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Air France 447

Old 06-03-2009, 07:57 PM
  #181  
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Several of the articles I have read have quoted supposed experts here and there as saying that weather or lightening is not likely to have played a factor. I think that, until the wreckage is recovered to show otherwise, they are not being honest.

Going with probabilities here, I'd say that odds are against a sudden explosive event based on the wide debris field. All of this is just a discussion of the most probable occurrence as no facts are known, yet.

Debris fields were reported to be separated by as much as 140 miles. Part of that can be explained by a difference in the way individual pieces of debris are affected by the wind (i.e. high floating light material is more likely to be blown along by the wind than low-floating heavier debris that is more likely to be influenced by the water currents). The scattering of debris by the forces inside of a thunderstorm could also be a factor, but probably not over an area 140nm wide. The biggest influence; however, is where the individual pieces hit the water. With as much as 50 to 140 miles between the pieces, the highest probability is likely to be that parts of the aircraft separated in flight and the aircraft continued for a while before the final crash. That would mean that the aircraft structure disintegrated over a period of time. The recent history of bombs or explosive events (TWA 800 and Pan Am 103) resulted in scattered debris fields, but their debris fields had a much smaller footprint than 50 to 140 miles across - or they didn't result in crashes at all because they were not powerful enough (PAL 434 in 1994).

The biggest clues will be if they find individual flight control surfaces separated by miles from the wreckage and if large chunks of fuselage were missing from the wreckage along with the missing flight control surfaces. For example, if I were investigating, I'd be interested in whether or not the vertical stab is located with the rest of the fuselage wreckage. That scenario would be similar to the Air Japan B-747 that lost its vertical stab due to an improper repair of the aft pressure bulkhead - it continued to fly for 32 minutes. A B-52 that lost its vertical stab (or at least most of it) flew on and continued to a safe landing. Of course, the 2001 Airbus that lost its vertical stab crashed immediately afterward - so there is a wide latitude of how far an aircraft may fly with no vert stab. The same can go for most any flight control surface based on how much is lost and what it takes with it. Such failures are not unheard of - the MD-11 elevator counter-weights have been known to destroy the elevators in severe buffeting conditions due to the twisting moments caused by the inertia of the weights themselves against the rest of the elevator which is being held static by the hydraulic actuators.

Stresses may have been so severe that the separation of parts of the aircraft could have resulted in breaches to the structural integrity of the cabin and/or cargo compartments. In that case, the majority of the aircraft would continue along a trajectory while debris from within the aircraft could be spread across a wide area. That scenario would be similar to the Aloha 737 mishap. Depending on how the structure was breached, the loss of several components (hydraulics, electrics, etc) would be possible if not probable and the damage could be so severe that even fail-safe systems could be eliminated and cause an eventual loss of control or continued flight in turbulent conditions could result in the eventual complete destruction of the aircraft.

Given the wide variety of scenarios that are plausible, they need to focus on getting more facts for now. No matter what the investigation finds, it is way too early for any of these manufacturer or industry reps to be talking about what "did not" happen. Talk such as that is nothing more than misleading at best, negligent at worst.

P.S. - for you current T-38 drivers out there, it reminds of the quote that came out within a day or so after the KCBM mishap as flying resumed - "we are confident that this mishap was not maintenance related" or something similar. OH REALLY!

Last edited by LivingInMEM; 06-03-2009 at 08:44 PM.
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Old 06-04-2009, 05:37 AM
  #182  
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http://www.telegraph.co.uk/news/worl...ht-AF-447.html
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Old 06-04-2009, 06:23 AM
  #183  
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The AF C-17 has a turbulence mode that commands the autopilot to hold a pitch and not chase an altitude and the auto-throttles hold their position and do not chase an airspeed. The older Boeing 757/767s do not have this feature. Any bus drivers care to tell of their turbulence features/procedures?
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Old 06-04-2009, 08:03 AM
  #184  
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Originally Posted by Toejam View Post
The AF C-17 has a turbulence mode that commands the autopilot to hold a pitch and not chase an altitude and the auto-throttles hold their position and do not chase an airspeed. The older Boeing 757/767s do not have this feature. Any bus drivers care to tell of their turbulence features/procedures?
Turbulence damping is provided automatically in Normal Flight Law. The flight computer adds commands to elevator and yaw damper unit to null out structural modes induced by turbulence. Operates when a/c is above 200 kts, autopilot is engaged and aircraft within the normal flight envelope.

There is no TURB button (pitch hold) on an A330 like there was on the 747 and DC-10.

Last edited by Nosmo King; 06-04-2009 at 08:17 AM.
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Old 06-04-2009, 10:07 AM
  #185  
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Originally Posted by TurnAndBurn View Post
From avherald.com

The sequence of messages reportedly received via ACARS raises memories of the Accident: Qantas A333 near Learmonth on Oct 7th 2008, sudden inflight upset injures 74 people on board and Incident: Qantas A333 near Perth on Dec 27th 2008, navigation system problem, and turns attention towards the emergency airworthiness directive released by both FAA and EASA, see also EASA issues updated emergency directive regarding Airbus A330 and A340 ADIRU issues."
Having deep ties to Boeing, as an engineer, and former employee, I can say this "if it's not Boeing's I'm not going!" Fire away.
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Old 06-04-2009, 10:56 AM
  #186  
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Originally Posted by 577nitro View Post
Having deep ties to Boeing ...
Apparently, not so deep.

And obviously, you missed the memo while you were here. Don't throw stones in a glass house.

You're on your own with your comments. Those who take pride in their work respect their competition

....and in difficult times, mourn with them as well.

Last edited by 11Fan; 06-04-2009 at 11:10 AM. Reason: afterthought
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Old 06-04-2009, 10:59 AM
  #187  
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IIRC, the same thing that happened to the A330s over Austrailia happened to a 777 as well.
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Old 06-04-2009, 11:28 AM
  #188  
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Originally Posted by 80ktsClamp View Post
IIRC, the same thing that happened to the A330s over Austrailia happened to a 777 as well.
It did, thats why there was also an Emergency AD issued for the 777.

I will say that from an engineering standpoint, composites scare the hell out of me...

Have you ever seen a sailboat mast snap? Do you think there are ways to detect an impending composite failure like there are with aluminum and other alloyed metals?

That is one of my big worries about the newer aircraft being manufactured by both Boeing and Airbus. Every succeeding design keeps using more composites in structurally critical areas.

Maybe the saying should be modified to "If it ain't an OLD Boeing, I'm not going.:
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Old 06-04-2009, 11:39 AM
  #189  
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Originally Posted by Nosmo King View Post
It did, thats why there was also an Emergency AD issued for the 777.

I will say that from an engineering standpoint, composites scare the hell out of me...

Have you ever seen a sailboat mast snap? Do you think there are ways to detect an impending composite failure like there are with aluminum and other alloyed metals?

That is one of my big worries about the newer aircraft being manufactured by both Boeing and Airbus. Every succeeding design keeps using more composites in structurally critical areas.

Maybe the saying should be modified to "If it ain't an OLD Boeing, I'm not going.:
Scary. For all of our sakes lets hope you are wrong, but I have the same fears!


<== ACL65 not bidding a composite jet like the 350 or 787 anytime soon!
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Old 06-04-2009, 12:00 PM
  #190  
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Latest information just put out on CNBC at 1554 this afternoon has it that "excessive speed" appears might be a problem with the new air buses and could have been a contributing factor in the accident. Said that a safety bulletin is going to be put out limiting their "cruising speed". Interesting................
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