://www.weathergraphics.com/tim/af447/.
Superb analysis with detailed information.
I highly recommend.
At least, thats what I heard the guy tell Dennis Prager.
The override needs teleprompters.
Give me Boeing or I ain’t going.
"the planes involved in the Australian incidents were the bigger A330-300s, rather than the 200 series involved in the Air France disaster, and it is understood their ADIRUs are made by a different manufacturer"
I heard the same thing but I wondered how much data the system can send. I guess a human looking at the gauges and the weather would tell them even more. Sad.
I don’t know anymore. The 330 seems to have as impressive a safety record as possible. If you don’t count the test flight accident, you have 3.3 million flights w/out a fatality. We also don’t know the cause of this one yet and whether it will be attributed to the plane. Prior to this you had the 7 test flight fatalities and that’s it over 15 years. I don’t choose to fly Airbus planes for different reasons than safety but will fly them as needed.
Depends. The weather was bad. And even in good weather there are no guarantees, but read this about some of the luckiest people ever to get off a plane in one piece...
Easier said than done. I live in Columbus, a city of 800,000 and when I go to Boston or NYC it's almost always on an Embraer or a CRJ.
Indeed. As a real fair weather sailor with limited eperience I have only been caught in one bad open water storm and that was in a RHIB in the persian gulf long ago.
Weatheris a killer at all levels. Wonder why the pilots weather radar didn’t warn him ?
Just a look at such would be enough to divert the flight plan to smoother skies or return to Brazil
Rule #4: Thou shall not fly into thunderstorms. I will not fly within 20 miles of an active building cell. There are old piliots, and there are bold pilots. There are no old, bold pilots.
I am an old chicken pilot.
The suspected flight plan is probably correct because, flying those distances, they probably use canned flight plans. Also SIDs (standard instrument departures) and STARs (Standard Terminal Approach Routes) can get you most of the way on some flghts with just one entry in a proposed flight plan.
At one time there was (might still be) a canned approach (STAR) for LaGuardia that started at a VOR in Illinois. Made it easy for the AA and UAL guys who flew it 10 times a month!
Different planes, different ADIRUs:
I agree with the point however my understanding is that it is the same software!
What keeps a fly-by-wire vehicle controlled if there is a sudden disaster in the electrical systems?
gravity, inertia, lift, drag
Doesn’t Southwest fly from Columbus to NYC, Providence RI and Manchester NH?
That would suck. Big time.
If one ADIRU comes from Honeywell and the other comes from Litton (or whoever bought them out) you can pretty much bet the eternal salvation of your soul they don't use the same software.
Much patent-infringement and unfair-restraint-of-trade litigation has transpired over the years between those two companies and their respective RLG products.
Wow. That’s the first time I’ve heard of that one.
WOW! Pucker Factor Infinity on that one!
I wonder what happens to pilotos who "chicken out" and return to base? Can't be good. (Not as bad as what happened, though.)
LaGuardia service starts June 28. To Providence and Manchester, it's four or five hours through Baltimore (then the possible 1-2 hour drive.)
It's business travel. The office prefers US Airways. I don't.
The incident in Post 32 is right up there, too.
The only passengers on a scheduled airline to fly supersonic without being on a Concorde. That's a story of a lifetime.
I think to survive flights like those two linked would be life-changing events.
People have had black hair turn white overnight. (Not all the grown hair, but from the roots.)
For sure. I guarantee there were some cases of post traumatic stress.
Yep asshats flying desks overrule safety 90 % of the time sadly .....
“I wonder what happens to pilotos who “chicken out” and return to base? Can’t be good.”
In 25 years, I did it twice. Nary a word from the head shed. Non-issue. Really! Pilots are seldom, if ever, questioned re. their judgement, unless it’s a stupid, dangerous judgement.
I was only “pressured” once on a safety item. Quit the next day. Plenty of other opportunities, and I continued to improve my career. The guy that did it, never “progressed” above where he was.
I’ll bet a lot of folks wish that the AF pilots had done a 180*, if indeed they did decide to fly into a wall or through a fast-closing sucker hole.
Very, very sad.
June 3, 2009 7:40 p.m. EST
There's also the possibility that a bug in the ADIRU software caused to to wildly overcompensate for the turbulence.
11 p.m. local time The pilot sends a manual signal saying the jet was flying through CBs towering cumulo-nimulus thunderheads.
11:10 p.m. A cascade of automatic messages indicate trouble: The autopilot had disengaged, stabilizing controls were damaged, flight systems deteriorated.
11:13 p.m. Messages report more problems: The system that monitors speed, altitude and direction failed. The main flight computer and wing spoilers failed.
11:14 p.m. The final message indicates a loss of cabin pressure and complete system failure catastrophic events in a plane that was likely already plunging toward the ocean.
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