FE Power Forums

FE Power Forums => Non-FE Discussion Forum => Topic started by: jayb on May 27, 2011, 06:14:02 PM

Title: Air France crash
Post by: jayb on May 27, 2011, 06:14:02 PM
Any of you guys follow aviation-related topics?  I'm always interested in finding out more about what causes crashes, and today some interesting data became available from the flight data recorder of the ill-fated Air France flight from Brazil to Europe.  This flight crashed inexplicably in the summer of 2009, and based on some automated signals from the plane before it crashed, indications were that the pitot tubes (which provide airspeed information) may have malfunctioned.  The crash was in the middle of the Atlantic, and for a long time the flight data recorders were not found, but recently they were both recovered and went to France for analysis. 

Turns out that the plane was not getting good airspeed data; stall warnings came on and off a couple times, and finally the airspeed read as an extremely high value.  But the plane basically stalled at a very high altitude, and fell, without flying, all the way to the ocean.  While this was going on the pilots were trying to hold the nose of the plane up, indicating that they thought they were going to fast, not too slow; normally you put the nose down to fly out of a stall.

Its a very strange situation, and I'm looking forward to the further analysis on this by the aviation authorities.  I can think of several possible scenarios that could be the root cause of the crash:

- Loss of most instrumentation, including airspeed and the artificial horizon.  In a storm this would make it nearly impossible to understand where you were and what the plane was doing.

- Computer lock up, where the computer that is responsible for most of the plane's functions took bad data from the airspeed indicator and did not allow the pilots to properly control the airplane.

- Pilot error, where the pilots misinterpreted the available data and controlled the airplane incorrectly.

Anybody else have thoughts on this?
Title: Re: Air France crash
Post by: ToddK on May 27, 2011, 07:34:26 PM
I've been following this crash and investigation with a bit of interest, as I fly the same aircraft type, Airbus A330's for a living.

There has been a lot of speculation about the causes of this crash, but hopefully now they have recovered the data recorders we will get a definitive answer. However, recently Airbus released a revised procedure to deal with unreliable airspeed indications as well as how to handle stall warnings. These revised procedures reinforced the basics of flying in that if you set a known power and a known attitude, the aircraft will fly a known performance. From this, it has been speculated that there may have been a mishandling of the recovery procedure of the unreliable airspeed indications that it appears the AF aircraft suffered.

The modern Airbus aircraft has a complex flight control system that is computer controlled or "fly by wire". There are no direct control cables running from the cockpit to the control surfaces. It has 3 primary and 2 secondary computers that control the flight surfaces, and these computers operate in various states of flight control law, depending on the phase of flight and the level of equipment and data serviceability. So when things start going wrong, like having pitot tubes blocking or AOA sensors failing, which leads to faulty information coming from the Air Data computers, the flight control computers try to decide which information is correct by comparing the data from all the inputs. A problem can arise when only one data input is correct, but 2 other data inputs are the same but in error, the flight control computers will use the faulty data. It then becomes the pilot's job to disconnect all the autopilots, auto thrust and flight directors and fly the aircraft the same way you were taught to fly your first basic training type, so you can recover the aircraft to a stable and safe flight path and then hopefully sort out the data problems and recover the aircraft safely to land.

I really feel uncomfortable when any sort of aircraft crash or incident where there has been a loss of life gets attributed to pilot error, as it shows either a lack of training or lack of understanding of the principles of flying. In this case, I believe the AF training system is quite good, better than a lot of other carriers around the world who I would not allow either my family or myself to travel on. So, maybe if the AF crash does come down to mishandling, the crew were caught unaware or just had a bad day. Which just shows how unforgiving the aviation industry can be - have one bad day and so much loss of life can follow. But hopefully, when that bad day does come around, the guys up front flying have had enough training and experience to deal with the situation correctly.
Title: Re: Air France crash
Post by: jayb on May 27, 2011, 08:54:52 PM
Wow, great to have a real expert on the board!  Todd, do you think it is possible that the inputs to the computers were faulty, and the pilots didn't recognize this and as a result did not put the controls in full manual mode?  I imagine that in the dark, in a turbulent storm, and with a bunch of faulty instrument readings, discerning what the aircraft is really doing could be rather difficult.

I'm guessing that China Air is at the top of your no-fly list...
Title: Re: Air France crash
Post by: ToddK on May 27, 2011, 09:34:35 PM
Yes, China Air and Air China are both up there.

With the way the Airbus flight control logic and laws work, it is quite easy to get the aircraft into a divergent stability type situation by trying to override the protections for stall/overspeed that are built in, with manual control inputs.

When you have a definite overspeed situation, the recommended procedure is to select a lower commanded airspeed and allow the autothrust to reduce the power. However, if you go into a large overspeed the autopilot will disconnect. With the aural warning for the overspeed warning going off, the autopilot disconnect aural warning can be missed. Even though the autopilot has disconnected, the built in high speed protection will command a nose up pitch to try and reduce the airspeed. Once the airspeed has recovered below maximum, the flight controls will go out of protection mode and back to normal. However, if you are not aware that the autopliot has disconnected, then you can get into trouble. Also, if in the heat of the moment, with warnings going off, you disconnect the autothrust and bring the power back to idle, you now have the engines at idle and airspeed can bleed off quickly. So you can see how a mishandled overspeed can quickly turn into a bad situation. A few months back, the domestic branch of the company I work for had a mishandled overspeed due to clear air turbulence in the cruise. The autopilot and autothrust selected off, and it didn't take long before the pilot flying got the aircraft into an upset situation and they lost altitude as well as hurting some passengers and crew in the cabin. Luckily they recovered and landed safely. But it just shows how easily things can turn into a real can of worms in an Airbus.

Now, everything I wrote above is predicated on the air data that is being displayed is accurate. If you start throwing corrupted air data into the equation, things are a different situation. In the case where air data is corrupted and not recognised by the computer systems, the faulty data will be displayed on the cockpit instruments. This is where pilots must rely on their basic flying skills to first control the aircraft, and then identify the faulty source and take corrective action. If this event occured in the middle of the night, in a storm, and you have all sorts of warnings going off, it can be a very distracting environment, making a hard job even more difficult.

From what I have read so far about the AF crash, the aircraft was intact when it hit the water. I'm not sure on it's flight path on impact, but again I have heard that they almost pancaked onto the water. This may indicate they were close to recovering, but ran out of altitude. Again, this is just rumour and speculation, we won't know for sure until the full investigation is released.
Title: Re: Air France crash
Post by: Kerry j on May 28, 2011, 06:26:51 AM
I've been following this story too and while I don't fly the kind of iron Todd does, I have had some experience trying to control an aircraft with corrupt air data info. I had an incident a few years ago where the pito static system of my plane froze up because of a faulty pito heat circuit breaker. I had some help because it was not at night and I was talking to ATC and they alerted me to the fact that I was climbing and slowing down; because I was not staying at my assigned altitude. I also had taken simulator training and the instructor had played a trick on me trying to make me crash. He turned my 58P Baron into a R44 helicopter after I took off; LOL! He slowed down slower and slower and I was scrambling to discover what the problem was.

Anyway, because of the help from ATC and the prior sim experience, it really helped me focus on flying the plane first with the best data I had. In that case I started using my GPS ground speed as my primary source of data; I could tell if I was descending or climbing by watching the ground speed. I finally figured out what the problem was, opened the alternate air source and got the breaker to stay closed so that the pito system thawed out.

I can see how in the middle of the atlantic at night how having to deal with corrupt air data would be difficult if not impossible to deal with in a plane like the Airbus. And it makes me uneasy that new aircraft like the Airbus do not have a manual back up system for the computer and fly by wire systems so that in a case like this, the pilots have no alternate source of data or control available.
Title: Re: Air France crash
Post by: WConley on May 28, 2011, 11:25:47 AM
I'm an engineer with a background in aeronautical and control systems.  I too have been following this story closely!  :'(

As the systems become more complex, how do we ensure that a pilot has what he needs in an emergency?  I don't know...  Remember the Aeroperu 757 that crashed because maintenance had taped over the pitot-static ports?

http://www.airdisaster.com/cgi-bin/view_details.cgi?date=10021996&reg=N52AW&airline=Aeroperu

There are lots of big brains working on this problem, but I don't see how you can manage every failure mode on such a massive system.  Could a battery-powered GPS device be an effective last-ditch information source, as it was for Kerry?

Title: Re: Air France crash
Post by: Cyclone03 on May 28, 2011, 01:49:30 PM
I'm at the low end of the other responders above....
I work Aircraft Avionics. I have limited experience with large aircraft as I've only worked US Air Force trainers, currently the T6 Texan II which is all glass cockpit with a single ADC (Air Data Computer). Previously I worked the T1 Jayhawk an aircraft with dual ADC's.
On the T1 we had trouble when the AF first got them,~1992,in normal operation the #1 and #2 ADC would operate separately giving the pilot and co pilot flight data info, including Altitude, airspeed ,vertical  velocity, attitude and navigation display. Each "side" had it's own pitot, static and temp sensors. Two problems arose fairly quickly, in normal operation the ADC operated separately, sort of, because they are linked and they compare and average there output displays .So during ground preflight checks the crew will operate each side separately to verify each side operates within limits. The standby system, basically "manual" altitude, airspeed and attitude indicators gets it's pitot pressures from the #2 pitot tube, same as the #2ADC.The problem was if the #2 Pitot system had a fault in flight it would relay that (pressure) info to the #2 ADC and we would have an ADC fault because the #1 and #2 systems are out of range of each other. The early checklist noted to verify flight info using the standby indicators, well as you can see if the #2 pitot system is at fault but is believed to be correct things can turn bad quickly. The "fix" was more  procedural  than an actual fix,the checklist was changed to isolate the ADC's to verify which system was at fault ,but still a double pitot failure would remove most of the available cockpit flight info leaving just GPS for airspeed and altitude. The Attitude should be indicated by the Standby by ADI (attitude indicator) as it has a built in GYRO.
Ground control could help with some info, but it would be delayed at best. More like trend recording.

I don't know if the AB ADC's read the stanby indicators but if they,AF,had a double Pitot failure and the pilots could not disable the FDC and ADC and fly off the stadby indicators and GPS then they where hosed for sure. Basicly they confirmed the fears of every pilot of  fly by wire aircraft. What happens if ALL the input DATA is corrupt, and the computers don't let the pilot take control of the aircraft?
Title: Re: Air France crash
Post by: Kerry j on May 30, 2011, 09:28:22 AM
More on the Air France Airbus crash; just got this article in my email:

http://www.avweb.com/eletter/archives/avflash/1920-full.html#204731

You have to scroll up a bit to see the Air France article.

I just don't understand how an experienced pilot would or could hold the stick at full nose up attitude for 3 minutes. They knew they were in trouble were scrambling for answers, yet the guy kept the plane in a deep stall for 3 minutes by holding the stick at the stops; full nose up. Makes no sense to me. But then I have no idea what kind of training the pilots had prior. Maybe they never flew a small plane and practiced stall recovery or how to recognize a stall and were totally dependent on the computerized flight and air data system. If that's the case; there needs to be a major change in the way these pilots are trained. Get back to basics and the associated maneuvers pilots should learn at the beginning of their training.

Very sad that so many had to die because the pilots didn't know enough to pitch down, level the plane and fly it.
Title: Re: Air France crash
Post by: ToddK on May 30, 2011, 06:47:26 PM
It is very sad indeed that so many lives were lost in this accident, and even more so because it looks like it is attributable to pilot mishandling.

Apparently, AF447 was not the only flight using that airway that night. A number of previous flights had diverted around the area in which the bad storm involved in the accident was located. Which prompts the question, was the AF flight's radar system working correctly, or was it not adjusted correctly? Or worst still, was it just not being monitored? When the aircraft entered the storm, the captain was taking rest and not in the cockpit. I'm not sure of the experience level of the pilots who where at the controls.

As Kerry mentioned, it does lead to questions about the level of training involved in some airline pilots these days. I know in the company I work for, which operates a fleet of 100+ wide body passenger and freighter aircraft all around the world, there is a marked difference in the experience levels of the pilots. We have pilots like myself who had an extensive background in military flying before I joined this company. And we also have pilots who joined the company's cadet scheme with no flying experience, did 200 hours basic training in light aircraft, and were then employed as a second officer for the next 2 to 4 years where they are used as cruise relief pilots. In that capacity, they do not manipulate the controls of the aircraft, apart from doing regular simulator training. Quite a number of the guys have made it through the system and are now captains with the airline. So they obviously meet the training requirements. But they still have no depth of knowledge or background experience from their past aviation life. All they know is this company's rules and procedures. And it often shows in their ability to think outside the box when confronted with a situation that is "not normal". And the company I work for is not the only one that has pilots like this working for it, it is quite prevalent at most major airlines. And these days with the growing number of low cost carriers, this situation of lower paid and less experienced pilots flying you around is going to increase.

Sorry about the rant, I'll get off my soapbox now. The guys involved in the AF crash may have all been very experienced, I don't know, and were just overwhelmed. But it does make you wonder how it could have happened.
Title: Re: Air France crash
Post by: Kerry j on May 30, 2011, 10:30:19 PM
Todd, the article says the pilot who had the controls had 3000 hours of logged flight time. That's almost as much time as I have and I've been flying since 1987. What it doesn't say is what kind of flight time that 3000 hours was made up of; as you mentioned, there is a vast difference in how savvy and analytical different pilots can be with the same number of hours. I know many CFI's who have many more hours logged than I do, but they have precious little real world experience in actual IFR conditions. They have 2000 hours of right seat time in the pattern watching primary students try to learn to fly the Cessna 152. Doesn't really translate into valuable flight time IMO.

I don't want to cast dispersions on the flight crew of 447; but it just seem inconceivable how a certified pilot with real world flight time could hold the stick full back for 3 minutes and not even consider it to be the problem. And to make things even worse, they did retard the throttles from full take off power to flight idle for a time, but still never lowered the nose. It is to my way of thinking beyond belief how they could do that.
Title: Re: Air France crash
Post by: ToddK on May 31, 2011, 01:35:04 AM
I agree, it is quite disconcerting to think about what happened and why.

These following few paragraphs were just released by the union I am a member of. It summarises the France's Bureau dÉnquetes et dÁnalyses (BEA).
"It appears that the most junior pilot with only one year’s experience on the A330 was the PF the FO
as PM in the left seat with the Captain resting in the cabin. The pilots attempted to deviate around
weather and soon thereafter got conflicting flight instrument information. As the information varied and
became contradictory (between PFD1 and the ISIS) the aircraft reverted to Alternate Law. For the non-
Airbus readers this means that the Flight Computers can no longer provide certain protections, such
as stall and overspeed, as the flight computers have no way of ensuring their inputs are accurate. This
effectively turns the A330 into a 744 in that the pilots are now responsible for ensuring the aircraft does
not overspeed or stall. In Alternate Law the A330 will similarly provide stall or overspeed (aural) warnings
but without the stick shaker associated with a 744 stall.
From the BEA report it appears that after the reversion to Alternate Law, the aircraft was pitched to a high
nose attitude climbing 3,000ft, from 35,000’ to 38,000’. This placed the aircraft into an ‘aerodynamic stall’.
For the next few minutes, angle of attack was in excess of 35 degrees with a ROD of over 10,000 fpm. It
appears that from the initial ‘upset’ to impact with the Atlantic Ocean was approximately three and a half
minutes.
It is quite sobering reading this initial report. Obviously, the potential for disorientation is high, flying unacclimatized
and operating through your Window of Circadian Low whilst getting unusual warnings and
failures. It is times like this that the basics from flight school must come to the fore: Power + Attitude =
Performance.
The cause of the crash is still being investigated. Many hypothesise that the pitot tubes may have iced up
leading to the erroneous and conflicting flight instrument indications. Of note, this incident led to the first
fatality involving the A330 in passenger service in almost 15 years of passenger operation."

An explanation of some of the terminology:
PF - pilot flying, the nominated pilot who has control of the aircraft
PM - pilot monitoring, the support or co-pilot
PFD - primary flight display, in a glass cockpit it shows attitude, airspeed/mach, altitude, VS and heading, as well as the flight director and other information
ISIS - intergrated standby instrument system, the standby attitude, airspeed/mach, altitude and VS indications
Title: Re: Air France crash
Post by: BarryB on June 01, 2011, 12:58:34 PM
Wow! I didn't see this thread until now. FWIW, Air France from a maintenance P.O.V. is top-notch. Flight-ops, not so much. I dealt with them on a daily basis in Mirabel (Montreal) a few years ago. The flight crews were arrogant beyond words, I'm okay with that but it was readily apparent that any sense of CRM
(Cockpit Resource Management) was not a priority, at all. At that time I saw operations on B747-200, B747-300, B747-400, B747F, B767-300 and the occasional A310-300. They had 28 flight/week at that time, I saw them a lot. The captain's word was god, period. 
My day-to-day role these days is an AME (Aircraft Maintenance Engineer) with the occasional stint as a heavy maintenance tech rep on B737NG's.

This is a great thread on a Canadian bullboard about this crash. I've been on here for years.

http://theairlinewebsite.com/index.php/topic/391344-why-did-air-france-447-go-down/
Title: Re: Air France crash
Post by: Kerry j on June 06, 2011, 09:14:07 AM
More thoughts and insight from an experienced A320 pilot:

http://www.avweb.com/eletter/archives/avflash/1925-full.html#204773

Some very good insight as to how this could have happened.

http://www.avweb.com/avwebflash/news/air_france_447_investigators_stall_crash_204730-1.html

It was inconceivable to me how they could hold the nose up at 3 - 13 degrees pitch for so long and no one even consider it to be a problem. Until I read this experienced A320 pilots comments. It makes a lot more sense now how easy it would be to overcontrol the aircraft and how hand flying the plane is rarely if ever practiced.

Sounds to me like there needs to be some systems overhaul on the aircraft and much more attention to training in case of a systems failure = hand flying the plane with limited data input. Something beginning or learning IFR pilots to on a regular basis; fly the plane by hand with partial panel.
Title: Re: Air France crash
Post by: jayb on June 06, 2011, 11:10:34 AM
Back in my model airplane days I used to fly with a guy who flew 767s and 747s for Northwest.  He also trained on the A320, and he commented once to me that with the Boeing planes the throttle levers always moved to reflect what the engines were actually doing, while the Airbus throttle levers did not.  He said he used to watch the throttle levers on his 767 out of the corner of his eye while performing certain actions in the cockpit; I've long forgotten the details, but he felt that having the throttle levers moving was an important feedback mechanism for the pilot, and he felt a little blind without that on the Airbus.

What the pilot in your link said sounds kind of like the same thing.  It is kind of beginning to sound to me like Airbus "dumbed down" their planes too much to make them easy to fly in manual mode.
Title: Re: Air France crash
Post by: Kerry j on June 06, 2011, 10:58:13 PM
The throttles would be hard for me to deal with, but having a joy stick that requires such small inputs while giving no feedback, would be impossible to deal with unless all the instruments were working. I've had a lot of partial panel time while under the hood doing the training my insurance company requires and it would be impossible to keep an aircraft under control with partial panel and the aircraft set up like the that A320 pilot describes how the A320's are.

There are techniques that are taught which really help you keep the aircraft under control if some of your instruments quit, but those techniques use airspeed, compass and yoke feedback to give you an alternate picture of what's going on. And with some practice you can hold altitude and heading without having the use of the ADI. How one would do that with no feedback from the yoke and throttles and no reliable speed indication; I do not know.
Title: Re: Air France crash
Post by: ToddK on June 08, 2011, 07:46:44 PM
When I converted to the Airbus, I came off of 12 years of flying Boeing 707's, 747-200's and 747-400's, as well as 10 years of military flying before that, so the change to the Airbus set up was quite big for me. However, the side stick is quite nice to fly with. It did take me a little time to get used to having no control feed back, however there is no need to trim the controls on the Airbus. Just set the attitude required and let the stick go, it will stay there. Small control inputs are required, I find it a lot like the control inputs we used in close formation flying I did in the military. The control system is good and does work well, but it does make a lot more sense when the design philosophy behind it is explained to you.

As for the non moving thrust levers, again that took a little while to get used to. But again, once the design philosophy is explained, it makes sense. When the autothrust system is engaged, it works well, so there is no need for the thrust levers to move. If you want to know what the thrust is doing, there are clear trend lines on the EPR/N1 gauges. And if you disconnect the auto thrust, the thrust levers operate in normal fashion. Personally, if the conditions at landing are anything other calm wind, I prefer to fly a manual thrust approach, as I feel I can have better control over the airspeed and thrust that way. However, that is just a personal preference, a hangover to my background flying I guess. But the Airbus autothrust system is good and capable.
Title: Re: Air France crash
Post by: Kerry j on June 09, 2011, 06:57:08 AM
I agree about the side stick Todd, I've flown aircraft that have them and it's really easy to get accustomed to. First time I flew a Cirrus, I was comfortable with in within a few minutes.

The thing I have a hard time with is the lack of feedback from both the side stick and throttles in the A320 when there's a problem with the data the pilots have to use to fly the plane. How are they supposed to keep the damn thing in the air when the data system is compromised and they're IFR?
Title: Re: Air France crash
Post by: cjetmech on June 17, 2011, 05:29:01 PM
Heres an article I just read in aviationweek http://www.aviationweek.com/aw/generic/story.jsp?id=news/awst/2011/06/06/AW_06_06_2011_p36-330706.xml&channel=comm   
 Pretty interesting because it says at one point they recovered and got their instruments back but put it into a stall again. I'm a tech so I dont know but can one of the pilots on here tell me if stalls are ever practiced in the sim. It seems like they are not.
Title: Re: Air France crash
Post by: ToddK on June 17, 2011, 06:17:55 PM
I do recall once practicing a fully developed stall and recovery in the simulator during my initial A330 conversion. But nothing since then, although we do practice recoveries from stall warnings. The stall warning is still short of a fully developed stall.
Title: Re: Air France crash
Post by: cjetmech on June 18, 2011, 06:15:58 AM
Wow thanks for the info Todd. I had always thought upset recovery was part of sim training. I wonder if after these recent incidents, (especially Colgan) company's / or the feds start requiring this type of stuff as part of a type rating?
Title: Re: Air France crash
Post by: ToddK on June 18, 2011, 06:49:36 PM
In the company I work for, we do our licence and instrument rating renewals every 6 months in the simulator. That involves 2 sim sessions each time, a recurrent training sessions and then the actual rating renewal. In the recurrent training session, they usually  throw in anything topical or something the safety department has highlighted as worth practicing. In the past it has been things like volcanic ash encounters, wind shear or visual approaches. I dare say in the next session or so we will be practicing upset recoveries with instrument failures.
Title: Re: Air France crash
Post by: BarryB on June 20, 2011, 11:37:12 PM
The company I work for has no sim training for upset recovery although I understand that that is being considered.
I really don't know how it can't NOT be done actually. Colgan air and Air France were two that should have been recoverable. There was also the US air crash in 1994 with a full-over rudder jam that was subsequently trained for in the B737 fleets of the world.
easy to say from here though. I wasn't there and I'm not a pilot. I just fix 'em!
Title: Re: Air France crash
Post by: BarryB on June 22, 2011, 10:24:09 AM
http://atwonline.com/operations-maintenance/article/limiting-loss-control-0401
Title: Re: Air France crash
Post by: jayb on August 01, 2011, 01:55:21 PM
The latest report on the Air France crash is summarized here:

http://www.ainonline.com/news/single-news-page/article/latest-report-on-af447-crash-calls-for-new-training-and-flight-data-30753/

It sounds like malfunctioning equipment created a situation where the pilots weren't sure what was going on.  The BEA claims the situation was "salvageable", implying pilot error, but Air France seems to disagree, specifically citing the on/off nature of the stall warning as something that confused the crew, and kept them from taking proper actions.  In any case, it sounds like the pilots for this aircraft will be getting more training on manually flying the airplane, and the airplane itself will be getting an angle of attack indicator.  I'm kind of surprised that an angle of attack indicator isn't already installed on the plane...
Title: Re: Air France crash
Post by: ToddK on August 01, 2011, 07:16:22 PM
The A330/340 aircraft do have 3 angle of attack sensors, however there is no direct reading of AOA displayed in the cockpit. The AOA readings are used by the flight management, guidance and envelope computers. The only indication the pilot has of AOA is, under normal flight law, when the AOA is greater than a protection limit value. This is indicated by the airspeed reducing into a low threshold band, and also autopilot disconnecting and the thrust increasing to TOGA. However, in the case of the AF incident, if the airspeed readout was incorrect, the flight controls may not have been in normal law, so a lot of the built in protection would not have been available. But even without any AOA indication, there still would have been stall indications such as airframe buffet, not to mention an unusually high nose up pitch shown on the attitude indicator.

It is unfortunate to read this report as it is really starting to sound like it was a recoverable situation that was badly mishandled and led to the death of so many people. Whether the airline it self or the aircraft manufacturer is also to blame, that's for the courts to decide. But regardless of whatever systemic causes will be blamed for this accident occuring, when the shit hits the fan, it's the 2 pilots up the front who have the responsibility of recovering the situation and safely landing the aircraft. So it annoys me when airline management claim that pilots are glorified, over paid bus drivers and they try to cut our wages and conditions. Sure, they can hire guys who will work for peanuts. But wouldn't the travelling public want the most experienced, best qualified crew flying their aircraft. I know I would if my family were travelling by air.

Sorry about my rant there, but it is something that gets on my nerves. These days we see so many low cost carriers all trying to compete, and they go to all sorts of measures to reduce operating costs. Most of the public see low, low air fares and think it's great. But when their flights get delayed or cancelled and they get stranded, or worst case, there is a safety incident, then the same public complains about it. But it's the same as buying car parts - you buy the cheapest part now, it may not be that cheap in the long run.

Okay, I'll get off my soapbox now and back on topic...
Title: Re: Air France crash
Post by: jayb on August 02, 2011, 07:47:25 AM
Thanks for the clarification on the angle of attack indicator.  As my friend who flies the A320 says, pilots should get paid for the responsibility that they take when flying the plane, and that is basically putting the lives of the passengers in the pilot's hands.  I don't  understand the rationale for chopping pilot's salaries either; it will only attract less qualified individuals to the field  :'(
Title: Re: Air France crash
Post by: billballinger on August 04, 2011, 06:34:07 AM
I am not an expert, but I wondered about something.  If the tubes themselves were in a stall, such as an atmospheric vacuum, could they possibly supply data that is out of range and disregarded by by instrumentation and flight systems? A vacuum would essentially be like putting tape over them, and if the barometric pressure and position of the tubes were to come together in a certain alignment, could they possibly become a vacuum situation that would render them unreliable?  I am postulating that if this critical element were in error, everything down the line would be a domino effect of computer errors that would compromise the integrity of the entire flight system, and information that the pilot is receiving instrumentally.  It would not necessarily be pilot error, but instrument failure. 

I am looking forward to hearing more also.       
Title: Re: Air France crash
Post by: WConley on December 09, 2011, 01:01:28 AM
Here's a new article that summarizes the events in the cockpit.  Gripping read!!

http://www.popularmechanics.com/technology/aviation/crashes/what-really-happened-aboard-air-france-447-6611877

- Bill
Title: Re: Air France crash
Post by: Kerry j on December 09, 2011, 08:10:31 AM
Hard to imagine holding back-pressure on the yoke for so long and not have a clue what you're doing. Seems like a serious flaw in the training of that co-pilot. What he did is completely foreign to any flight training I've had or heard of; it is just drilled into you to keep the nose down and the co-pilot held the nose up for more than 3 minutes.

Another thing this points out is the need for standard electric or vacuum driven "steam" attitude indicator and gauges as backup to the flat screens & electronic systems the industry has become ennaoroed with.

Very sad that 228 people had to die because of such a basic mistake in understanding of their situation and application of proper input.
Title: Re: Air France crash
Post by: machoneman on December 09, 2011, 09:38:58 AM
Thanks for posting that PM article. Very sad indeed that at so many points of possible intervention the pilot, co-pilots and their training let down, fatally, so many passengers. I wonder too if the cockpit crew 'grew up' as I'll call it around light planes where manual flight controls, spins, stalls, etc. could have been part of a training regime on 'what to do if'. Bet they didn't!


 

Title: Re: Air France crash
Post by: WConley on December 09, 2011, 10:28:29 AM
From what I have read elsewhere, high altitude stall recovery hasn't been part of normal airline crew training in the past.  It is a vastly different scenario from low-speed stall recovery, where getting the nose down and applying power is generally a good thing.

At high altitude cruise, it's much easier to bend the airframe or get into an overspeed situation with the "standard" procedure.  The engines aren't making as much thrust either, so you have to use a lot of altitude. 

It looks like new training procedures for high altitude stall recovery are being implemented as a result of this incident.
Title: Re: Air France crash
Post by: Garyford on December 24, 2011, 06:13:38 PM

Thanks for posting this.  Not to make light of a tragic situation but it is an interesting combination that could explain some of life's other failings:


1) the young pilot was already nervous, which the article states might have blanked out creative thinking. In retrospect on bad situations one might wonder "what were you thinking" when in fact, that part of the brain might be shut down.
 
2) some of the Controls don't give feedback, so the young pilot might have been unaware he was pulling back.  Apparently the human mind is capable of blanking out a stall alarm so he might have similarly blanked out the notion he was pulling back on the stick. Very frustrating to read that part, but the article partially explains it as a human defense mechanism.
 
3) the senior pilot wasn't communicated the joystick position. Assumption is he had no idea the stick was pulled back and would have immediately recognized the error with with minimum feedback.


A bit humbling to read
Title: Re: Air France crash
Post by: ToddK on December 24, 2011, 06:54:35 PM
As a bit of an aside issue, but something that should be of concern for every future air travelled. In an attempt to reduce the cost of training and secure enough pilots for expansion, airlines around the world are looking at cadet schemes where they take a person off the street, give them 250 hours in a simulator and then they are straight into the right hand seat of an airliner carrying passengers. It's already happening in some low cost carriers in our region, and some of the larger carriers, including the one I work for, are also looking into it. Scary stuff.