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-   -   AF447 wreckage found (https://www.pprune.org/tech-log/447730-af447-wreckage-found.html)

EMIT 8th July 2011 03:12

CRAP or CREPE??
 
Well DC-ATE, as you can read in the BEA preliminary report, the airplane reacted in a totally normal way, as soon as a proper stick input was given: when the stick was pushed forward, the pitch attitude lowered and the AOA decreased.
Unfortunately the proper stick input was not maintained long enough to effect complete recovery from the stalled situation.
Nothing really crappy about aircraft response there, Fly By Wire or not.
"Even" an Airbus is a totally normal airplane if you treat it as such.

Do not get confused by Airbus being FBW, it is not statically unstable as an F-16 is. I am not gonna explain that further, that has been done very well by old Gums a lot of postings ago already.

before landing check list 8th July 2011 03:36

They even have "FBW" instead of throttle linkages on some race motorcycles. Why you may ask? So they can eek out a few less milliseconds on the throttle response time. EMIT, I agree if the aircraft did everything the pilots asked of it and if the pilots were not asking the correct questions then shame on them. However I still do not fully appreciate the fact that in essence every time you try to make a input you are asking a computer permission and depending on it's programming you may or may not get what you are asking for. Granted you do have to make the correct inputs, that is where YOUR experience comes into play. It is up to you as the pilot what kind of experience you can bring to the table and what kind of experience the bean counters are willing to pay for. Now we are back to front wheel drive cars made for mediocre driving skills.

Personally I do not mind FBW at all as long as it (the wire) is going through a control tube

I did have the opportunity of jump seating on a A320 (when you could do such a thing) and when we were at FL I asked what would happen if we lost all electrics, I mean ALL. I got a look like I was a kid asking what if a wing fell off. After a bit the captain said something about the FO opening a door to the RAT and then they would spend the rest of the fuel load trying to get a computer on line so they could land it. Yes, it is not unstable like a F16 (Neither is a dart or an arrow) but really what is the real purpose of FBW? I mean we have had fully coupled auto pilots for quite a while and they operated servos and worked just fine. Are we really saving a bit of weight so we can get another 10 passengers on board? Are we trying to reduce response time of a few milliseconds? They are even doing this to freakin helicopters, why? I do not think the benefits out weigh the negatives, but this is just me.

Do you want to be a board member so if the company fails the blame can be passed around or do you want to be a pilot where you(the crew) are fully responsible for the outcome of the flight?

Maybe I am getting old.

RWA 8th July 2011 04:32

Quoting EMIT:-


Well DC-ATE, as you can read in the BEA preliminary report, the airplane reacted in a totally normal way, as soon as a proper stick input was given: when the stick was pushed forward, the pitch attitude lowered and the AOA decreased.

Unfortunately the proper stick input was not maintained long enough to effect complete recovery from the stalled situation.

Unfortunately, EMIT, you appear to be assuming something the BEA's (increasingly suspect) note does not say. In fact, it only states:-



"At 2 h 12 min 02, the PF said "I don’t have any more indications", and the PNF said "we have no valid indications". At that moment, the thrust levers were in the IDLE detent and the engines’ N1’s were at 55%. Around fifteen seconds later, the PF made pitch-down inputs. In the following moments, the angle of attack decreased, the speeds became valid again and the stall warning sounded again."

So there is no evidence that the PF did not in fact maintain the nosedown inputs?

Typically of the BEA (on this occasion) the note later mentions both pilots applying simultaneous inputs - but it doesn't indicate whether those inputs were up or down......

On the other hand, the BEA DOES say without equivocation that the THS remained in the same 'full up' position that it had adopted (for whatever reason) at the onset of the accident "until the end of the flight." And, as the BEA said in the earlier Perpignan report which I quoted above, this would likely have left the pilots in a situation which they "could not manage to counter, even with the sidestick at the nose-down stop"?

jcjeant 8th July 2011 05:56

Hi,


Typically of the BEA (on this occasion) the note later mentions both pilots applying simultaneous inputs - but it doesn't indicate whether those inputs were up or down......
This one of the reason why I posted in the thread in Tech Log:
The BEA communicate .. but not inform .. just like a tabloid
Too much people confuse the words communication and information .. they are two different beasts ...

fizz57 8th July 2011 07:11

Guys, my guess is that the BEA report is deliberately incomplete to hold off the inevitable lawsuits to the proper time, ie. after the final report is published. In my view, it says all that needs to be said, without actually giving anything definite the lawyers can grasp on. Unfortunately it also leaves enough holes for those on this forum who of course know exactly what actually happened to try and squeeze their pet theories into the gaps.

I'd say the "how" , even if not the "why", is clear enough, and the real professionals (should that be singular?) who have contributed to this topic have it about right.

BOAC 8th July 2011 07:43


Originally Posted by fizz
I'd say the "how" , even if not the "why", is clear enough

- we would all be interested to know exactly what happened - since you obviously do, can you tell us? It would save an awful lot of bandwidth (or should that be a lot of awful bandwidth...?)

RWA 8th July 2011 14:16

Quoting fizz57:-


Guys, my guess is that the BEA report is deliberately incomplete to hold off the inevitable lawsuits to the proper time, ie. after the final report is published.
Sadly, I think you're pretty nearly right there, fizz57. Except that I suspect that the BEA's thinking was even more short-term than that - that they were just required to shove out something that 'hinted' at pilot error, to get Airbus 'off the hook' before the Paris Airshow.......


In my view, it says all that needs to be said, without actually giving anything definite the lawyers can grasp on.
Sadly, I have to disagree there. The BEA's job is to determine the cause(s) of the accident as soon as ever possible, so that similar accidents can be avoided in future. Maybe I'm an idealist dreaming of a 'perfect world' - but we are probably all agreed that the BEA's note is more notable for what it leaves out, rather than what it puts in. The BEA's job is not to 'play poker' with lawyers - however much pressure the political guys put on them.

In a word, it's one of the most 'unprofessional' documents I've ever read in my life.......

Quoting jcjeant:-


The BEA communicate .. but not inform .. just like a tabloid

Exactly right in my view.

OK - I'll stick my neck out with a couple of 'speculations'......

1. As to the stall warnings cutting in and out, my guess is that this had to do with the 'Indicated Airspeed' being understated due to icing and/or the steep pitch-up. As far as I know (though I very seldom flew anything that had any sort of stall warning) stall warnings are 'disabled' below a given airspeed - simply because, if they weren't, they'd go off during the landing flare.......

2. As to the behaviour of the THS, if I was involved, I'd look very closely at the question of whether, if the autopilot and autothrust 'sign off,' it is designed to 'fail safe' or not. After all, the normal 'duty' of the THS in automatic flight, again as far as I know, is to maintain a precise altitude. For all I know, the THS, both at Perpignan and in the AF447 accident, was simply going on with that 'normal job' - trying to regain the assigned altitude it had last been set to maintain, before the autopilot was switched off (Perpignan) or 'signed off' (AF447)?

To repeat, just 'speculations.' Constructive comments/further information/corrections welcome. But anyone who feels the need, by all means 'flame away' if that's your wont........

BOAC 8th July 2011 14:25

While waiting for the 'insight' from Fizz......................

1) Nothing really wrong with a stall warning 'going off' in a landing - if you land a C150 PROPERLY the stall warning should 'bleep' just as you touch. I agree it is not a nice thing to have on a commercial jet, however, it might frighten the pax.

2) Cannot agree with that para -THS is not 'dropped' with loss of A/P. It runs throughout the 'normal' flight regime in AB330 ie it does not 'fail',. A/P or manual. It is not there to maintain 'altitude' but to trim the tail to relieve elevator displacement (ideally!) to allow full elevator authority, just like any other trimmable tailplane.

Geragau 8th July 2011 19:53

Vel Paar's comment :

The company and the regulatory authorities take a dim view of anyone wanting to " improvise " to hone their basic manual flying skills!
bubbers44 :

VP, sorry you work for that company. If you don't use your initiative to hone your flying skills and go along with company logic you will lose your flying skills gradually. Hopefully you don't just settle into this job and accept it as the wave of the future. You can probably just do it anyway or if the company is a stickler for no handflying find a safer job.
Wow! bubbers, your grandpa must be the CEO of your airline! As far as I know, most air carriers want their pilots to utilise all the automation available to ensure smooth, economical and safe operations. I have unfortunate colleagues called up for tea and bickies when the AIMS/FOQA indicated some minor excursions when they flew manually without FDs.
A few indulgent chief pilots may just wave off such " no SOP " ops but they are getting fewer and fewer.

Phantom Driver 8th July 2011 20:12

Here we go again.....:(
(MHO..)

bubbers44 8th July 2011 22:40

G, so you are all in favor of no flying skills, just punch the buttons. Did you notice by chance what happened to AF447 using your technique? Sometimes the autopilot quits and it doesn't matter what button you push, you are just F*****.

bubbers44 8th July 2011 22:55

G, I am sure the UAE would have a hard time training a competent pilot so maybe button pushing a computer is your only option. I will be watching the news for the results. I'm sure something will be on in the near future.

xcitation 8th July 2011 23:20

Training
 
IMHO the question is "how do I practice flying outside the norm". The answer has to be using the simulator mostly. I can't really see how sail plane flying would help when the flight deck is lit up like a christmas tree, chirping and whooping, betty nagging and the ECAM scrolling by like the credits on a cheap movie. These pilots knew how to fly and recover from a stall. The big question is how did they process the PFD, ECAM, warnings... That kind of real/perceived multiple failure situation was never trained for. You can't get it in a sail plane or pitts.
The other issue is that you cannot go manual flying around coffin corner in chop. I question how much free play the earlier poster does at FL370 or above. Some manufacturers don't recommend manual at the cruise alt for particular types, its just too woolly to be playing buggles up there. As throwing out the SOPs and going full manual whenever he wants...:bored:

bubbers44 8th July 2011 23:42

BOAC, the thousands of hours spent in a Cessna 150 giving dual reminds me of the stall warning right at touch down. I would never want to hear it in an airliner. We were never exposed to that in airliners because it was well before stall. One time in 23,000 hrs I got a stick shaker in a 727 on a tight turn with speed brakes out at night going into Puerto Plata. I immediately stowed the speed brakes and landed normally. I appologized to my copilot even though he didn't care because it had never happened before or after in my career or his. Stowing the speedbrake fixed the problem because the speed was right, the speebrake brake caused the alert.

EMIT 8th July 2011 23:44

Exciting
 
xcitation, previous post

Flying manual, even at FL370 is NOT DANGEROUS, it is just NOT ALLOWED because it is RVSM airspace, where extremely accurate altitude keeping is required.

The 100 or 200 ft margin that we lazy, easily bored humans would maintain if we tried it for 9 hrs would be unacceptable for separation purposes. That is the reason why we delegate that task to ever sharp, never bored autopilots.

Glider flying would be a good training means to bring home the point that flying is a matter of maintaining attitudes and angles of attack, not something of text on screens, whether your IPhone or ECAM displays. Sure, those screens may convey important information, but the flying thing meanwhile is to keep the nose more or less near the horizon, with the blue sky on the side where your aircraft roof is.

FL370, or whatever level you are flying, should give ample margin for normal flying, if not, you have gone too high. Climbing towards, or starting a descent from level, is not against RVSM rules, by the way, neither is flying manually for a short time, e.g. to trim the aircraft properly.

TioPablo 9th July 2011 02:50


Glider flying would be a good training means to bring home the point that flying is a matter of maintaining attitudes and angles of attack, not something of text on screens, whether your IPhone or ECAM displays. Sure, those screens may convey important information, but the flying thing meanwhile is to keep the nose more or less near the horizon, with the blue sky on the side where your aircraft roof is.
:D Well said EMIT! (Goed gezegd!)

Geragau 9th July 2011 03:07


One time in 23,000 hrs I got a stick shaker in a 727 on a tight turn with speed brakes out at night going into Puerto Plata. I immediately stowed the speed brakes and landed normally.
Now how did that happen?

totempole 9th July 2011 03:33

I believe what all the self aggrandizing by the seats of their pants aces forget is that most shiny new jets fly out of and into airports where RNP/PRNAV requirements dictate use of the automatics. To fly manually on these SIDs and STARs is to invite possible deviations which can be " career stalling " for some.

Enough of all these great stories of heroics...the world is changing rapidly and like it or not the automatics will rule the future pilot's life. I love flying manually and I am lucky to have flights into airports where RNAV/PRNAV procedures are not required.

The challenge is to be totally proficient in correcting all the anomalies with the automatics entirely or partially. The supreme rule is never ever getting into situations where you have to use your super self declared " acy profiency " to manually get out of situations where you have gotten the automatics into. In my years of training pilots I have seen proud " old aces " get the automatics into !!!!ty situations and then proudly clicking them off to fly manually, mostly to an untidy end. Their pride.....they didn't crash despite the " failed automatics ". Actually there was absolutely nothing wrong with the automatics in those instances; the problem was the self declared aces did not understand the proper use of the automatics and misuse the functions.

This is not to say that pilots need not maintain their proficiency in flying manually. We have to strike a balance and the world is not going to change just to please those who think peddling the modern contraptions old fashion way is the be all and end all.

xcitation 9th July 2011 03:33

Manual flying above cruise alt
 
@ EMIT


Flying manual, even at FL370 is NOT DANGEROUS, it is just NOT ALLOWED because it is RVSM airspace, where extremely accurate altitude keeping is required.
Aren't you contradicting yourself?
Out of curiosity how much manual flying above cruise alt have you done and was it in chop?

A37575 9th July 2011 08:01


We have to strike a balance
Agree. But just what measurement of balance? Presumably you are talking about a balance between automatic pilot competency and pure flying skill competency. Surely a captain or copilot pilot licensed to fly a type of aircraft should have 100 percent competency on both skills. In your dreams is the reply from one cynic. If this is too optimistic then let's barter a little. Are you suggesting equal competency? Or is the balance 10 percent towards manual competency and 90 percent automatics competency?

Practice makes perfect and if the company policy is to stay on automatics from lift off to near touch down, then that only leaves the flight simulator for honing manual flying skills. Where simulator time is dictated by costs and company policy requires full use of automatics in the simulator, this leaves only a few minutes of effective time per session for the pilot to practice manually.

For example, there are many operators who regard simulator practice at unusual attitude recoveries in IMC as a total waste of time. Often the instructor hasn't got a clue how to instruct on these manoeuvres anyway. Which is one reason why there has been an increase in loss of control in IMC accidents in recent years.

Until authorities bite the bullet and insist more emphasis be placed on pure flying skills versus automatic pilot monitoring skills, the current trend towards loss of control in IMC will not reverse.


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