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-   -   Air Asia Indonesia Lost Contact from Surabaya to Singapore (https://www.pprune.org/rumours-news/553569-air-asia-indonesia-lost-contact-surabaya-singapore.html)

woora to ypph 13th Jan 2015 23:31

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

oblivia 13th Jan 2015 23:45

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.

Ian W 14th Jan 2015 00:03


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.

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.

Ian W 14th Jan 2015 00:19


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.

The major problem in aviation is that often the people paying are not the ones that benefit. So if the AT Service provider upgrades its equipment at a cost, the airlines benefit not the ATSP. If the airlines equip with ADS then the ATSP need not maintain heavy primary radar, the aircraft see little benefit unless the airspace concepts of operations are changed.

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.

ACLS65 14th Jan 2015 01:22


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.
Earned a bookmark for the next time we get weather here. Another promising option would be space based RADAR eliminating the need for additional RADAR equipment on the planes.

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.

onetrack 14th Jan 2015 02:10


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.
That's an excessively simplistic and inaccurate explanation of what has happened in many recent aircraft crashes. Yes, there have been some glaring piloting skill deficiencies exposed, but to reduce them to your description is not correct.
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.

A0283 14th Jan 2015 02:17

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.
During the design process you also have budgets of weight. You start with cutting kilo's and end with trying to cut grams. Just another type of beans :-). Designers have to irk quite a lot before they get it right :-).


really, not exactly proactive forward thinking govt.
You can operate pro-actively and count beans at the same time. To survive in business you need to do both. Reminds me of Sir John Harvey-Jones... he would have loved talking to you.


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 is hard to design and manufacture aircraft out in the open :-). Engineers can be quite jealous of pilots :-). That's why quite a few fly outside office hours.


... it could have been many years for the full facts of metal fatigue's random scatter to be fully accounted for in design.
There was quite a lot of knowledge on metal fatique already. Alas, in ship design. You can take a look at Liberty ship hatch design and compare that to Comet window design. Interesting parallels, and of course also a number of differences (thin vs fat plate, riveting vs welding(funny the Liberties were an early change from riveting into welding)).

peekay4 14th Jan 2015 03:17

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.

WSSS 14th Jan 2015 04:02

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?

glendalegoon 14th Jan 2015 04:43

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.

ekw 14th Jan 2015 05:11

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.

oblivia 14th Jan 2015 05:13

@Ian W


The accountants (aka beancounters) will then look around for savings and an easy area is training.
Regulators create the standards (including for training). If pilots or airlines fail to meet those standards and don't face sanctions for such breaches, well... I blame the regulators (and, ultimately, the political climate that equates free markets with unregulated markets).

Gretchenfrage 14th Jan 2015 05:21


Unstalling a wing is very simple, decrease the AOA to less than the stall AOA.
How right you are! But .......

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.

Capn Bloggs 14th Jan 2015 05:27


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.
elevator deflection with full nose up on the stab may not be sufficient to move the AOA, you mean... :cool:

bloom 14th Jan 2015 05:30

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.

Blake777 14th Jan 2015 05:45

Cabin positions of victims recovered thus far:

https://mobile.twitter.com/TheNewOce...904448/photo/1

DrPhillipa 14th Jan 2015 06:00


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.
So you were trained for stall recovery in the sim? Who put your aircraft into the stalls required, and recovered from them, to provide the data for 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?

AmuDarya 14th Jan 2015 06:05

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

Volume 14th Jan 2015 06:53


If not push, just release the backpressure

I truly doubt that FBW had anything to do with this incident
As most modern FBW aircraft do also have some sort of auto trim logic in their control system, there is no more backpressure. You really have to push to tell the computers that you want to go back to the condition you were in before you pulled. You can release the backpressure and your control system still remembers your pull command and delivers what you asked for.
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.
I would not trust the sim in those situations anyway, it is far outside the range it has been developed for. For most aircraft the numbers in the sim computers will simply be extrapolated, and not resulting from flight test data.

they prefer to train to avoid the stalls in the first place.
It does however not do any harm to also train how to recover from it. First priority should of course always be avoidance. Just like CBs, terrain, traffic...
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.

NigelOnDraft 14th Jan 2015 08:52

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...

ManaAdaSystem 14th Jan 2015 08:56

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.

Dopsonj 14th Jan 2015 09:03

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

Blake777 14th Jan 2015 09:03

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.

Bergerie1 14th Jan 2015 09:03

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

Blake777 14th Jan 2015 09:29

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.

Gysbreght 14th Jan 2015 09:34


Originally Posted by Volume
It is not required to fly full stalls in flight testing.

It depends on what you mean by "full stall". The regulation calls for the speed to be reduced until the stall is identified, and lists the criteria that represent acceptable stall identifications. Recovery is started as soon as the stall is identified, i.e. it is not required to investigate 'deep' penetrations into the stall regime.

zzuf 14th Jan 2015 09:44

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.

formationdriver 14th Jan 2015 09:51

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...

training wheels 14th Jan 2015 10:12

From the photos of the wing, it looks as though the flaps have been extended?

Owain Glyndwr 14th Jan 2015 10:13

@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.
I take it you meant "uninformed nonsense", in which case I would simply say that Gysbreght is better informed than most posters here on certification as John T may well confirm.

procede 14th Jan 2015 10:15

It looks more like the flaps have broken off. What you see are the spoilers.

RifRaf3 14th Jan 2015 10:18

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

Kerwin 14th Jan 2015 10:27

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

zzuf 14th Jan 2015 10:30

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

LadyL2013 14th Jan 2015 10:32

Blimey that is a far more intact fuselage than I was expecting. Does look like a scorch mark on the tail section....

phiggsbroadband 14th Jan 2015 10:38

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.

susier 14th Jan 2015 10:47

The scorch marks were not present in earlier images therefore can one assume they are part of the dismantling process?

DrPhillipa 14th Jan 2015 10:48

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.

phiggsbroadband 14th Jan 2015 10:50

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

Gysbreght 14th Jan 2015 11:05


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.

I take it you were not referring to my post. Otherwise please indicate what you disagree with.


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