Can anyone explain the (what looks like) scorching marks on the separation line just aft of the door ?
http://i.telegraph.co.uk/multimedia/...e_3163123b.jpg |
The constant reference to "beancounters" as a threat to airline safety is a bit fanciful. It's not the accountants' fault if safety standards are insufficient.
If there are failings (the evidence isn't convincing) then the problem is regulation and enforcement. From food to finance, we have seen constant pressure on funding to regulators during the past few decades (not to mention the busting of unions). It wasn't beancounters who did this — it was right-wing ideologues. |
Originally Posted by ACLS65
(Post 8823873)
It is also things like FTC and STC to reduce clutter and I am sure lots of digital processing now.
"Sensitivity Time Control (STC). This feature reduces the impact of returns from sea state. It reduces the minimum SNR of the receiver for a short duration immediately after each pulse is transmitted. The effect of adjusting the STC is to reduce the clutter on the display in the region directly around the transmitter. The greater the value of STC, the greater the range from the transmitter in which clutter will be removed. However, an excessive STC will blank out potential returns close to the transmitter. Fast Time Constant (FTC). This feature is designed to reduce the effect of long duration returns that come from rain. This processing requires that strength of the return signal must change quickly over it duration. Since rain occurs over and extended area, it will produce a long, steady return. The FTC processing will filter these returns out of the display. Only pulses that rise and fall quickly will be displayed. In technical terms, FTC is a differentiator, meaning it determines the rate of change in the signal, which it then uses to discriminate pulses which are not changing rapidly." Radar Systems island_airphoto Anyone who wants to see radar freq. vs. rain can take a look here: https://www.youtube.com/watch?v=RvTkVj5-uv0 This isn't POWER, it is FREQUENCY. The approaches suggested in research are variants of multisensor tracking where a complete 4D picture is built up using ground radars. See NSSL Projects: Multi-Radar/Multi-Sensor System (MRMS). These pictures may then be sent to the flight deck through Aircraft Access to SWIM (System Wide Information Management). This is in the Continental United States. It may be that other areas could do the same but it is expensive. Other approaches have looked at taking all the aircraft radars and mosaicing them into a 4D picture. But again someone has to do it and then find someone willing to pay for it. Guess what the beancounters won't hear of it. |
Originally Posted by oblivia
(Post 8824086)
The constant reference to "beancounters" as a threat to airline safety is a bit fanciful. It's not the accountants' fault if safety standards are insufficient.
If there are failings (the evidence isn't convincing) then the problem is regulation and enforcement. From food to finance, we have seen constant pressure on funding to regulators during the past few decades (not to mention the busting of unions). It wasn't beancounters who did this — it was right-wing ideologues. In consequence, the accountants do not see any ROI for their area in what is being suggested and advise strongly against the proposals. As someone said upthread - in reality money always comes before safety its pointless spending so much money that the airline fails. The result is that the use of ROI for some aviation aspects has to be trumped by mandate from the authorities. The accountants (aka beancounters) will then look around for savings and an easy area is training. This is why highly automated aircraft were sold based on the reduction in training. It is why there is pressure for unmanned or single manned aircraft. |
Iain_W These approaches will reduce the clutter in the returned signal but they do not change the attenuation of the radar outbound or reflected signal as it passes through rain. If the rain is heavy enough the radar signal will literally not get through. There are things that can be played with like changing the polarization of the radar signal but they don't solve the attenuation problem. An analogy is dense fog - To radar rain is like dense fog you can play with yellow headlights or blue headlights but if the fog is dense enough you will not be able to increase the visibility by a lot. The approaches suggested in research are variants of multisensor tracking where a complete 4D picture is built up using ground radars. See NSSL Projects: Multi-Radar/Multi-Sensor System (MRMS). These pictures may then be sent to the flight deck through Aircraft Access to SWIM (System Wide Information Management). This is in the Continental United States. It may be that other areas could do the same but it is expensive. Other approaches have looked at taking all the aircraft radars and mosaicing them into a 4D picture. But again someone has to do it and then find someone willing to pay for it. Guess what the beancounters won't hear of it. http://cup.aos.wisc.edu/will/im_and_durden2005.pdf Every new technology faces the cost vs benefit decision, but if accidents prove to have been avoidable the cost has a way of becoming affordable. |
let's keep something in perspective, if a pilot does not know you push the stick forward to get out of a stall, he shouldn't be flying a plane. There have been failures in instrumentation, quite often information processing overload, and turbulent weather initiation of disastrous events. All of this usually happening in IMC with no references. There appears to be a need to improve pilot training as regards loss of important instrumentation, and for them to be able to handle degradation of automation. However, to place blame simplistically as in your description, is unreasonable and misleading. The training areas obviously needing upgrading, is to try and remove any confusion over what the aircraft is actually doing, when the pilots have little reference in severe turbulence, plus a loss of important instrumentation. I'll wager Captain and FO confusion will be found to be important factors in the crash of QZ8501. |
To HarryMan - irks and life in the office
this idea that every single step anyone takes or nut & bolt wasting away in astore always needs costing and charging (to someone or some budget or other) irks me. really, not exactly proactive forward thinking govt. And what better exercises and real life experience & training is there than being out there and doing stuff.. rather than twiddling fingers in offices ... ... it could have been many years for the full facts of metal fatigue's random scatter to be fully accounted for in design. |
AirAsia SAR Operations to End
After 17-days, news today that the principal Search and Rescue operation will be terminated soon. Gen. Bambang Soelistyo, head of the National SAR agency (BASARNAS), declined to answer when exactly SAR operations will wind down, but it is expected to be in the next 3 or 4 days. National SAR may continue more limited "day to day" operations out of respect and consideration for the victims' families. Once the SAR phase ends, any further searches will focus solely on recovery. It is unclear whether the Indonesian Army (TNI) will take over the search effort from BASARNAS, or if it will be conducted under the jurisdiction of Indonesia's National Transportation Safety Committee. Until now, the joint SAR team has located only 48 remains (out of the 162 souls on board). Of those, 36 remains have been identified and released to the families. Meanwhile, 12 other remains are still awaiting the identification process. |
We all know how easy it is to recover from a stall. All pilots learn that before they are released for their first solo. You learn stall recovery in the first 10 hours of your PPL flight training.
What pilots are now experiencing with complex aircraft is a new situation where, due to the complex design nature of their aircraft, they instantly don't know what the aircraft itself is doing. So in an abnormal situation, as in the one which lead to AF447, we have the situation where 3 qualified pilots were baffled with what was happening to the aircraft. You have about 3 to 4 minutes to work out what's going on, and then to deal with it, or else it's game over. Would I be right in saying, AF447 was the first instance, of a deep stall ever experienced by a FBW Airbus aircraft? No-one has ever been in a similar position before? If the aircraft had been a non FBW A300 or A310, would the outcome have been different? |
WSSS
I really think the captain on AF447 DID KNOW what was going on, he just wasn't in one of the chairs . I would not call AF447 a deep stall. Deep Stall has been sort of reserved for T tail planes...though some may have other thoughts. |
WSSS
My understanding of a deep stall is to describe a state where the elevators become inoperable due to insufficient airflow and the aircraft cannot pitch out of the stall. This happens more in T tails because the disturbed air from the wings catches the tail at a certain angle, but I suppose if any heavy aircraft is below a certain speed then elevator deflection may not be sufficient to move the AOA - you need to roll as well. |
@Ian W
The accountants (aka beancounters) will then look around for savings and an easy area is training. |
Unstalling a wing is very simple, decrease the AOA to less than the stall AOA. 1. Too late You need enough aerodynamics on your elevator. You might not have it when in a deep stall, or when you are way too slow already. 2. Too little You need the authority by the FBW. Its action computers might not have enough travel to cope. 3. Too 'magentised' You need the authority of the protections. They might be fooled by sensors and not allow unloading, and/or they might be too complicated to override ...... 4. Too inexperienced You need the guy at the stick realise that he's in a stall! Even with 20k hours he might have been told this can't happen, or he might have never experienced such a situation, just read in the OM what to do in case the thing happens that can't happen per superior design ...... Pick your numbers, they pretty much apply for many of the latest accidents. |
if any heavy aircraft is below a certain speed then elevator deflection may not be sufficient to move the AOA - you need to roll as well. |
WSSS: I truly doubt that FBW had anything to do with this incident.
"We all know how easy it is to recover from a stall. All pilots learn that before they are released for their first solo. You learn stall recovery in the first 10 hours of your PPL flight training." Many argue that "true flying skills" are no longer present in today's younger pilots due to FBW and the video game mindset. I believe that the problem is more the fact that since the days of the 727, the concept of the "coffin corner" is no longer taught. You can't just climb as aggressively in the thin air as you can at a lower altitude without stalling. A stall in PPL training with a fat wing, in fat air is an easy fix. Max power, lower the nose some. And you are never trained in full stalls again. I was trained in the jet only the "approach to stall recovery", It wasn't till several of our company aircraft entered moderate stalls at high altitude that that they trained us in the proper recovery. I was shocked at the altitude loss and pitch attitude required for recovery. And still, few airlines teach this in the sim. |
Cabin positions of victims recovered thus far:
https://mobile.twitter.com/TheNewOce...904448/photo/1 |
It wasn't till several of our company aircraft entered moderate stalls at high altitude that that they trained us in the proper recovery.I was shocked at the altitude loss and pitch attitude required for recovery. And still, few airlines teach this in the sim. Is this not the basis for Airbus reluctance to do sims on real stalls, that they do not have the data required to make the training meaningful/realistic and that they prefer to train to avoid the stalls in the first place. Did the pilot-engineered stall on AF447 provide any useful data for an Airbus sim? The problem possibly being that there was no recovery and that at some stage a "recovery" might have "torn the wings off" anyway? |
Crash position indicators are a solved problem.
Crash position indicators a the result of research into ejectable radio beacons that would deploy in a crash. The problem was solved 60 years ago and implemented first in military aircraft five decades ago. I'm not sure what this forum's policy is on Wikipedia, but this is worth a look.
Crash position indicator - Wikipedia, the free encyclopedia |
If not push, just release the backpressure I truly doubt that FBW had anything to do with this incident Because of this, FBW has quite a lot to do with any incident/accident involving the flight controls, as it is always more than just replacing control cables with electric wires. It is a different control system requiring different flying technique. Quite similar to the difference between powered flight controls and pure mechanic ones. Backpressure on a DC-3 is quite different from backpressure on a 747... And still, few airlines teach this in the sim. they prefer to train to avoid the stalls in the first place. We should also remember that the regulation is not asking for spin recovery of multi engine aircraft or stall recovery of large transport aircraft. All that is required is recovery from the situation when the warning is triggered. It is not required to fly full stalls in flight testing. And matter of fact, several prototypes were lost during stall testing in the past, so it is probably wiser to avoid it altogether. |
To say "Pilots were trained" for Stall Recoveries in their PPL phase, and expect that to have any relevance years later, when both time has passed, and flying very different aircraft, is not valid IMHO
In my RAF days, exercises such as stall recoveries were required to be practiced, IIRC, every 28 days. Along with UP recoveries etc. From my experience, the 3 yearly "training cycle" of such items in typical airline Sims, and also the "canned" / tame nature of the exercises, renders them nigh on useless :ooh: I reckon the "benefits" of being refreshed last for maybe 2-3 months, then I think I am back where I was prior the sim. There is little point in practicing "stall recoveries" unless and until we are proficient in recovering at the approach to the stall. And of course if we are proficient at the recovery at the warning stage, there is less merit in practicing the full stall & recovery. Does anyone seriously believe the AF447 pilots had any chance of recovering once they got to <60KIAS / 40 AoA? Yes - the aircraft was theoretically recoverable, but given how they got to that point, I think the chance was almost nil. They had so seriously lost SA that the very bold control inputs and attitudes required I do not see happening? The solution, if we wish to reduce LoC accidents (which are very rare), is to ensure pilots are genuinely competent in attitude flying, stalls even spins, UP recoveries - and keep current 2-3 times a year minimum. That is an awful lot of aerobatic aircraft hire, and will kill a lot of pilots in accidents. It won't happen, and I suspect we will just continue to see a small number of LoC accidents... |
Deep stalls are not reserved for T tails only. I have trained deep stall in the 737 sim several times, both before and after AF 447. Deep stalls are way different than regular stall, and can take thousands of feet to recover from.
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https://pbs.twimg.com/media/B7TVMfLCUAApZHL.jpg:large
https://pbs.twimg.com/media/B7TU-uGCIAA0EMq.jpg:large https://pbs.twimg.com/media/B7TT7dBCcAAjVIz.jpg:large According to Twitter: Singapore vessel MV Swift Rescue locates fuselage |
Singapore vessel MV Swift is saying it has located the fuselage of QZ 8501. An ROV has been sent down to photograph fuselage plus wings. (Jackson Board for Channel News Asia who seems to be fairly on the ball with this.)
Edit: a good job as conditions in the crash area are difficult today. |
Volume is correct about the inability of flight simulators to accurately replicate the real aircraft's post stall behaviour. Test pilots do not take commercial aircraft that far into the stall regime, and certainly not at high altitudes, it is simply far too dangerous. Therefore all the models used in simulators for post stall behaviour are based on extrapolated data and wind tunnel experiments.
Pilots should not assume that what they see in the simulator post stall is correct. In fact it is positively dangerous to do so. I would be very interested to hear from 'those in the know' what the industry is doing about the conclusions of the work done by the IPTC. Why are the regulators dragging their heels over requiring improved training? Are airlines implementing the recommended improvements despite a lack of response by the regulators? See:- ANALYSIS: Modernising global airline pilot training - 1/12/2015 - Flight Global |
Second picture above appears most telling - consistently with the tail section of the wreckage, the left side of the fuselage appears to be torn away midway along.
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Originally Posted by Volume
It is not required to fly full stalls in flight testing.
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I cannot believe the uniformed nonsense being posted in respect of transport category aircraft stall testing, stall characteristics and what is required to demonstrate compliance with the certification standards.
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no need to kill a lot of pilots to teach basics
NigelOnDraft: Sorry , but -- without debating the cost & headaches of teaching people how to really fly -- I find the conclusion that this "will kill a lot of pilots" unjustified. In more than 20 years of teaching advanced aerobatics, as well as stalls/spin and unusual attitudes (including, for a time, dozens and dozens of Ab Initio China & Gulf Airline students) I, and my then colleagues, did not have a single aerobatic accident. Pray tell why this should change.
"The solution, if we wish to reduce LoC accidents (which are very rare), is to ensure pilots are genuinely competent in attitude flying, stalls even spins, UP recoveries - and keep current 2-3 times a year minimum. That is an awful lot of aerobatic aircraft hire, and will kill a lot of pilots in accidents. It won't happen, and I suspect we will just continue to see a small number of LoC accidents... |
From the photos of the wing, it looks as though the flaps have been extended?
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@zzuf
I cannot believe the uniformed nonsense being posted in respect of transport category aircraft stall testing, stall characteristics and what is required to demonstrate compliance with the certification standards. |
It looks more like the flaps have broken off. What you see are the spoilers.
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zzuf is right.
Most comments on stalling are by those who have never stalled a swept wing jet at high altitude except once or twice in a simulator and even then not in a massive Cb at night. Certification is not an absolute safety measure; merely a best practice, commercial option that meet statistical requirements. a |
Could the scorch marks in the photo on post 1970 be due to a lightning strike?
http://i.telegraph.co.uk/multimedia/...e_3163123b.jpg |
Owain,
JT will also confirm that I was CTP for a regulatory authority. As this is about A320 I must add that I spent plenty of time with the late Nick Warner during various evaluations including stalling. Cheers |
Blimey that is a far more intact fuselage than I was expecting. Does look like a scorch mark on the tail section....
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Does anyone know what is the speed of response time of the THS ?
Mechanically it is adjusted by a Jackscrew that is wound in or out by motors... Looking at a previous FDR graph of a/p control input, to actual movement, it seems as if it takes in the order of 15 seconds to travel. In other words the elevator control is not as responsive as on an aerobatic airplane. |
The scorch marks were not present in earlier images therefore can one assume they are part of the dismantling process?
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It looks like someone has taken a welding torch to it. One wonders also what exactly the guy with the huge crowbar is hoping to achieve.
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Scorch mark on the tail section....
No sir, the Engineer is cutting it up with an angle grinder. See previous picture... https://pbs.twimg.com/media/B7Exxw6IQAIelwy.jpg:large |
Originally Posted by zzuf
JT will also confirm that I was CTP for a regulatory authority. As this is about A320 I must add that I spent plenty of time with the late Nick Warner during various evaluations including stalling.
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