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Quote... The passengers, who had just a short time before been pressed into the backs of their seats, were now being held into their seats only by their seatbelts. "At this moment, I would have feared for my life even if I was sitting in the passenger cabin," said one A330 pilot after reading the BEA report. That the plane was in freefall would have been clear to all on board. The nose of the plane pointed skyward at an angle of 16 degrees. "That's more than immediately following takeoff," the pilot said. Unquote. Having flown many times and thinking about my built-in senses of horizontal and gravitational, I tend to agree. The passengers were never pressed into the backs of their seats, since the aircraft was losing speed. They were never held only by their seatbelts, since that would require negative G's, which they never would have seen as a result of the maneuvers described in the BEA "note". The initial pitch up would not have been much different than experienced when rotating for taking off. The ride over the top would have certainly been noticed, when they went from a high rate of climb to high rate of descent, but passenger's behinds would have always been solidly in their seats, not dangling from their seatbelts, as suggested in the article. Once descending, the rate of descent didn't change, so passengers would have only sensed that the nose was pointed up, somewhat like an initial climbout on takeoff on say a DC-10 or 757. There also would have been heavy buffeting. Given that they were flying at night in a storm, the passengers would have had no outside references to know what was happening, and would not have known they were falling. A clue would have been the change in cabin pressure, but how many passengers would connect that with rapid descent? To me the unanswered question is then - why didn't the pilots realise they were pointed up towards the sky and they were falling like a leaf? They could see the altitude bleading away extremely rapidly. Could they not read the attitude also? At least they knew they were pulling up! It seems ridiculous in hindsight that pulling up over that length of time and not reducing the descent MUST only mean you are not diving, you are stalled. Easy to say now, but those guys are supposed to be professionals, yes? |
Quote: Quote:
The manufacturer Thales was well aware of the catastrophic consequences of a failure of the speed sensors as early as 2005. At the time, the French company concluded that such a failure could "cause plane crashes." A total of 32 cases are known in which A330 crews got into difficulties because the speed sensors failed. In all the cases, the planes had pitot sensors from Thales, which were significantly more prone to failure than a rival model from an American manufacturer. But none of the responsible parties intervened. In 2007, Airbus merely "recommended" that the sensors be replaced. Air France took that as a reason not to carry out the costly work -- and it even got official blessing for doing so. The European Aviation Safety Agency wrote that it currently saw "no unsafe condition that warrants a mandatory modification of the Thales pitot tubes." Money is in play here, I'm sure. Typically, if the component maker or airframe builder make a Service Bulletin mandatory, they pay for it. If the SB is optional, the airline pays. I've known airlines who refuse to pay for SB that are to correct defects, regardless. As to why they did nothing for two years, consider that they were told that there was no safety problem by both the manufacturer and the regulator, and they must have agreed, so why do anything? It's not as though pitot tubes are that expensive when compared to other costs. It was only after a few other incidents that they took action on their own to start the replacements. |
On a Dutch news site here ( Inmiddels 77 lichamen uit ) the following claim is made (translated into English): Quote: The pilots wanted, thus becomes clear from the 'current conclusions' from the investigation into the two black boxes of the plane, to fly over a lightning storm, but were prevented from this because it wasn't possible due to the temperature to fly to that height. Reading this kind of surprised me, as I didn't have the impression that they wanted to fly over the storm, but it would explain why they suddenly went into this steep climb. 31st May 2011 07:50 |
ST27
"The PF knew he was pulling up, but are you sure the PNF knew it? It's not quite as obvious what the other guy is doing with sidesticks, particularly if you are concentrating on a checklist." It took me three pages to catch up and catch this statement, the rest mostly rehash, argument, etc. Inferred in this statement are some very basic questions as to where cockpit management and aviating clash. If it turns out that PF was handling the situation poorly (and we have no idea if that is the case), then we have single pilot crew. Not trashing that concept, but ST27 points to a fundamental flaw (perhaps?) in allowing (mandating) a review of procedures developed by folks who were clueless re: the situation to hand. A fully qualified Pilot, rather than assisting in the aviating, is doing a checklist that arguably has no bearing on the current problem(s). Additionally, the procedure requires to distract the PF from his focus? Here is an identified evidence of the Airline, the Manufacturer, the a/c, and the F/O distracting the recovery. At all times by the book, or memory of the book. PF and F/O were writing a new book, and the old book was horning in, inexcusably. So in preventing the popular conclusion that all responsible parties were remotely engaged in sabotage by reflex, perhaps the authority will give it up? Secrecy is Power, make no mistake, and at some time, even the apologists for the archaic dance of power will have to become vocal. Other than to say, "it is complicated". Thanks to ST27 bear |
Some people are better than others at maintaining good situational awareness. I would not belittle training and experience. But even very experienced pilots can become disorientated, as indicated by many sad examples among the accident investigation reports I have studied over the years.
Therefore, IMHO, any instrument which might work counter-intuitively in unusual circumstances, significantly increases the risk of disorientation and its associated consequences if those unusual circumstances should arise. It remains my tentative view that the stall warning (the one at 2h10min51, perhaps; but mainly the one at 2h1202-17) could well have seemed to indicate that the nose-down inputs were for some reason causing the aeroplane to enter a stall, so discouraging the PF from developing the very inputs which might have led to an exit from the stall. According to the preliminary report the angle of attack "n’est pas présentée aux pilotes": ie, the instruments did not include an AoA indicator. No longer trusting the airspeed or other indicators ("je n’ai plus aucune indication", and "on n’a aucune indication qui soit valable") it may have seemed to the PF that he faced two risks: going too fast for the airframe, or going too slow for the AoA. He seems to have discounted the second of those risks despite the stall warnings. So stated, this was an irrational response. Therefore, it is probable that something made it appear rational at the time. I suggest that he discounted it partly because of the stall warnings or, rather, because of the timing of the stall warnings and their seeming linkage to his nose-down commands. |
As to why they did nothing for two years, consider that they were told that there was no safety problem by both the manufacturer and the regulator, and they must have agreed, so why do anything? It's not as though pitot tubes are that expensive when compared to other costs. It was only after a few other incidents that they took action on their own to start the replacements. |
000tfm000
For the present, the times are merely landmarks, suggestive only of snapshots of aspect, response, input, etc. Just prior the Stall Warning that the pilot is rumored to have disobeyed, he is trending out of a high deck angle, and accelerating. This is the result of a Stall, and he will have known that he is in a Stall. Now you may argue that the alert (only an alert) has dissuaded him from continuing the recovery. Given the sparse frame work of such an argument, I will say that to be 'dissuaded from continued recovery' in the midst of physical cues that affirm it, defames our PF further. Counsel? |
It remains my tentative view that the stall warning (the one at 2h10min51, perhaps; but mainly the one at 2h1202-17) could well have seemed to indicate that the nose-down inputs were for some reason causing the aeroplane to enter a stall, so discouraging the PF from developing the very inputs which might have led to an exit from the stall. The second one was, but here no further information about what happened in the next 1m30s is given at all. Maybe he was discouraged, but maybe he kept pushing ND to no avail. We simply don't know because the report doesn't say. |
From ST27:
Once descending, the rate of descent didn't change, so passengers would have only sensed that the nose was pointed up, somewhat like an initial climbout on takeoff on say a DC-10 or 757. There also would have been heavy buffeting. Given that they were flying at night in a storm, the passengers would have had no outside references to know what was happening, and would not have known they were falling. A clue would have been the change in cabin pressure, but how many passengers would connect that with rapid descent? From ST27: More rubbish from Der Spiegel. Air France was in the process of changing out the pitot tubes. They received their first shipment of replacement parts a week before the accident, but had not applied them to that particular aircraft. |
Who was PF?
A number of news articles have stated that the PF was the relief pilot, who was the youngest of the crew, had the least amount of experience on type (800 hrs), and the least total flying time. If that is true, and with the captain going for rest, that would leave the FO as PNF. The FO had the most time on type of all the crew (4500 hrs).
None of the BEA reports have stated who was flying at the time of the upset. Perhaps the media obtained the information as a result of a leak. However, this arrangement seems odd to me. Can anyone familiar with how work would be assigned on trans-ocean flights comment on whether this would be a typical assignment, given that they were about to fly into the ITCZ? |
For example, there is not enough informations to understand why the A330 climbed and stalled at 38 000 ft : > the pilot gives «ordres à cabrer» (pitch-up orders) > then the PF gives «ordres à piquer» (pitch-down orders) Now, I also think that the report is missing some information but the BEA has shared when power settings changed. After the initial AP/THR discconect, no mention of a power change is made - so it is probably at the setting for FL350 and M0.8. The first input is a pilot commanded climb with a max recorded rate of 7,000ft/min. By the time they reached FL375 nose down had reduced that rate of ascent to 700ft/min (I believe that the plane was still climbing at that point albeit much slower than initially). Without an increase in thrust, there is a trade of speed for altitude. Most likely pilot commanded but turbulence/updrafts may have played a part too. I think if there was an intent to climb over any weather then a thrust setting change would have been made by the PF and none is noted by the BEA. At 2h10m51s the stall warn sounded. It probably hasn't stalled at this point - the BEA indicates the last 3m30s were stalled and the recording finished at 2h14m28s. That makes the stall a 'fact' at 2h10m58. John. |
Who was PF?
According to this article, Bonin was the PF. As you suggest this could very well be pure speculation on the part of the journalist - or possibly based on a leak? 'Baby' pilot at controls of doomed Air France Airbus | The Australian
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Deliberate climb to get out of icing but with no reliable speed mismanaged thrust ?
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Elledan, the Dutch news site is wrong. To be sure of climbing over an ITCZ "lightning storm," the AF flight crew would have to have assumed they might well have to climb as high as 55,000 feet or so, and to do that, they'd have needed the Space Shuttle, not an Airbus. Their sudden climb to 380 had nothing to do with any attempt to top a thunderstorm. The current conclusion seems to draw towards pilot error with equipment failures and gaps in training as likely contributions. The nose-up inputs especially seem beyond merely curious. I really wonder whether there might be anything about that on the CVR. |
Can anyone familiar with how work would be assigned on trans-ocean flights comment on whether this would be a typical assignment, given that they were about to fly into the ITCZ? ST27 is online now Report Post Reply Clearly in the Air France case the experienced first officer as PNF should have taken control immediately things went wrong. Of course there was no guarantee the F/O could have saved the aircraft either but the political correctness of "my leg" needs to be examined. In my era the captain would at his discretion offer the F/O a take off and/ or a landing. It was never a case of "your leg" with all that implies. It was always the captain's "leg". Every sector was under the command of the captain and supported by his F/O. Now it is almost seen as an insult to the first officer if the captain decides to take over control of the F/O's "leg". In the case of the Air France accident it is this politically correct mind-set that may have caused the real first officer to assume the subordinate role as PNF while the second officer lost control of the situation. |
This is indeed an interesting observation, worthy of a study in itself. Where I work, we have a general inkling that CRM has gone 'bonkers'. It certainly was baffling to me why the Captain did not jump back into the seat and 'take over', until explained this way...
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Yeah, that's what I figured. Pilots can fly around a storm, but they can't fly over one. In my years as ATC the one I remember best was a transatlantic bound 747 from a major European airline (now defunct) who decided against the 60-80NM dogleg that everyone else was doing to avoid a line of CBs above Belgium. He asked to climb to FL390 to keep its route , then when above dropped down 5 or 6 thousanfds feet right inside. His voice was shaken afterwards. The incident report must still be out somewhere. 2 weeks a go an A320 tried the same thing above Germany, with same results. 3xmayday, dropped 4000ft etc.. Rare events , sure ,but not unheard of. |
Allocation of (PF) flight legs to crew.
A37575:
It is not a right that every other leg belongs to the F / O or 2nd Captain. It is the Commander's decision to allocate the legs, if he wants to. The decision of the Captain, to go to the "bunk" so early in the flight seems strange to me, however he must have had a reason. |
The decision of the Captain, to go to the "bunk" so early in the flight seems strange to me, however he must have had a reason. On the broader issue of him being "off watch" during the ITCZ crossing, personally, I think you have to take into account the fact that he left two fully rated pilots up front - not cruise only copilots. If we're saying a Captain shouldn't ever leave the Flight Deck because inclement weather is forecast in the cruise how do we suggest handling say, traversing Asia or Indonesia during the monsoon season or the North Atlantic if there's forecast of occasional severe CAT all the way across the pond......two Captain ops/no in flight rest :eek:???? (BTW am I alone in often not being able to see the last page of the thread?) |
Dumb question
Maybe a dumb question from a dumb SLF - wouldn't it make sense to have a mechanism that blows into the Pitot tube from the inside to test if it is clogged? If there is higher resistance than its clogged and disregard readings. Maybe it can also be cleaned that way...?
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Originally Posted by 000tfm000
Some people are better than others at maintaining good situational awareness. I would not belittle training and experience. But even very experienced pilots can become disorientated, as indicated by many sad examples among the accident investigation reports I have studied over the years.
Therefore, IMHO, any instrument which might work counter-intuitively in unusual circumstances, significantly increases the risk of disorientation and its associated consequences if those unusual circumstances should arise. It remains my tentative view that the stall warning (the one at 2h10min51, perhaps; but mainly the one at 2h1202-17) could well have seemed to indicate that the nose-down inputs were for some reason causing the aeroplane to enter a stall, so discouraging the PF from developing the very inputs which might have led to an exit from the stall. I really don't know where to start with this thread. So much noise, so little signal. The number of red herrings and long irrelevant side tracks is so great that no one can even start to address them. The PF quickly and correctly diagnosed the situation. Loss of airspeed indication, resulting in AP/AT off and Alternate Law. He then incorrectly pitched up to 10° until the AoA was just 2° from the stall. In this perilous position, the AoA increased again to 6° and the aircraft stalled. The response was incorrect with TOGA + pitch up. So, two apparent errors. So much has been said about the wrong procedure being used (TOGA + pitch up is used in many other procedures) and a lack of training that I won't bother. But here is something frightening: Most older Airbus pilots have done their time in cranky old jets and turboprops, where you fly by pitch. Everything is done by pitch settings - choosing, setting, adjusting, waiting and so on. However, in the world of the safety committee it is fine to pluck young lads straight from a Seneca and place them into an Airbus. To mitigate the risk, the flight director must be on at all times. Now all the cadet has to do is put the square in the centre of the cross. Never has a pitch been noticed nor noted. I asked 5 first officers in the cruise to look me in the eye and tell me what pitch we were at (2.5°). 4 cadets answered between 5° and 10° :ooh:, and one ex TP guy answered correctly at 3°. Not much of a sample, but indicative I suspect. The Airbus is a fine aircraft. It is conventional, and simple. On top is a thick layer of cotton wool, that should protect us from our silly mistakes. Once the cotton wool is removed, we are back into a simple jet. The snag is that with the current drive to train/recruit people as quickly and cheaply as possible, not one of the recent arrivals has ever flown in "simple jet mode" (by pitch and thrust). Incredibly in our airline it is now even prohibited to take off with the flight directors off. I feel sorry for the two FOs on the flight deck. Without the FD they will have been in new territory. Without the airspeed, it is no time to have to guess pitch settings and develop a strategy to keep the thing in the air. I hope the airlines have a good think about this. I imagine the safety departments will, but nothing will happen due to the cost of recruiting people with experience on conventional types. PS: Below 60 knots I imagine the stall warning is inhibited because there is not enough airflow over the AoA vane to make it accurate and trustworthy. PPS: Has any Airbus pilot here ever actually heard the stall warning in the sim? |
Hi,
(BTW am I alone in often not being able to see the last page of the thread?) Sometime it's more than 1 false "last page" :) |
I asked 5 first officers in the cruise to look me in the eye and tell me what pitch we were at (2.5°). 4 cadets answered between 5° and 10° |
To mitigate the risk, the flight director must be on at all times. Now all the cadet has to do is put the square in the centre of the cross. Never has a pitch been noticed nor noted. |
Hi,
There also would have been heavy buffeting. Given that they were flying at night in a storm, the passengers would have had no outside references to know what was happening, and would not have known they were falling. A clue would have been the change in cabin pressure, but how many passengers would connect that with rapid descent? But passengers also have ears to listen ... and I am than most (at least those who were not asleep or woke up) will have noticed changes in engine speed .. and it will have more of a worry about .. even if they did not know that the plane was heading towards the sea Moreover, I wonder what that could be displayed on the seats screens ..... |
(BTW am I alone in often not being able to see the last page of the thread?) |
PS: Below 60 knots I imagine the stall warning is inhibited because there is not enough airflow over the AoA vane to make it accurate and trustworthy. |
It is not a right that every other leg belongs to the F / O or 2nd Captain. |
Yellow Pen,
I over egged. The flight director must now be on for take off and initial climb out. It may be off for an ILS if conditions are suitable, and will be off for hand flown visuals. However with the level of inexperience we now have, not many captains will be so happy at the thought of a <500 hour pilot flying a raw data ILS, when most approaches and landings with a full house of aids can be just a tiny bit "variable". We have an industry wide reputation for having an excellent training department. However we (like many other airlines) now refuse to recruit experienced first officers, and restrict ourselves to Seneca -> Airbus low hour contract first officers. Hence my point - many recent Airbus pilots may have no experience of flying a jet on pitch and thrust alone. |
grimmrad: wouldn't it make sense to have a mechanism that blows into the Pitot tube from the inside |
I'd say if a 200,000-kilo plane is in the air, and at less than 60 kts, it is stalled, regardless of whether the AoA vanes are trustworthy at that speed.
The Stall warning logic should be "if the plane is not on its wheels, and the AoA vanes indicate a stall, then the warning sounds. It ALSO sounds if the plane is not on its wheels and the AoA vanes have reached their maximum reliable point (even if no longer trustworthy)." I'll concede that an A330 in the air at 60 kts is improbable - but the improbable is what warning systems are intended for. _________________________ RE: the reported quote from the Captain "We're in a stall, REDUCE power and pitch." I take it that has to do with the A330's low under-wing engines? A high power setting (or rapid power increase) would cause more pitch-up, making it harder to lower the nose and break the stall? We've seen that noted in the case of 737 stalls or go-around incidents. Usually, stall recovery involves INCREASED power. |
Hundredpercent
You nailed it ! This is exactly what it is along with a twist of over confidence. I'm sorry but 2 F/O's at the front, even if qualified ( WTF does it mean anyway ? ) is not the same as a skipper and a F/O. When the captain is on the flight deck, there a clear chain of command. There is also at least 15 years difference of dealing with crappy flight conditions and I'm sorry, like it or not, that makes a hell of a difference. It's become a very touchy issue where F/O feel insulted whenever they're told they are not as " good " as the old man in the left hand seat. Again, it has nothing to do with " good " or " bad". Commnanding a flight is a job that one learns and creams with experience. A sprinkle of humility sweets it nicely too. What some airlines need to do is to acknowledge there is a gap that needs to be filled and very pronto. Lufthansa has a Senior First Officer training syllabus where emphasis is put on leadership and left hand seat handling of the aircraft in emergency situations. The roles are very clear when the Captain is in the bunk. Others have second first officer which is another way of clearly stating who does what under who's authority. So to say that 2 fully qualified pilots are the same is just ludicrous. If the debate remains an egotic one, I'm afraid we're not going to very far and to finish : Yes !!! I think the Captain has to arrange his breake so as to be in his seat for the tricky part of the flight and as to 447 I am damn sure the outcome would have been very different had the Captian been on the flight deck for the reason Onehundredpercent so elloquently explained. |
True airspeed fell to 60 knots or not?
Surely the IAS only fell to 60 knots during the icing of the pitots? I don't think the a/c's true airspeed ever fell that low or am I wrong? An in-flight IAS of 60 knots will always be considered UAS if I understand the FBW 'logic'.
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Yes !!! I think the Captain has to arrange his breake so as to be in his seat for the tricky part of the flight So what are we defining as "tricky, and therefore captain must be in his/her seat weather"? Look at a Longhaul sigmet chart for, say, Asia and the subcontinent in the monsoon season...where's the "tricky part of the flight"? Probably starts at SIN maybe ends at Karachi, and then there's the "tricky" high ground and the "tricky" comms, around Kabul, oh and then after that the inevitable CBs (with associated severe turbulence of course) around Moscow or the Crimea and the dire warnings about being very careful if deviating in Russian airspace.."tricky" or not? Again a sigmet chart for the North Atlantic will quite often show that the NAT tracks are planned to pass through or very near to areas of forecast Moderate to Severe CAT..so by some definitions the whole of the Atlantic could be "tricky" on some nights. If your are seriously going to mandate/insist that the Captain must be in his seat for the "tricky part" of every flight, irrespective of the qualifications and/or experience of the other pilots, how are you going to do it/pay for it? BTW I've no problems with two captains on a three pilot augmented crew if that's your answer :ok: |
Wiggy,
You may, perhaps, be being facetious with your suggestion, but, as a Captain, I think it would increase my chance of sleeping from "no bloody way" to "yeah I might nod off" were it to be adopted. My current ops involves moderately long 2 sector night ops with the "official duty" involving me "sleeping":D for a bit in Row 1-3. Well,let me tell you, I don't, I do go back,so as not to ruffle feathers, and probably I never will manage to zzzz, so it is as well that I don't make too many of them in a month. In God (& Pratt & Whitney, what about CFM?) we trust, the rest? :hmm: := NFW ! ! |
Who design that ?
Quote: (BTW am I alone in often not being able to see the last page of the thread?) Aside to wiggy - No, you aren't alone. But it just a forum housekeeping thing. As Page 59 (e.g.) gets nearly full, an empty Page 60 gets created. But until the posts actually flow over to page 60, you can't get to it (and there's nothing yet to see anyway). http://images.ibsrv.net/ibsrv/res/sr...ser_online.gif Is it Boeing or Airbus ! :{ |
What am I looking at?I asked 5 first officers in the cruise to look me in the eye and
When 80% of first officers think like that , surely they must be a product of the "Sausage Factory" training system.
There are many of these type of training schools in the antipodes. |
The 'extra' pages are for the posts that the mods have deleted. The trick is to look at the post number of the last post on the page. If the number of the post is devidible by 20,chances are there is another page to read!;)
ie this was the last post at the time of posting. |
What should a PF bet on : instruments or human thinking ?
Hi Meccano
JJFC If you KNOW an instrument is faulty - are you seriously suggesting we follow it? I hope I'm misunderstanding you here, because any pilot is potentially 100% more reliable than a faulty instrument! And unfortunately it's not always clear cut. Contradictory indications often occur. Which instrument to believe then??
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IMHO I think flight data monitoring has been a factor in the demise of flying skills. Unfortunate as it is, the same experienced Captains who used to let f/os fill their boots and learn under their informed guidance, now are sick of newbie flight managers who use the tool to berate the smallest indiscretion and tend now not to take the risk. Sadly I believe the pilotless flight may as well be introduced.
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