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AF447

Old 16th Sep 2009, 22:32
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A possible starting point could be to replace the on-board FDR and CVR systems with real time data transmissions. If ACARS cannot cope/is too expensive to handle the volume of data or cannot deliver the required dependability, the Iridium system (Iridium) would seem to be an alternative. If such a data collection service were to be made available, automatic monitoring would be possible
Bad idea.
Augment perhaps, enhance -sure! but replace? never!

Instead of an independent device with its encapsulated nugget of information, you have a parsed 'summarized' data stream subject to the control of....who?
The Airline? the Airbus/Boeng? or the NTSB/CAA body?

The scheme does have some attractive parts to it, a central database of all flight parameters that can be data mined and analysed....nice!
but dont forget, these tools are for POST MORTEM not protection.

"Sir, why are you wearing a LEAD LIFE JACKET?"
"why, so if I DROWN, my body is not swept away by the current!"

A more frequent pinging of flight position and altitude (with maybe more frequent updates triggered by any anomalies) AND A QUICKER RESPONSE WHEN CONTACT IS LOST should more than suffice and would be a very minor software update to the ACARS system and its ilk
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Old 17th Sep 2009, 00:23
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Press Coverage

Some recent coverage....

Pilots question airspeed sensors' troubled history - Yahoo! News
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Old 17th Sep 2009, 00:27
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whats curious to me is why in heaven's name the Autopsy reports havent been released.
In addition to a general summary types of injuries sustained, there is one such report that may bear strongly on this accident. It is a bit grim, but bodies can convey witness marks from objects in the vicinity. The whereabouts of the Captain on the aircraft at the time of the accident might be pinned down conclusively by paint fragments, plastic fragments, or the general shape of his injuries corresponding to items known to be in a particular location in the aircraft. I hope someone has looked at this aspect of nailing down who was in the cockpit. With an accident like this, there is no certainty of finding the Boxes within a relevant time frame.
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Old 17th Sep 2009, 13:04
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Please explain to this SLF the normal recovery from a flat spin

Hello,

I know this is all based in conjecture as to what the causal factors were which brought down AF447. Many posts ago some were entertaining the idea of a flat spin brought on by....whatever. (weather-related? Perhaps. Perhaps not.)
My question to all you pilots out there is this. What are the "normal" recovery methods used to fly an aircraft out of a flat spin? Are there any? Is this scenario something which is not simulate-able in the simulator?
These questions are asked merely out of curiosity and to obtain knowledge. In no way am I inferring anything.
Thank you.
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Old 17th Sep 2009, 15:26
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Instead of an independent device with its encapsulated nugget of information, you have a parsed 'summarized' data stream subject to the control of....who? The Airline? the Airbus/Boeng? or the NTSB/CAA body?
The whole idea is a nonstarter given the resistance by pilots and their unions to the FDRs being read/analyzed in the course of routine operations.

I am not holding my breath for the recorders. I feel that those in the know already have a pretty clear picture of what happened and why and hopefully are acting on it. For the rest of us - the investigation will drag on and on until some appropriately anodyne language is found that all parties can live with.
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Old 17th Sep 2009, 15:51
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Please explain to this SLF the normal recovery from a flat spin
An A330 is not a Pitts or an Extra 300. There are recovery techniques but for Aerobatic aircraft and aerobatic (well ) trained pilots, not for airliners.

Even one of the best pilot still around , i.e. Chuck Yeager, did eject after a flat spin in the F104 prototype I my memory serves me well.
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Old 17th Sep 2009, 16:07
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@ATC Watcher:

Then is it correct for me to ascertain that a flat spin is an unrecoverable condition in
a commercial aircraft?
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Old 17th Sep 2009, 16:37
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If the GofG is far enough aft to generate a 'flat spin', it tends to be difficult to recover in ANY aircraft unless spin recovery devices are fitted. However, it should be remembered that we have absolutely NO proof that 447 entered any sort of spin.
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Old 17th Sep 2009, 16:53
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BOAC:

I never alluded to the flat spin being the cause of AF447. (My use of the word "conjecture" shows that.) My post says as much. I know this topic was broached in previous postings but I was just inquiring about recovery techniques from such a condition as I don't recall having seen anything about such techniques.
Thank you.
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Old 17th Sep 2009, 17:25
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One well documented high altitude stall and flat spin
airliner accident was this one:

ASN Aircraft accident Tupolev 154M RA-85185 Donetsk

Pulkovo Tupolev 154M

The accident circumstances, weather was similar to AF447.

For them flat spin was unrecoverable.
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Old 18th Sep 2009, 03:57
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Flat Spin Recovery?

Deploy the spin chute. Don't have one? Well, there are a few things you can try with the engines to break the spin but they've probably all flamed out or are stalling due to the inlet conditions in a flat spin. So recovery is very unlikely. However, my understanding is that they hit the water nose high and wings level with a high sink rate and minimal yaw. That suggests an upset into a high-speed spiral dive with a recovery in progress when they ran out of altitude, rather than a flat spin which would result in a completely different water entry.
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Old 18th Sep 2009, 04:00
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Arguably one of the very best aero pilots ever, Art Scholl, was killed while flying and filming the Movie, "Top Gun". From memory, I think he was flying an Extra 300, but I think his favorite had been the Chipmunk. He entered a flat inverted spin and went into the Ocean with his a/c. The spin entry was planned, and needless to say, all were astonished when he failed to recover. When spin testing a/c, a drag chute is fitted to recover controlled flight if the control surfaces cannot. IMO it is safe to say 447 would have had an enormous challenge to 'merely' ditch, let alone recover from upset, given flight conditions. There is NO reason to believe the crew were anything less than heroic.

Will
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Old 18th Sep 2009, 11:29
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T-Tail

Ptkay:

but Tupolev 154M is T-Tail and this makes a HUGE difference

Yiorgos
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Old 18th Sep 2009, 15:00
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Flat Spin Recovery?
......... However, my understanding is that they hit the water nose high and wings level with a high sink rate and minimal yaw. That suggests an upset into a high-speed spiral dive with a recovery in progress when they ran out of altitude, rather than a flat spin which would result in a completely different water entry.
It appears that AF447 came down rapidly, but how did it dissipate all that energy in perhaps 5-8 minutes and then impact at relatively low airspeed and high angle of attack? To me it suggests they were locked in a stable deep stall and couldn't break it. Swept wing aircraft do pitch up in a deep stall and that can completely overpower the tail's corrective abilities. An aft CG makes it worse. With airliners, particularly FBW ones you just are not supposed to get in a deep stall in the first place.
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Old 18th Sep 2009, 17:48
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Arguably one of the very best aero pilots ever, Art Scholl, was killed while flying and filming the Movie, "Top Gun". From memory, I think he was flying an Extra 300...
Just to set the record straight - Scholl's aircraft was a Pitts S-2A
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Old 18th Sep 2009, 19:50
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Flat spins and obsession

Flat spins seem to be a nice boogey man again, with some people seeming to insist that was the mechanism behind the AF447 demise.

I cannot naysay that they're incredibly dangerous events. I can observe that in a nice flat spin the plane's not "going anywhere." (I parenthetically note that that nice big flag in the air called a vertical stabilizer isn't going away, either, given the parameters for its removal from AF447 by a forward push rather than a sideways push. That means the spin would have to be a seriously slow spin.)

What I can observe is mm43's excellent work, again. (And if needed again and again.)

Look at the last reported position. Look at the ACARS messages. How does a flat spin account for the potential impact locations as derived by mm43's many efforts including but not limited to Crash Location - A revisit using OSCAR & Quikscat data and Bathymetry - centered on 3N 31W?

When you can reconcile these inconvenient facts with a flat spin scenario and why the plane got to those potential impact points and THEN chose to flat spin I'll entertain that scenario for AF447. Until then it appears to be vaporous wanderings of a group of people bored out of their minds with this discussion.

Maybe another topic would be a good place to vamp on "flat spin" conditions, their dangers, recovery therefrom, and aircraft parameters that seem to foster or prevent flat spins.

JD-EE {o.o} Just sayin'

Last edited by JD-EE; 18th Sep 2009 at 19:51. Reason: and - note I said "seeming" on that first line....
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Old 19th Sep 2009, 12:56
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Please explain to this SLF the normal recovery from a flat spin

Please explain to this SLF the normal recovery from a flat spin
1 - Idle power;
2 - Hands OFF the stick/yoke;
3 - Full Rudder deflection, opposite to the rotation of the Spin, until rotation stops;
4 - Neutralize Rudder and pull out of the dive.

Now, this is the Muller/Beggs technique. Used on aerobatic (normally single-engined) aircraft.

An airliner is not supposed to be designed to be flown into a spin, nor (as far as I know) is supposed to be certified to fly-in and fly-off a spin. There is, therefore, no "technique" or training required by crews to fly-off spins on any Airbus or Boeing a/c.
Airline Pilots are supposed to prevent their aircraft to enter any stall. They are supposed to be aware at all times and to manage the energy of their aircraft to avoid them to enter any unrecoverable situation. But the issue you are rising is much more complex than that...and an A330 with at least 3 Tons of Fuel on the Trim Tank, with an aft CG is hardly "spin recoverable".
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Old 19th Sep 2009, 13:56
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Airline Pilots are supposed to prevent their aircraft to enter any stall. They are supposed to be aware at all times and to manage the energy of their aircraft to avoid them to enter any unrecoverable situation
If you could see what I am sure hundreds of simulator instructors often see during their training career, you would be staggered at the number of experienced and not so experienced pilots that are "supposed" to be able to prevent their aircraft from entering a stall - but are unable to do so.
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Old 19th Sep 2009, 15:07
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last resort--

re: the question about recovery from flat spin--

with my limited knowledge, if i find myself strapped to an aircraft that appears to have a mind of its own and everything else i have tried doesn't work, i will put the gear down.

that might put enough drag into the equation to break the stalemate.

i read that the pilot of an uncontrollable 727 at altitude had tried everything else he knew (he was an aerobatic pilot); put the gear down as a last resort. the china 747 experienced such g-forces that the uplocks failed and the gear came down and they both lived to tell the tale.

admittedly not related to the thread's title.

and will respect any feedback.
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Old 19th Sep 2009, 16:18
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The Energy Wasn't Dissipated

"It appears that AF447 came down rapidly, but how did it dissipate all that energy in perhaps 5-8 minutes and then impact at relatively low airspeed and high angle of attack?"

That's the problem. With enough elevator control power and no computer between you and it to restrict G, you can yank the nose up without changing the velocity vector much at first. The pitot won't read much airspeed because it's looking forward and not down, but you're still going down at almost the same rate of descent, which is consistent with a high angle of attack.

Last edited by Tailspin Turtle; 19th Sep 2009 at 16:31.
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