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Air France A330-200 lost over Atlantic ocean (Page 5)
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glideslope
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May 2, 2011, 02:23 PM
 
Originally Posted by chabig View Post
It's more likely that they flew too close to the sun and the wings melted. The fact that it was night makes it even more intriguing.
No need to Mock. I stated it was IMO. Even Sled Drivers occasionally put it in the ground at night.
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Spheric Harlot
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May 3, 2011, 08:07 AM
 
Originally Posted by glideslope View Post
Both recorders have been recovered. They look in very good shape, and still sealed.
The voice recorder wasn't recovered until last night.

Just saying.
     
glideslope
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May 3, 2011, 05:49 PM
 
Originally Posted by Spheric Harlot View Post
The voice recorder wasn't recovered until last night.

Just saying.
Noted. They were located on the same day.
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Atheist
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May 28, 2011, 03:04 PM
 
Anyone following the latest news reports? Seems quite a few people are ready to blame the crew. I just spent the last hour reading a 53 page thread on another forum. This was one guys summation of the event in layman's terms:

- The pitot tubes were blocked or otherwise rendered ineffective.
- That triggered an unreliable speed event.
- The crew correctly identified the unreliable speed event and the fact that the autopilot and autothrottle had disconnected.
- A pilot took manual control of the plane.
- He should have applied the memory items for unreliable speed: Point the nose 5º above the horizon and set the throttles to climb thrust.
- Instead, he didn't set climb thrust and pointed the nose more than 10º above the horizon.
- The plane climbed, lost speed, and stalled.
- The pilot never recovered from the stall because he didn't apply the correct control inputs, as you know by now, so the plane kept falling stalled for 38,000ft and three minutes.
This of course is based only on what data has been published from the flight data recorder but it seems almost too simple to believe. I'm in no way making any speculations about foul play. Just the opposite actually. I'm quick to accept the simplest explanation as the correct one. Sad if it really was just plain old pilot error.
     
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May 28, 2011, 03:58 PM
 
Looks to me like a total computer failure. All this pitot-failure-causing-the-problem is complete rubbish when you consider there's a GPS showing ground speed - they'd at least have had some idea of speed, altitude and an upcoming stall... ...unless there was a complete blackout.

I've been saying for ages (to those who'll listen) that you've got to be a complete idiot to get on a fly-by-wire plane. Computer goes and you drop like a brick.
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chabig
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May 28, 2011, 04:03 PM
 
Its not likely that seven independent flight control computers with redundant electrical power would suddenly and simultaneously fail. Ground speed is useless. You can't fly with it. Sadly, crew inability to handle pitot static failure is the most likely explanation and one I've long suspected.
     
imitchellg5
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May 28, 2011, 04:09 PM
 
Originally Posted by Doofy View Post
I've been saying for ages (to those who'll listen) that you've got to be a complete idiot to get on a fly-by-wire plane. Computer goes and you drop like a brick.
People used to say the same thing about horseless carriages.

Fly-by-wire can fail just the same as hydraulics can fail, just the same as a car can fail, just the same as you can fall off of a horse.
     
Doofy
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May 28, 2011, 04:16 PM
 
Originally Posted by chabig View Post
Its not likely that seven independent flight control computers with redundant electrical power would suddenly and simultaneously fail. Ground speed is useless. You can't fly with it. Sadly, crew inability to handle pitot static failure is the most likely explanation and one I've long suspected.
I don't know the config of an Airbus, but why didn't the flight envelope protection systems kick in with the overrides on the FADEC and control surfaces? Surely the computers would know the attitude, altitude and power levels if they were still operational and it was just the pitot? Surely the stall warnings would have been going berserk in the cockpit? Wouldn't someone in the cabin have noticed that they were losing alt with their course of action? How does a pilot in command get his licence or type certification if he doesn't know how to handle pitot failure?
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imitchellg5
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May 28, 2011, 04:22 PM
 
Originally Posted by Doofy View Post
I don't know the config of an Airbus, but why didn't the flight envelope protection systems kick in with the overrides on the FADEC and control surfaces? Surely the computers would know the attitude, altitude and power levels if they were still operational and it was just the pitot? Surely the stall warnings would have been going berserk in the cockpit? Wouldn't someone in the cabin have noticed that they were losing alt with their course of action? How does a pilot in command get his licence or type certification if he doesn't know how to handle pitot failure?
The pilot took manual control. He set the plane to climb, but didn't increase power.
     
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May 28, 2011, 04:27 PM
 
4, 8, 15, 16, 23 and 42
     
Atheist
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May 28, 2011, 04:36 PM
 
Originally Posted by Doofy View Post
I don't know the config of an Airbus, but why didn't the flight envelope protection systems kick in with the overrides on the FADEC and control surfaces? Surely the computers would know the attitude, altitude and power levels if they were still operational and it was just the pitot? Surely the stall warnings would have been going berserk in the cockpit? Wouldn't someone in the cabin have noticed that they were losing alt with their course of action? How does a pilot in command get his licence or type certification if he doesn't know how to handle pitot failure?
Because of the failure in the air speed indicator the flight control system reverted to "alternate law" mode. In this mode, the pilot can stall the aircraft.
     
imitchellg5
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May 28, 2011, 04:47 PM
 
Originally Posted by calverson View Post
4, 8, 15, 16, 23 and 42
I hope someone told them Goodwin wasn't on the plane.
     
Doofy
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May 28, 2011, 04:56 PM
 
Originally Posted by Atheist View Post
Because of the failure in the air speed indicator the flight control system reverted to "alternate law" mode. In this mode, the pilot can stall the aircraft.
I'm finding it extremely hard to believe that two fully trained and type-certified pilots don't know how to handle a pitot failure - and don't know they're in a stall from looking at the alti and the attitude.

But, of course, "pilot error" rather than "computer failure" doesn't put Airbus' shares through the floor.
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calverson
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May 28, 2011, 04:58 PM
 
This whole thread reminds me of Oceanic 815, combined with Michael Crichton's Airframe.
     
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May 28, 2011, 05:02 PM
 
Originally Posted by Doofy View Post
Looks to me like a total computer failure. All this pitot-failure-causing-the-problem is complete rubbish when you consider there's a GPS showing ground speed - they'd at least have had some idea of speed, altitude and an upcoming stall... ...unless there was a complete blackout.
When flying through a storm, it's entirely possible that the GPS wouldn't be able to see enough satellite signals to get a fix.
     
Doofy
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May 28, 2011, 05:16 PM
 
Wiki:
The remainder of the messages occurred from 02:11 UTC to 02:14 UTC, containing a fault message for an Air Data Inertial Reference Unit (ADIRU) and the Integrated Standby Instrument System (ISIS).[26][27] At 02:12 UTC, a warning message NAV ADR DISAGREE indicated that there was a disagreement between the independent air data systems (more precisely: that after one of the three independent systems had been diagnosed as faulty and excluded from consideration, the two remaining systems disagreed). At 02:13 UTC, a fault message for the flight management guidance and envelope computer was sent.[28] One of the two final messages transmitted at 02:14 UTC was a warning referring to the air data reference system, the other ADVISORY (Code 213100206) was a "cabin vertical speed warning", indicating that the plane was descending at a high rate.
That's a computer fail, guys.

If you don't think that seven computers on separate PSUs can fail simultaneously, I suggest you contact Facebook and Skype to offer them the solution to their little outages - simply tell them to increase their server count to seven.
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May 28, 2011, 05:26 PM
 
Originally Posted by Doofy View Post
I'm finding it extremely hard to believe that two fully trained and type-certified pilots don't know how to handle a pitot failure - and don't know they're in a stall from looking at the alti and the attitude.

But, of course, "pilot error" rather than "computer failure" doesn't put Airbus' shares through the floor.
Some speculate they ignored the stall warnings believing they were erroneous.

Pilot error is probably more prevalent than we'd like to admit. West Caribbean Air flight 708 crashed in Venezuela on account of the pilots not realizing the plane had gone into a stall. Somewhat similar circumstances.
     
Atheist
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May 28, 2011, 05:30 PM
 
Originally Posted by Doofy View Post
Wiki:


That's a computer fail, guys.

If you don't think that seven computers on separate PSUs can fail simultaneously, I suggest you contact Facebook and Skype to offer them the solution to their little outages - simply tell them to increase their server count to seven.
Everything I've read so far indicates that even with the air speed indicator not functioning, there was nothing preventing the pilot from maintaining control of the aircraft.
     
Doofy
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May 28, 2011, 05:40 PM
 
Originally Posted by Atheist View Post
Pilot error is probably more prevalent than we'd like to admit. West Caribbean Air flight 708 crashed in Venezuela on account of the pilots not realizing the plane had gone into a stall. Somewhat similar circumstances.
Not really. The pilots on that flight realised they had thrust problems and requested descent. That's not a loss of situational awareness.
Easy to blame the extremely well trained dead guys instead of admitting any design faults which may cause the public to want to find their sea legs.

Pilot error = just that flight, it's OK to board others.
Design error = every flight, go by boat.
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freudling
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May 28, 2011, 05:48 PM
 
From what I've seen/read, it looks like Pilot error. Air France has fired back saying the pilots showed professionalism.

However, the Captain was sleeping from what I understand. 3.5 minutes from the start of the situation to crash is insanely little time, so I can see how the Captain wasn't involved right away. They'd have to wake him, and then he'd have to get in there, get briefed, and start analyzing the instruments. Very little time.

But, the two pilots (more inexperienced) 1. Pulled the nose up initially when they should have pointed it down to regain speed and get out of the stall 2. It appears they did not know they were in a stall, until it was too late.

I could be wrong, but it looks like the plane went into a stall 3 times. The initial "error" of pulling the nose up by the inexperienced pilots made the plane drop substantially and looks to be a major cause of the crash. The fact that they went in and out of stalls, and the fact that the report stated that he Pilots had full manual control of the airplane with responsive instruments, shows, to me, the Pilots didn't know what they were doing in the sense that they either didn't believe the instruments in terms of a stall or didn't know how to properly get out of a stall.

The question I have is, what was the Captain doing during the whole situation? Did he come in towards the end?
     
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May 28, 2011, 05:49 PM
 
Originally Posted by Atheist View Post
Everything I've read so far indicates that even with the air speed indicator not functioning, there was nothing preventing the pilot from maintaining control of the aircraft.
That's my point. With the airspeed data gone, there still shouldn't have been a problem. I reckon it was a complete computer failure.

Chabig reckons ground speed is useless, but it's a pretty shit pilot who can't guess (roughly) his airspeed from ground speed and alti. AFAIK, they teach you that kind of thing before they'll give you licence for a Cessna here.
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May 28, 2011, 06:56 PM
 
I think speculation based on the voice recorder transcript is fairly meaningless without the full flight data recorder for context.

We'll hear about it when it's ready.
     
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May 28, 2011, 07:56 PM
 
From what i've been reading, it looks like the crew had no idea they were in a stall, no idea why they were losing altitude.

There is no indication of any widespread systems failure, none of the computer systems reported any errors of any kind, engines and control systems were working until the last seconds. In short, for whatever reason, is is beginning to look like a confused and disorientated crew flew a fully functioning aircraft into the sea.
     
glideslope
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May 28, 2011, 08:08 PM
 
Originally Posted by chabig View Post
Its not likely that seven independent flight control computers with redundant electrical power would suddenly and simultaneously fail. Ground speed is useless. You can't fly with it. Sadly, crew inability to handle pitot static failure is the most likely explanation and one I've long suspected.
Unfortunately, have to agree. Let's hope AF installs the BUSS System on their frames now as LH did, and all 380's have. They could have flown the green line AoA with frozen tubes. Sad day. Godspeed 447.
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glideslope
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May 28, 2011, 08:16 PM
 
Originally Posted by Phileas View Post
From what i've been reading, it looks like the crew had no idea they were in a stall, no idea why they were losing altitude.

There is no indication of any widespread systems failure, none of the computer systems reported any errors of any kind, engines and control systems were working until the last seconds. In short, for whatever reason, is is beginning to look like a confused and disorientated crew flew a fully functioning aircraft into the sea.
I'm sure Spacial Disorientation was rampant on the FD. The Capt should not have been in his rest period going into that WX either.
People are going to see the ugly side of AF's Training over the next year. Too much Bravado.
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Phileas
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May 28, 2011, 08:21 PM
 
As a pilot, what do you do when you're not sure which of your instruments are working correctly and which ones don't?
     
glideslope
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May 28, 2011, 10:33 PM
 
Originally Posted by Phileas View Post
As a pilot, what do you do when you're not sure which of your instruments are working correctly and which ones don't?
90% N1 and 2.5 up pitch, wings level until you figure it out. At least on a 332, IMO.
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Phileas
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May 28, 2011, 11:06 PM
 
Isn't that pretty much what the crew did?
     
imitchellg5
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May 28, 2011, 11:46 PM
 
No, they didn't add thrust. As myself, and others, have said again. And it was 10 up.
     
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May 29, 2011, 04:39 AM
 
Originally Posted by Phileas View Post
From what i've been reading, it looks like the crew had no idea they were in a stall
What the hell have you been reading?

Originally Posted by imitchellg5 View Post
No, they didn't add thrust.
Yes they did - they went TO/GA.

Originally Posted by imitchellg5 View Post
And it was 10 up.
Where does it say that?
http://www.bea.aero/fr/enquetes/vol....mai2011.en.pdf
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May 29, 2011, 06:40 AM
 
Originally Posted by Phileas View Post
Isn't that pretty much what the crew did?


Between 2 h 10 min 16 and 2 h 10 min 50 the control inputs resulted in a climb at 7,000 ft per minute, during that same period of time it would appear that the speed information on the PFD became valid again.

At 2 h 10 min 51 the stall warning sounded, with the angle of attack of 6 degrees. It would appear to be a false stall warning. Application of TOGA at that angle of attack at that altitude does little until the engine spools up to TOGA, that could take anything up to 30 seconds.

However nose up pitch inputs were made, as the aircraft was not stalled, it resulted in a TOGA climb. The ISIS speed indications then returned to normal at around 2 h 11 min 05. The change to the THS angle is a result of the pitch up nose inputs, and the angle of attack was increased by 10 degrees. This is indicating a dynamic "zoom" style climb (like a GPWS recovery) resulting in a high altitude unusual attitude entry.

To recovery from such a situation is not easy, you are rapidly running out of time as the kinetic energy is reducing rapidly. The correct recovery technique would have been
Recognize and confirm the situation
Apply as much as full nose-down elevator
Apply appropriate nose-down stabilizer trim
Reduce thrust
Roll (adjust bank angle) to obtain a nose-down pitch rate, and hold that bank angle
When approaching the horizon, roll to wings level
Check airspeed and adjust thrust to 90% N1
Establish the correct pitch attitude in this case 2.5 degrees

As we see at 2 h 12 min 02 elements if this recovery were done, and the aircrafts angle of attack decreased and the airspeed became valid again, they would have been around FL300-FL250 at that time. Further nose down pitch rate was required to fully recover, however the stall warning sounding again may have changed the pilots "programming" from the unusual attitude recovery (keep the angle of bank until the nose is on the horizon) to the approach to the stall recovery (roll wings level) which would have reduced the nose down pitch rate, however there is no indication of that application of TOGA again.

The frame hit the water at 125 mph ground speed. Spacial Disorientation, and poor training, IMO.
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May 29, 2011, 06:47 AM
 
Originally Posted by Doofy View Post
Chabig reckons ground speed is useless, but it's a pretty shit pilot who can't guess (roughly) his airspeed from ground speed and alti. AFAIK, they teach you that kind of thing before they'll give you licence for a Cessna here.
At cruising altitude, groundspeed is worthless because of winds aloft, and the difference between indicated and true airspeed. Not only that, but an Airbus cockpit doesn't display GPS position or speed. GPS is just one input to the avionics suite, which integrates sensors to display a consolidated nav solution.

To clarify what I said about GPS, below a couple of thousand feet it might help, but not up high where the wind is strong and the difference between indicated and true airspeed is great.
     
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May 29, 2011, 07:41 AM
 
Originally Posted by chabig View Post
At cruising altitude, groundspeed is worthless because of winds aloft, and the difference between indicated and true airspeed. Not only that, but an Airbus cockpit doesn't display GPS position or speed. GPS is just one input to the avionics suite, which integrates sensors to display a consolidated nav solution.

To clarify what I said about GPS, below a couple of thousand feet it might help, but not up high where the wind is strong and the difference between indicated and true airspeed is great.
Obviously, I'm a "below 10,000" man. But is the wind speed up there so great that a guess at speed couldn't keep you between Vs and Vne?

If the Airbus doesn't display GPS position or speed... ...well, that's another matter. What the hell is the other glass displaying? Facebook? Wouldn't you have a rough clue about how fast you're going by how quickly the next waypoint is arriving?
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May 29, 2011, 08:55 AM
 
Originally Posted by Doofy View Post
that a guess at speed couldn't keep you between Vs and Vne?
Remind me never to get on a plane with you - at least not a commercial plane

I talked to a friend of mine, who flies long haul for Air Canada, about this yesterday. Her remarks about Air France pilots were less than flattering*. She was of the opinion that there's a culture of devil-may-care within Air France and that caution is being perceived as weakness, resulting in the crew not avoiding the weather that night over the South Atlantic.

I don't know if you remember this, but in 2005 an Air France crew forced a plane down halfway a rain slicked runway here in Toronto, overshooting it and breaking up the plane as it slid into a ravine. It was an absolute miracle that all passengers survived. Reason I bring this us is because she cited this as another example of Air France culture.

* One person's personal opinion - I am aware that this doesn't make it absolute truth.
     
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May 29, 2011, 09:24 AM
 
Originally Posted by Phileas View Post
Remind me never to get on a plane with you - at least not a commercial plane


Originally Posted by Phileas View Post
I talked to a friend of mine, who flies long haul for Air Canada, about this yesterday. Her remarks about Air France pilots were less than flattering*. She was of the opinion that there's a culture of devil-may-care within Air France and that caution is being perceived as weakness, resulting in the crew not avoiding the weather that night over the South Atlantic.
The planes travelling the same route that night weren't affected by the weather... ...because, apparently (according to a couple of sources I looked at yesterday), there wasn't much weather except in the minds of the media.

Originally Posted by Phileas View Post
I don't know if you remember this, but in 2005 an Air France crew forced a plane down halfway a rain slicked runway here in Toronto, overshooting it and breaking up the plane as it slid into a ravine. It was an absolute miracle that all passengers survived. Reason I bring this us is because she cited this as another example of Air France culture.
Thing is, all of the Air France pilots will need to have been trained to full Euro standards before they got their licence, and will need to have been type certified. AFAIK, the requirements for gaining one's licence in Europe far exceed those of North America (there's moves to disallow US-trained private pilots from using Euro airspace). So I'm not convinced*.

(* I may be wrong, of course.)
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May 29, 2011, 11:35 AM
 
Originally Posted by Doofy View Post
Obviously, I'm a "below 10,000" man. But is the wind speed up there so great that a guess at speed couldn't keep you between Vs and Vne?
Things are different in high performance airplanes. Here's a test for you. You're at 35,000 ft. You're GPS shows a ground speed of 410 knots. What's your indicated airspeed? See the problem? By the way, Vs and Vne (Vmo/Mmo actually) are within 20 knots of each other. Not so easy, is it?

Originally Posted by Doofy View Post
If the Airbus doesn't display GPS position or speed... ...well, that's another matter. What the hell is the other glass displaying? Facebook? Wouldn't you have a rough clue about how fast you're going by how quickly the next waypoint is arriving?
When safety of flight depends upon you knowing how fast your flying, you can't hack the clock and see how many miles you cover in a minute. The best thing they could have done would have been to hold attitude and thrust constant and follow the procedure for unreliable airspeed. In their defense, I am not aware of any companies that train total pitot-status failure in great depth. There is a procedure and it should be followed.
     
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May 29, 2011, 11:43 AM
 
Nothing in the reported messages indicates any computer failures. It looks to me like they were all working while receiving erroneous and contradictory pitot-static data.
     
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May 29, 2011, 01:01 PM
 
Nm, posted a dead link.
( Last edited by Phileas; May 29, 2011 at 01:29 PM. )
     
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May 29, 2011, 01:31 PM
 
Originally Posted by chabig View Post
Things are different in high performance airplanes. Here's a test for you. You're at 35,000 ft. You're GPS shows a ground speed of 410 knots. What's your indicated airspeed? See the problem? By the way, Vs and Vne (Vmo/Mmo actually) are within 20 knots of each other. Not so easy, is it?
Your stall speed is within 20 knots of your never exceed speed? What kind of idiot designs a plane like that?

The answer is: I don't know. I don't have an E6B (etc.), operating manual and a weather report. But since the maximum speed of an A300 is 470 kts and the minimum speed is somewhere around 250 kts, it'd perhaps be prudent to head for 360 kts - thus having a 100 kt margin either way to account for wind and still be within "not falling out of the sky immediately" parameters. ?
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May 29, 2011, 01:36 PM
 
Originally Posted by Doofy View Post
Your stall speed is within 20 knots of your never exceed speed? What kind of idiot designs a plane like that?
doofy, no time right now for a full answer, but that's normal for all airplanes. See http://en.wikipedia.org/wiki/Coffin_corner_(aviation)
     
Doofy
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May 29, 2011, 01:40 PM
 
Ta. I'll go have a read of that.
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That's where there's thunder... and the wind shouts back.
     
Phileas
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May 29, 2011, 03:10 PM
 
Here is another explanation of coffin corner: Cockpit Conversation: Coffin Corner

In really extreme circumstances, one wing can, theoretically, be in Vs, while the other is in Vne.
     
ghporter
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May 29, 2011, 05:39 PM
 
I like the Cockpit Conversation explanation for its completeness, but that graph in Wikipedia makes it very clear at a glance. The issue is at very high altitudes (with very thin air) and at very high speeds, the whole lift equation gets pretty dicey. The graph in the Wiki article uses 60,000 feet as a max ceiling, which helps reinforce the "high altitude" issue.

Does the Airbus 330 depend only on pitot/static data for airspeed? Wouldn't it also be smart to have a GPS input, and maybe even a RAT-like input? I'm not a pilot, but I've worked on and around aircraft a lot; multiple, independent and redundant sensor systems are the norm in anything bigger than a 4-seat, single engine private plane, so what's the design of the A330 in this area?

I'm also glad my last flights on Airbus aircraft (A319s) were before I read this stuff... As Doofy points out, this isn't good for the aircraft manufacturer's image, whether it was actually pilot error or a computer problem

Glenn -----OTR/L, MOT, Tx
     
chabig
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May 29, 2011, 05:51 PM
 
It's industry standard to use air data sensors for air data (seems obvious, doesn't it?) To my knowledge, the only machine that uses other means is the space shuttle because air data probes would burn off during reentry. There is still redundancy in the system--typically three independent air data systems.

Boeing jets are no different, so don't cast blame on Airbus.
     
chabig
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May 29, 2011, 05:54 PM
 
ghporter, is this the graph you liked? It's a very good idealization of what's going on.

Datei:CoffinCorner.png – Wikipedia
     
ghporter
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May 29, 2011, 06:15 PM
 
I guess I put way too much thought into asking a vague question: what is the A330's air data sensor design? Where are the tubes located, and is it possible for more than one sensor to be fouled by the same phenomenon at the same time?

The use of pitot/static sensors has a long history of reliability. But if you have multiple, redundant flight data computers processing inputs from the same three sensors, it should be trivial to identify when one sensor is unreliable, right? Apparently that did not happen effectively in the incident in question. Adding "reference" sensors such as GPS might be a good idea as an improvement to the current system. A ram air turbine in a duct could be useful at lower speeds as well. I was pretty much just mussing about "how to do it better."

Also, I didn't mean to poke at Airbus, but with the current discussion being about Airbus, I merely pointed out that I have recently flown on A319s...as well as Canadair RJ900s, which have not been in the press to my knowledge for accidents. It doesn't give anyone a warm fuzzy to know that this sort of thing can happen on an advanced commercial aircraft, and whether the airspeed systems are the same on Boeing and Airbus aircraft or not, Airbus is taking the heat right now.

Glenn -----OTR/L, MOT, Tx
     
chabig
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May 29, 2011, 06:37 PM
 
Air data is important so a lot of thought and redundancy goes into the design of the air data system.

The system consists of three identical and independent ADIRU (Air Data and Inertial Reference Units). Each ADIRU has two parts, each can work separately from the other in case of failure. We are concerned right now with the ADR (Air Data Reference) which supplies barometric altitude, airspeed, mach, angle of attach, temperature, and overspeed warnings.

There are multiple external air data sensors that feed data to this system: 3 pitot probes, 6 static pressure ports, 3 angle of attack sensors, and 2 total temperature probes. The sensors are electrically heated to prevent them from icing up. Eight air data modules convert pneumatic data from the pitot and static probes into digital numeric data for the ADIRUs.

The probes are located separately and away from each other to prevent one mishap from taking them all out. Two pitot probes are on the left forward fuselage, one is on the right. Two AOA probes are on the left forward fuselage, one is on the right. One TAT probe is on each side. Three static ports are on each side of the forward fuselage.

Solid engineering goes into the design of these systems. Reference sensors, GPS, turbines(?) are all layman's ideas, with no solid engineering to back them up.

As for warm fuzzies about bad things happening on commercial aircraft, I remind you of the industry's unsurpassed safety record. When you step foot onto an airplane, you are safer than you were in the car on the way to the airport.
     
Phileas
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May 29, 2011, 07:15 PM
 
The numbers are:

Odds of being killed on a single trip :
Airliner - 52.6 million to 1
Automobile - 7.6 million to 1
Commuter Airline - 581,395 to 1
Commuter Plane Air taxi on demand - 163,934 to 1
General Aviation - 73,187 to 1
     
Doofy
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May 29, 2011, 07:22 PM
 
Been inclined to wander... off the beaten track.
That's where there's thunder... and the wind shouts back.
     
glideslope
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May 29, 2011, 08:19 PM
 
Originally Posted by chabig View Post
Air data is important so a lot of thought and redundancy goes into the design of the air data system.

The system consists of three identical and independent ADIRU (Air Data and Inertial Reference Units). Each ADIRU has two parts, each can work separately from the other in case of failure. We are concerned right now with the ADR (Air Data Reference) which supplies barometric altitude, airspeed, mach, angle of attach, temperature, and overspeed warnings.

There are multiple external air data sensors that feed data to this system: 3 pitot probes, 6 static pressure ports, 3 angle of attack sensors, and 2 total temperature probes. The sensors are electrically heated to prevent them from icing up. Eight air data modules convert pneumatic data from the pitot and static probes into digital numeric data for the ADIRUs.

The probes are located separately and away from each other to prevent one mishap from taking them all out. Two pitot probes are on the left forward fuselage, one is on the right. Two AOA probes are on the left forward fuselage, one is on the right. One TAT probe is on each side. Three static ports are on each side of the forward fuselage.

Solid engineering goes into the design of these systems. Reference sensors, GPS, turbines(?) are all layman's ideas, with no solid engineering to back them up.

As for warm fuzzies about bad things happening on commercial aircraft, I remind you of the industry's unsurpassed safety record. When you step foot onto an airplane, you are safer than you were in the car on the way to the airport.
Yet no information from the (R) Pitot Probe is captured on the FDR in this design. Could have been helpful.
Just sayin....
To know your Enemy, you must become your Enemy.”
Sun Tzu
     
 
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