AF447 wreckage found
Join Date: Jul 2000
Location: Nirvana..HAHA..just kidding but,if you can tell me where it is!
Posts: 350
Received 0 Likes
on
0 Posts
Regarding other traffic on the Atlantic that night, I wonder how much useful weather info was being passed on 123.45, by the earlier flights, in order to help fellow crews, on the same route as AF447. Many years of Atlantic crossings taught me that AF and LH seem to be the two airlines hesitant at giving, or receiving such info,or at least, they never replied!!!
We need to look after each other in this industry with all the pitfalls!...Monitoring Data and 121.5 does use up spare radios however!
We need to look after each other in this industry with all the pitfalls!...Monitoring Data and 121.5 does use up spare radios however!
Join Date: May 2010
Location: Germany
Posts: 73
Likes: 0
Received 0 Likes
on
0 Posts
AutoTrim?
Hi there,
german news outlet "Der Spiegel" has an interesting story about a german aerospace engineer (Professor, that is...) who experienced some strange (disturbing) behaviour in the simulator. Read yourself (english version):
Air France*Catastrophe: Victims' Families Propose Grounding All*A330s - SPIEGEL ONLINE - News - International
german news outlet "Der Spiegel" has an interesting story about a german aerospace engineer (Professor, that is...) who experienced some strange (disturbing) behaviour in the simulator. Read yourself (english version):
Air France*Catastrophe: Victims' Families Propose Grounding All*A330s - SPIEGEL ONLINE - News - International
Join Date: Oct 2003
Location: Hampshire, UK
Posts: 207
Likes: 0
Received 0 Likes
on
0 Posts
According to flight global, automatic stab trim should have been inhibited when alpha > 30 degrees - Stalled AF447 did not switch to abnormal attitude law but it was not.
So is this saying that the flight control system continued to do what was asked of it - trim for attitude / 1g and therefore trimmed in the stall - when it should have dropped out?
Edit: Isn't 30 degrees AOA..rather high?
So is this saying that the flight control system continued to do what was asked of it - trim for attitude / 1g and therefore trimmed in the stall - when it should have dropped out?
Edit: Isn't 30 degrees AOA..rather high?
Join Date: Sep 2004
Location: SLF, living somewhere East in the West
Posts: 235
Likes: 0
Received 0 Likes
on
0 Posts
As per the SPIEGEL article the relatives are basically demanding from a french judge to ground all A 330 and 340 worldwide until software issues regarding the trim of the elevator are resolved and to prevent further accidents.
As a SLF I find that somewhat mind boggling. I never had issues flying with the Airbusses but I am getting a bit more skeptical... I would like to know if any of the major carriers (BA, AF, LH, KLM, USAir, UA Delta) are analyzing the issue at hand...?
As a SLF I find that somewhat mind boggling. I never had issues flying with the Airbusses but I am getting a bit more skeptical... I would like to know if any of the major carriers (BA, AF, LH, KLM, USAir, UA Delta) are analyzing the issue at hand...?
Join Date: May 2009
Location: UK
Age: 41
Posts: 39
Likes: 0
Received 0 Likes
on
0 Posts
AoA at less than 60knots
Guys maybe a stupid question:
How does the computer know that airspeed is less than 60knots so as to sound off the stall alarm if the airspeed is unreliable?
What if the plane is stalled at 80knots airspeed and the airspeed is unreliable 'showing' 50 knots. Will the stall alarm sound off?
AoA sensor is a small flap exposed in the airstream, how does the output of it in the cockpit (stall sound) is conected to an airspeed instrument that can be unreliable?
Can anybody expalin why AoA is not available under 60knots? If for some reason speed (reliable or not) is less than 60knots then there is no AoA input for the computers?
I'm obviously not a pilot, but I haven't understood the AoA unavailability under 60knots.
How does the computer know that airspeed is less than 60knots so as to sound off the stall alarm if the airspeed is unreliable?
What if the plane is stalled at 80knots airspeed and the airspeed is unreliable 'showing' 50 knots. Will the stall alarm sound off?
AoA sensor is a small flap exposed in the airstream, how does the output of it in the cockpit (stall sound) is conected to an airspeed instrument that can be unreliable?
Can anybody expalin why AoA is not available under 60knots? If for some reason speed (reliable or not) is less than 60knots then there is no AoA input for the computers?
I'm obviously not a pilot, but I haven't understood the AoA unavailability under 60knots.
Join Date: Aug 2009
Location: Germany
Age: 67
Posts: 1,777
Likes: 0
Received 0 Likes
on
0 Posts
Hi,
Cause Airbus decided it will not be available cause their planes never go (in air) at this slow speed ............
Can anybody expalin why AoA is not available under 60knots?
Join Date: Oct 2006
Location: Gone Flying...
Age: 63
Posts: 270
Likes: 0
Received 0 Likes
on
0 Posts
I loved your post, "The Shadow". I agree with you.
As I have wrote a number of pages back, there are a number of questions waiting to be answered:
Why did BEA apparently decided to disclose, only a part of the information?
As I have wrote a number of pages back, there are a number of questions waiting to be answered:
- What kind of information was being "shown" on Pilot Flying's #2 PFD/ND (yes I know it is not registered but, are there any conversation clues(?), other than the ones selected by the BEA to be transcripted to the report). Was he first responding to an overspeed indication,(2h10m16s) and only after he has reached 37500ft, (2h10m51s) he has triggered TO/GA in response to another "Stall, Stall" warning?
- What was the role played by the 13º Trimmable Horizontal Stabilizer (THS) plus the 4.9Ton of fuel stuck on the Trim Tank?
- What was the role of the "systems invalidations" design that below 60kts and 30kts, cancelled the "Stall, Stall" Automatic Call-Out Warning, and may have lead the pilots think they were out of it during precious seconds?
- We know that the Captain was able to reach the cockpit. It seems that by that time the speed read-outs were so low that the Stall Warning was out...but, what was his assumption of what was going on? By then, the aircraft was at about 35000ft, Pitch at about 15º and thrust 100%. Did he tell anything? Did he try to help? Didn't he notice the high pitch? Didn't he notice, the wings bouncing and the PF saying (only a minute after his entrance in the cockpit), that they were reaching FL100?
- Was the PNF so occupied, handling the ECAM, that he didn't notice the vertical speed rate, until FL100 was called off?
- What was the role played by the 13º Trimmable Horizontal Stabilizer (THS) plus the 4.9Ton of fuel stuck on the Trim Tank?
- What was the role of the "systems invalidations" design that below 60kts and 30kts, cancelled the "Stall, Stall" Automatic Call-Out Warning, and may have lead the pilots think they were out of it during precious seconds?
- We know that the Captain was able to reach the cockpit. It seems that by that time the speed read-outs were so low that the Stall Warning was out...but, what was his assumption of what was going on? By then, the aircraft was at about 35000ft, Pitch at about 15º and thrust 100%. Did he tell anything? Did he try to help? Didn't he notice the high pitch? Didn't he notice, the wings bouncing and the PF saying (only a minute after his entrance in the cockpit), that they were reaching FL100?
- Was the PNF so occupied, handling the ECAM, that he didn't notice the vertical speed rate, until FL100 was called off?
Join Date: Nov 2006
Location: SoCalif
Posts: 896
Likes: 0
Received 0 Likes
on
0 Posts
Barnyard Logic
Go outside, farmer, and look at the weather vane on your barn. Note, it aligns into the wind because its tail has more area than its point, which is only needed for static nose/tail balance. Note that it also has a lightning rod above it.
Angle of Attack is vertical measure of relative wind. The AOA sensor is just a high priced vertical weathervane, as seen previously on this thread. It's high priced because it has to be reliable in all imaginable weather and flight conditions, including direct lightning strikes or sweeps. It has some inertia and frictional damping to prevent flutter in all possible conditions.
Therefore, just as your barn's weathervane can be erroneious below about 10 knots wind, the AOA sensor cannot be trusted below about 60 knots.
You got a better AOA sensor? If not, why are you criticizing lack of Stall Warning below 60 knots?
If you don't understand this, maybe your time would be better spent shoveling out the barn.
Angle of Attack is vertical measure of relative wind. The AOA sensor is just a high priced vertical weathervane, as seen previously on this thread. It's high priced because it has to be reliable in all imaginable weather and flight conditions, including direct lightning strikes or sweeps. It has some inertia and frictional damping to prevent flutter in all possible conditions.
Therefore, just as your barn's weathervane can be erroneious below about 10 knots wind, the AOA sensor cannot be trusted below about 60 knots.
You got a better AOA sensor? If not, why are you criticizing lack of Stall Warning below 60 knots?
If you don't understand this, maybe your time would be better spent shoveling out the barn.
Join Date: Jan 2008
Location: Berkeley
Posts: 67
Likes: 0
Received 0 Likes
on
0 Posts
"a precise speed is critical. Just 15 kilometers per hour (9.3 mph) faster or slower and the plane can stall...." Doomed Flight AF 447: Questions Raised about Airbus Automated Control System - SPIEGEL ONLINE - News - International Question -- at the top of a big storm cell, in that kind of turbulence, isn't the air around the aircraft changing direction faster than plus or minus 15 kph rapidly? what is the aircraft/pilot/computer detecting?
Join Date: Aug 2009
Location: Germany
Age: 67
Posts: 1,777
Likes: 0
Received 0 Likes
on
0 Posts
Hi,
In Bussiness Week ....
Air France Crew May Have Faced Baffling Data in 2009 Crash - Businessweek
In Bussiness Week ....
Air France Crew May Have Faced Baffling Data in 2009 Crash - Businessweek
"The data and cockpit voice recording suggest the pilots never realized that the plane had stalled, BEA Chief Investigator Alain Bouillard said in an interview.
“They hear the stall alarm but show no signs of having recognized it,” he said. “At no point is the word ‘stall’ ever mentioned.”"
“They hear the stall alarm but show no signs of having recognized it,” he said. “At no point is the word ‘stall’ ever mentioned.”"
Join Date: Mar 2001
Location: us
Posts: 694
Likes: 0
Received 0 Likes
on
0 Posts
Yaw String, the crew went to SELCAL mode at 0135. After that time, they did not reply to several queries from ATLANTICO. They thus would have missed any communications between ATLANTICO and the LH ahead of them regarding its deviation on encountering the MCC.
Was it prudent behavior going to SELCAL mode flying into a SIGMET area, and after receiving the following from dispatch?
The yet-to-be-released portion of the CVR may have the answer.
The PF had performed five rotations in the South America sector since arriving in the A330/A340 division in 2008, including one to Rio de Janeiro.
The PNF had performed 39 rotations on the South America sector since arriving in the A330/A340 division in 2002.
The Captain had carried out sixteen rotations in the South America sector since he arrived in the A330/A340 division in 2007.
The data released to date do not indicate how many rotations occurred during the different seasonal variations of ITCZ activity in the South Atlantic..
Was it prudent behavior going to SELCAL mode flying into a SIGMET area, and after receiving the following from dispatch?
at 0 h 31 dispatch sent the following message:
“BONJOUR AF447
METEO EN ROUTE SAILOR :
o PHOTO SAT DE 0000Z : CONVECTION ZCIT SALPU/TASIL
o PREVI CAT : NIL
SLTS DISPATCH”,
“BONJOUR AF447
METEO EN ROUTE SAILOR :
o PHOTO SAT DE 0000Z : CONVECTION ZCIT SALPU/TASIL
o PREVI CAT : NIL
SLTS DISPATCH”,
The PF had performed five rotations in the South America sector since arriving in the A330/A340 division in 2008, including one to Rio de Janeiro.
The PNF had performed 39 rotations on the South America sector since arriving in the A330/A340 division in 2002.
The Captain had carried out sixteen rotations in the South America sector since he arrived in the A330/A340 division in 2007.
The data released to date do not indicate how many rotations occurred during the different seasonal variations of ITCZ activity in the South Atlantic..
Join Date: Oct 2006
Location: Gone Flying...
Age: 63
Posts: 270
Likes: 0
Received 0 Likes
on
0 Posts
SaturnV:
SELCAL mode is not a question of being prudent or not. Its a question of VHF comm range. When we go into SELCAL we normally keep the last VHF comm freq selected until loosing full contact with the previous ATC and then select 123.45 on VHF 1. (VHF 2 on 121.50).
Was it prudent behavior going to SELCAL mode flying into a SIGMET area, and after receiving the following from dispatch?
Quote:
at 0 h 31 dispatch sent the following message:
“BONJOUR AF447
METEO EN ROUTE SAILOR :
o PHOTO SAT DE 0000Z : CONVECTION ZCIT SALPU/TASIL
o PREVI CAT : NIL
SLTS DISPATCH”,
Quote:
at 0 h 31 dispatch sent the following message:
“BONJOUR AF447
METEO EN ROUTE SAILOR :
o PHOTO SAT DE 0000Z : CONVECTION ZCIT SALPU/TASIL
o PREVI CAT : NIL
SLTS DISPATCH”,
Was it prudent behavior going to SELCAL mode flying into a SIGMET area
I do agree with Yaw String - we all need to help each other via VHF on the Oceanic Sectors......
Join Date: Jun 2009
Location: California
Age: 54
Posts: 203
Likes: 0
Received 0 Likes
on
0 Posts
SaturnV
Delta T, the Lufthansa at 350 that preceded AF447 by 20 minutes on UN873 deviated 10 NM to the west. The Iberia following AF447 by 12 minutes was at 370 and deviated by 30 NM to the east. AF459 (an A330-203) following the Iberia by 25 minutes deviated first by 20 NM to the west, and then 70 to 80 NM to the east of the track, and was given permission to climb to 370. Neither the Lufthansa or Iberia deviations would have significantly affected fuel consumption.
AF459 at the time of its deviation would have been unaware that various centers were trying to contact AF447. (DAKAR contacted AF459 at 0411 asking it to try and contact AF447.)
Delta T, the Lufthansa at 350 that preceded AF447 by 20 minutes on UN873 deviated 10 NM to the west. The Iberia following AF447 by 12 minutes was at 370 and deviated by 30 NM to the east. AF459 (an A330-203) following the Iberia by 25 minutes deviated first by 20 NM to the west, and then 70 to 80 NM to the east of the track, and was given permission to climb to 370. Neither the Lufthansa or Iberia deviations would have significantly affected fuel consumption.
AF459 at the time of its deviation would have been unaware that various centers were trying to contact AF447. (DAKAR contacted AF459 at 0411 asking it to try and contact AF447.)
Some alarmingly uninformed questions about fuel by other posters. To clarify transport aircraft always carry contingency fuel for deviations. My assertion is that the flight before and the flight after had prior to departure filed a modified flight plan to deviate around the storm. In doing so they took on extra fuel in addition to the contingency fuel. Any talk about the head office refusing a Capt extra fuel is absurd.
It is remarkable that AF447 showed no signs of significant deviation up to the point of the incident. IMHO this implies they were unaware of the storm system at least until they were in it. Did they get the wrong pre flight weather or simply omit it?
I don't believe any transport pilot would choose to take a center line path through a large storm given advance notice and the ease of a deviation. Would not having known of the storm also tie in with the bewildering fact that the Capt took rest immediately before entering the storm. I would want to look at a transcript of the pre-flight briefing to see if the storm was mentioned. Relatively minor mistakes early on (e.g. pre-flight) can snowball events down the road.
Join Date: Jan 2008
Location: UK
Age: 69
Posts: 292
Likes: 0
Received 0 Likes
on
0 Posts
Relatively minor mistakes early on (e.g. pre-flight) can snowball events down the road.
For Graybeard and about AoA Probes and indications
Graybeard, in re "better" AoA indicators. I'll suggest to you that the US Navy has been using one "better" (actually, I doubt it's any better) from before I started flying which functions reilably at airspeeds below 60 knots. (There is one on the T-34C Trainer that works as you describe ... a weather vane in the horizontal plane. See also AoA probes on various Navy jets).
I don't think it's the probe that's the issue, but a software decision on signal processing. You could do what you need to (no stall chirp on the ground) with a WoW switch (already have one on the bird, yes?) without artificially clipping the AoA signal when in flight.
Your comments, sir?
I don't think it's the probe that's the issue, but a software decision on signal processing. You could do what you need to (no stall chirp on the ground) with a WoW switch (already have one on the bird, yes?) without artificially clipping the AoA signal when in flight.
Your comments, sir?
Last edited by Lonewolf_50; 1st Jun 2011 at 17:54.
About Pilot Training and Simulators
Originally Posted by from that article in Der Spiegel
Von Jeinsen's motion is primarily based on the expert opinion of Gerhard Hüttig, a professor at the Institute of Aeronautics and Astronautics at the Technical University in Berlin.
Just over a year ago, Hüttig recreated the Air France crash in a flight simulator. In the course of the exercise, Hüttig noticed a strange anomaly in the plane's reaction once it goes into a stall. The trimmable horizontal stabilizer, a flap instrumental in keeping the plane on an even keel, automatically adjusted to push the nose of the plane skyward.
Hüttig, a former Airbus pilot himself, and other pilots present for the test were unable to push the nose of the airplane down and thereby escape the stall.
Just over a year ago, Hüttig recreated the Air France crash in a flight simulator. In the course of the exercise, Hüttig noticed a strange anomaly in the plane's reaction once it goes into a stall. The trimmable horizontal stabilizer, a flap instrumental in keeping the plane on an even keel, automatically adjusted to push the nose of the plane skyward.
Hüttig, a former Airbus pilot himself, and other pilots present for the test were unable to push the nose of the airplane down and thereby escape the stall.
What is unknown to me is how well the sim replicates stall for that aircraft. A number of sage Airbus pilots, who have also taught in sims, have pointed out (in the Tech Log Discussions) thta lacking the data points from extended flight test, programming data points into the sim for stalled or other "outside the envelope" flight conditions is a bit of a guessing game. It can lead to negative training due to anomalies NOT present in the aircraft being experienced in training in the sim.
While Hüttig doubtless understands this, please consider the report on his findings to be provisional. See also that the champion for this position is an attorney involved in an action ... tread with care here.
A few other points.
Pattern is full made an important observation a few pages back about displayed speed. For an interval there (about a minute?), what is on the FDR may not be the airmass flow that the wings, rudder, the THS saw. So, what is on record for BEA to analyze has to account for "data" points that are known to be erroneous for some of the time before and after the upset.
Q: The stall warning discontinued when the speed was BELOW 60 Kts. How in blazes do you fly a large jet at 35000 ft at a speed of 60 Kts ??
Q: If the IAS gets down to 60 Kts and the wheels are not on the ground then the aircraft must be very badly stalled. Disabling the stall warning makes no sense.
This is not a feature, it is a bloody stupid design error.
This is not a feature, it is a bloody stupid design error.
If the stall warning sounds all pilots are trained from PPL level to expect it to continue until the stall has been recovered. Stopping the horn while the aircraft is still stalled is dangerously misleading and IMHO is a major contributing factor in this accident.
Originally Posted by Capn Bloggs
Good? Stall warning stops when the speeds are invalid?
Great system. If the AoA indicates the wing is stalled, it should keep going, regardless of the speed.
Great system. If the AoA indicates the wing is stalled, it should keep going, regardless of the speed.
Originally Posted by Flight Safety
Q: If you don't trust the PDF and all the magic, isn't this what the ISIS is for? Also, what were the engines doing at IDLE only 70 seconds or so after they commanded TOGA power?
They must have really been confused.
They must have really been confused.
Thought for Flight Saftey: confusion looks to have begun early in the event, when the PF had the A/P off and ended up in a climb. That looks to me like a symptom of primary instrument scan breakdown. If, and I repeat IF, his attitude indicator (pitch and roll / artificial horizon) was working, it appears that PF made a transition while not using attitude indicator as primary scan. Since we don't know what PF was seeing, that is a provisional hypothesis, quite possibly wrong.
Originally Posted by jet driver
To all out there, if you think your airlines have trained their pilots sufficiently for the most complex failures you are sadly mistaken or kidding yourselves. In the corporate, commercial environment accidents like these are at best " acceptable " damage ( one in 10 million chance, or one in 100 million chance ratinale ). Anything you hear about safety from airline higher ups are nothing but posturing, outright lies and utter baloney.
Are we stupid, then? We train constantly for all sorts of situations... Or could here be a training deficiency?
If you have/were never trained in hand flying close to the ‘edges’ of an envelope (or even outside an envelope), or if you have never actually been hand flying close to the ‘outside’ of an envelope, chances are that you won’t even notice that you’re going out... Whilst thinking you’re ‘hanging in there’... And so far, so good...
Are we stupid, then? We train constantly for all sorts of situations... Or could here be a training deficiency?
If you have/were never trained in hand flying close to the ‘edges’ of an envelope (or even outside an envelope), or if you have never actually been hand flying close to the ‘outside’ of an envelope, chances are that you won’t even notice that you’re going out... Whilst thinking you’re ‘hanging in there’... And so far, so good...
Given the generally successful departure and arrival rates, maybe the public is willing to accept the very, very small risk of this "imnperfect storm" of events creating a flying catastrophe.
Originally Posted by comment, forget who
Actually if you have time ( they didn't ) you can call up AOA in the CMC maintenance pages.
Just change the page and location the computer is sending it to.
If you have a warning "revert to manual trim" can you not also find some real estate for "AoA = XX.X? "
This does not seem hard, but actually it is. Figuring out where in a display package this goes is a non-trivial process, since there is X area for display and a lot of different information that pilots use or need.
Originally Posted by Guildenstern
Is it possible to get a stall warning when pulling out of a dive?
The latter killed a colleague of mine a couple of decades ago.
Join Date: May 2008
Location: UK
Posts: 200
Likes: 0
Received 0 Likes
on
0 Posts
More questions: Doomed Flight AF 447: Questions Raised about Airbus Automated Control System - SPIEGEL ONLINE - News - International
EDIT: Bad info.
EDIT: Bad info.
Last edited by ECAM_Actions; 1st Jun 2011 at 18:18.
ECAMS:
As I understand the FC diagrams, Alt Law has auto trim for elevators and THS, you go to manual trim in Direct law for the THS. If I am reading that wrong, please advise.
From the diagram, it appears to me that elevator trim may not be operating in Direct law, but I may be wrong on that.
Here are the words ... (from an out of date summary of A 330 systems)
•
As I understand the FC diagrams, Alt Law has auto trim for elevators and THS, you go to manual trim in Direct law for the THS. If I am reading that wrong, please advise.
From the diagram, it appears to me that elevator trim may not be operating in Direct law, but I may be wrong on that.
Here are the words ... (from an out of date summary of A 330 systems)
Alternate Law
• No change for
ground, take-off and flare mode compared to Normal Law.
•
Flight mode :
Pitch axis : as per Normal Law with limited pitch rate and gains depending on speed and CONF.
- Roll/yaw axes : Depending on failure :
•
Flight mode :
Pitch axis : as per Normal Law with limited pitch rate and gains depending on speed and CONF.
- Roll/yaw axes : Depending on failure :
1. The lateral control is similar to normal law (no positive spiral stability is introduced).
2. Characterized by a direct stick-to-roll surface relationship which is configuration dependent
2. Characterized by a direct stick-to-roll surface relationship which is configuration dependent
•
Protections :
- pitch attitude : lost
- high speed : replaced by static stability
- high angle of attack : replaced by static stability
(Vc prot. Law) + aural stall warning when
- high speed : replaced by static stability
- high angle of attack : replaced by static stability
(Vc prot. Law) + aural stall warning when
α > α sw*
- low energy : lost
Direct Law
• No change for
ground mode and take-off mode compared to Normal Law.
• Flight mode : Maintained down to the ground in all three axes, direct relationship between stick and elevator/roll control surfaces which is center of gravity and configuration dependent.
• Flight mode : Maintained down to the ground in all three axes, direct relationship between stick and elevator/roll control surfaces which is center of gravity and configuration dependent.
•
All protections are lost
Conventional aural stall and overspeed warnings are provided as for Alternate Law.
• Main operational aspect :
• Main operational aspect :
- manual trimming
through trim wheel.
Last edited by Lonewolf_50; 1st Jun 2011 at 18:18.
Join Date: May 2008
Location: UK
Posts: 200
Likes: 0
Received 0 Likes
on
0 Posts
@Lonewolf: you are right. In ALTN LAW there is auto THS.
Low Speed Stability will attempt to pitch the nose down to maintain just above Vls, but the pilot *CAN* override this (maybe that is why the PF was pulling up - he was stopping the nose from dropping in the belief they were flying and the systems thought they weren't due to the low airspeed reading?).
Low Speed Stability will attempt to pitch the nose down to maintain just above Vls, but the pilot *CAN* override this (maybe that is why the PF was pulling up - he was stopping the nose from dropping in the belief they were flying and the systems thought they weren't due to the low airspeed reading?).