AF447 wreckage found
Joined: Sep 2008
Posts: 28
Likes: 0
From: LPPR
@wallybird 7
They were not aware until after TO.
Aeroperu 603 Transcripcion Del Voice Recorder (Espanol)
The taped static port occurred on the Peruvian 757. Unsure if they were aware of it during take-off.
Aeroperu 603 Transcripcion Del Voice Recorder (Espanol)
Joined: Nov 1999
Posts: 176
Likes: 0
From: EIDW
I will begin with the A310-325 approaching CDG years ago.
Capturing G/P from above the plane overspeeded the flaps placard, obviously, THE SMART COMPUTER decided it is a go-around so throttles up, and nose-up trim!
The dummy in the L/H site pressed the yoke, and pressed the yoke and...
---> THE SMART COMPUTER trimmed further nose up, and trimmed...
Capturing G/P from above the plane overspeeded the flaps placard, obviously, THE SMART COMPUTER decided it is a go-around so throttles up, and nose-up trim!
The dummy in the L/H site pressed the yoke, and pressed the yoke and...
---> THE SMART COMPUTER trimmed further nose up, and trimmed...
Don't blame Airbus computers for everything. They do not decide to go around, and they do not simply trim full nose up 'cause they feel like it.
Joined: Jan 2001
Posts: 739
Likes: 0
From: Dallas, TX USA
Pitch Trim
One item that continues to puzzle me the most about this accident is what trimmed the Horizontal Stabilizer from +3 to +13 in one minute. Who did that, or what system did that? It was a lethal move.
Joined: May 2011
Posts: 61
Likes: 0
From: venice, ca
Stall confusion
Let me add to the confusion. No one seems to have an answer as to why the plane zoomed up to 38,000 feet. At that time also the report mentions that the auto-pilot also kicked off. Thus the plane was in Alternate Law which to me means the only control of the plane was pitch thru the electric trim, and roll via the side stick which controls the rudder.
Once the plane was in a deep stall at low speed I don't know if the plane would respond to any flight controls. (I also don't know what the stall characteristics of the plane are)
If any of that is the case, then the pilots were simply along for the ride.
Once the plane was in a deep stall at low speed I don't know if the plane would respond to any flight controls. (I also don't know what the stall characteristics of the plane are)
If any of that is the case, then the pilots were simply along for the ride.
Joined: Jan 2006
Posts: 454
Likes: 3
From: Georgia, USA
Let me add to the confusion. No one seems to have an answer as to why the plane zoomed up to 38,000 feet. At that time also the report mentions that the auto-pilot also kicked off. Thus the plane was in Alternate Law which to me means the only control of the plane was pitch thru the electric trim, and roll via the side stick which controls the rudder.
Again I ask the question, is this site incorrect when it states that auto trim is still used for over speed protection in Alternate Law!
http://www.airbusdriver.net/airbus_fltlaws.htm
Joined: Jul 2008
Posts: 264
Likes: 0
From: Bali, Indonesia
Metal Tubes?
Interesting discussion. Central to all of this was the failure of the Pitots, it seems. Excuse my ignorance but in the 21st century, why do we still have to rely on hollow metal tubes to feed critical systems? Isn't it possible to feed such information as air speed from GPS or other more sophisticted satellite systems?
Joined: Apr 2002
Posts: 3,349
Likes: 1
From: FUBAR
BarbiesBoyfriend,
Ken, I hear what you are saying, but. . . . do you think it was that they couldn't fly their aircraft, or that Airbus made it inordinately difficult (if not indeed impossible )to do in their situation.
I am still not too sure if all of this should be heaped on the crew. Don't think the machine was blameless, or too helpful, here.
Ken, I hear what you are saying, but. . . . do you think it was that they couldn't fly their aircraft, or that Airbus made it inordinately difficult (if not indeed impossible )to do in their situation.
I am still not too sure if all of this should be heaped on the crew. Don't think the machine was blameless, or too helpful, here.
Joined: Nov 2003
Posts: 952
Likes: 0
From: Melbourne
philipat
Short answer: No!
21st Century has got nothing to do with it. GPS will give you groundspeed only, and GPS isn't 100% reliable as you can't always get enough satellites to give you accurate information.
In any case, GPS wont give you the direction and speed of the air that you're moving in.
Pitot tubes are still the best way to get accurate airspeed information.
Short answer: No!
21st Century has got nothing to do with it. GPS will give you groundspeed only, and GPS isn't 100% reliable as you can't always get enough satellites to give you accurate information.
In any case, GPS wont give you the direction and speed of the air that you're moving in.
Pitot tubes are still the best way to get accurate airspeed information.
Joined: Jun 2009
Aviation Qualifications: Military
Posts: 1,851
Likes: 645
From: florida
Deep stalls? yes, they exist
I wish to correct a misconception or two concerning the so-called "deep stall"
As Newt told Ripley, " my parents told me there weren't any REAL monsters.... but there are."
So I pulled stuff from a pre-historic publication and posted on the technical thread concerning AF447. PLZ read this and think about it, especially the quote from a "golden arm" test pilot describing what it felt like.
http://www.pprune.org/tech-log/44963...ml#post6432295
Second, many folks associate a "deep stall" with T-tail designs and airflow over the horizontal stab/elevators. As you can see from the Viper, this is not a requirement. The problem occurs with a combination of c.g. and AoA and low speed. I flew the VooDoo as a yute, and it had the T-tail and it had a problem as someone alluded to here. At a sufficient AoA, downwash over that T-tail caused ever-increasing nose up pitch - we called it 'pitch up". It could happen at all speeds. but we didn't enter a "deep stall", we flipped end over end and rolled and yawed. Quite a ride. Due to conventional static stability and c.g. it was possible to regain control even without using the drag chute. however, SOP was wait until IAS was below drag chute limits and deploy the sucker!! Saved thousands of feet, and you didn't have to be a clone of Chuck Yeager.
Lastly, FBW is a lot more than a simple command of the control surfaces via electrical signals from the flight controls and the hydraulics that are there to move the suckers. True, the Concorde was closer to that, but I'll guarantee that there were some filters and dynamic pressures used to limit deflection and the rate of deflection. Not to the extent of the Viper or the late Airbus designs, though.
I can see a case to be made that the AF jet climbed steeply, ran out of air molecules over the elevator/THS and stalled. With the THS at a full ( within a degree) nose up command, and with a c.g. aft of most jets, it could enter a "deep stall" just as we had in the Viper.
As Newt told Ripley, " my parents told me there weren't any REAL monsters.... but there are."
So I pulled stuff from a pre-historic publication and posted on the technical thread concerning AF447. PLZ read this and think about it, especially the quote from a "golden arm" test pilot describing what it felt like.
http://www.pprune.org/tech-log/44963...ml#post6432295
Second, many folks associate a "deep stall" with T-tail designs and airflow over the horizontal stab/elevators. As you can see from the Viper, this is not a requirement. The problem occurs with a combination of c.g. and AoA and low speed. I flew the VooDoo as a yute, and it had the T-tail and it had a problem as someone alluded to here. At a sufficient AoA, downwash over that T-tail caused ever-increasing nose up pitch - we called it 'pitch up". It could happen at all speeds. but we didn't enter a "deep stall", we flipped end over end and rolled and yawed. Quite a ride. Due to conventional static stability and c.g. it was possible to regain control even without using the drag chute. however, SOP was wait until IAS was below drag chute limits and deploy the sucker!! Saved thousands of feet, and you didn't have to be a clone of Chuck Yeager.
Lastly, FBW is a lot more than a simple command of the control surfaces via electrical signals from the flight controls and the hydraulics that are there to move the suckers. True, the Concorde was closer to that, but I'll guarantee that there were some filters and dynamic pressures used to limit deflection and the rate of deflection. Not to the extent of the Viper or the late Airbus designs, though.
I can see a case to be made that the AF jet climbed steeply, ran out of air molecules over the elevator/THS and stalled. With the THS at a full ( within a degree) nose up command, and with a c.g. aft of most jets, it could enter a "deep stall" just as we had in the Viper.
Joined: Mar 2000
Posts: 147
Likes: 0
From: canada
Simulator time.
Exnomad, in the 11 years that I flew the A320, never once did we practice in the simulator :
A. Dual engine failure
B. Airspeed failure
C. Landing using only the standby instruments
D. Ditching
The pilots are expected to fly these automated airplanes for 6 months, then perform perfectly in the sim with very little practice.
Airlines have been cutting down on sim time due to cost at a time when automated aircraft are far more complex.
I believe that one day (4 hours) of training in the sim then doing a check ride the next day is NOT enough to cover all the training required. I have always felt that simulators should be used for training, not checking. The government inspectors can sit in on the training to make sure it is proper but the check ride should be done in the aircraft on a normal pax flight with a normal crew. That way more time would be available for crew training since money is tight.
In the case of AF447, the crew should have avoided the ITCZ weather in the first place, therefore all the recovery techniques would have been unnecessary. It's much easier to avoid a problem than it is to correct it.
A. Dual engine failure
B. Airspeed failure
C. Landing using only the standby instruments
D. Ditching
The pilots are expected to fly these automated airplanes for 6 months, then perform perfectly in the sim with very little practice.
Airlines have been cutting down on sim time due to cost at a time when automated aircraft are far more complex.
I believe that one day (4 hours) of training in the sim then doing a check ride the next day is NOT enough to cover all the training required. I have always felt that simulators should be used for training, not checking. The government inspectors can sit in on the training to make sure it is proper but the check ride should be done in the aircraft on a normal pax flight with a normal crew. That way more time would be available for crew training since money is tight.
In the case of AF447, the crew should have avoided the ITCZ weather in the first place, therefore all the recovery techniques would have been unnecessary. It's much easier to avoid a problem than it is to correct it.
Joined: Mar 2000
Posts: 147
Likes: 0
From: canada
GPS
Di Vosh, during the last 2 years of my flying career I carried a hand held portable GPS unit with me on all my flights, just in case. This was in response to the 757 crash out of the Puerto Plata DR one night due to loss of airspeed indication. Also the the crash out of Lima Peru with taped over static ports.
The GPS provided me with ground speed, course and true altitude (not pressure alt). That is all the pilot of a jet needs to stay alive when all hell breaks loose.
My advice to all pilots is, get and carry a hand held GPS unit and take it with you on all your flights. And use it, just in case. Also please do not fly into CB's, they can give you a headache.
The GPS provided me with ground speed, course and true altitude (not pressure alt). That is all the pilot of a jet needs to stay alive when all hell breaks loose.
My advice to all pilots is, get and carry a hand held GPS unit and take it with you on all your flights. And use it, just in case. Also please do not fly into CB's, they can give you a headache.
Joined: Mar 2000
Posts: 147
Likes: 0
From: canada
Distress call
fboizard, I'll try to answer you. First of all, what good would it have done. No one on the ground could have helped them.
Second, They were just too busy hand flying and dealing with a multitude of warnings.
Second, They were just too busy hand flying and dealing with a multitude of warnings.
Joined: Nov 2003
Posts: 952
Likes: 0
From: Melbourne
Thermostat
Point taken re: hand held GPS. But I'm assuming (foolish to assume?) that the A330 has an on-board GPS and would display groundspeed on the EHSI.
I fly a Dash8-300 (not new technology) and we have this feature.
DIVOSH!
Point taken re: hand held GPS. But I'm assuming (foolish to assume?) that the A330 has an on-board GPS and would display groundspeed on the EHSI.
I fly a Dash8-300 (not new technology) and we have this feature.
DIVOSH!
Joined: Jun 2009
Posts: 14
Likes: 0
From: USA
From Fallows Atlantic Mag
Reading the BEA report, there's no indication that the crew lost all instruments, simply all instruments dependent on the pitot-static system. Attitude, derived from a combination of rate and attitude gyros should still have been reliable. The key difficulty faced by the crew was that the standard practice of using pitch + power to maintain safe flight without air data didn't seem to be working and the problem is that it won't if the aircraft is already stalled. With the airbus' FBW [fly by wire] system and passive stick, the crew would have none of the force or buffet cues through the side-stick that might have told them this.
At the same time, if the attitude of the aircraft is nominal [normal], power is nominal, but vertical speed is indicating -10,000ft per minute, the most likely cause is that the airplane is stalled. Yes, the VS indications could have been bad also, but it's less likely to be wrong than airspeed (requires only static pressure) and the crew had already tried the standard response.<<
At the same time, if the attitude of the aircraft is nominal [normal], power is nominal, but vertical speed is indicating -10,000ft per minute, the most likely cause is that the airplane is stalled. Yes, the VS indications could have been bad also, but it's less likely to be wrong than airspeed (requires only static pressure) and the crew had already tried the standard response.<<