Hi Gums,
Originally Posted by gums
The wreckage data ( distribution) we already have has a wealth of data that will be combined with the recorded parameters, IMHO. So we should get a very good replay of impact.
Right, we'll certainly know everything if the recorders are fully readable.
Originally Posted by gums
The big question is how in the hell the plane got there, ya think?
As far as the horizontal distance versus vertical distance goes, it is not betond my personal experience. As a light plane pilot previously recalled, if the plane is in a fully-developed stall, it can descend at a great rate without much forward velocity. In my own experience, one jet I flew had exceptional directional control in a full stall ( rudder versus aileron for maintaining a heading and picking up the low wing). Just release back pressure and it came right out. I could descend at 10,000 feet per minute or more ( the vertical velocity meter was pegged) with an indicated speed of about 60 knots. So I could go one mile and lose 10,000 feet or so.
We already tried to put some numbers together in the previous thread around this stage:
http://www.pprune.org/tech-log/39510...ml#post6356297
My point was that it looks not likely that an early loss of control (0210-0210:20) happened to AF447 based on those published data I'll repost below.
From nine cases studied, we'll find an altitude loss in the range between 12,000 and 32,000 feet per minute, and a ground covered distance range between 3 to 17 Nautical Miles, while no event lasted more than 210 seconds overall after the LOC event:
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9 unrecovered upsets from cruise level (data Metron Inc., BEA study):
Date.........ft/mn..Level..Dur....Dist..Type....-> Cause
07.12.1995..32,000..FL310...57s...8 NM..TU-154B -> Spiral / roll upset
19.12.1997..29,000..FL350...75s...5 NM..B-737.. -> Unknown
21.12.2002..27,000..FL180...40s...2 NM..ATR 72. -> Stall / icing
19.11.2001..26,000..FL260...59s...4 NM..IL-18V. -> Spiral / diving
01.01.2007..20,000..FL350..105s...9 NM..B-737.. -> Roll upset
15.07.2009..16,000..FL240...90s...5 NM..TU-154M -> Spiral / roll upset
22.08.2006..14,000..FL390..166s...3 NM..TU-154M -> Stall-spin
23.03.1994..12,000..FL310..156s...3 NM..A-310.. -> Spiral-spin / roll upset
16.08.2005..12,000..FL310..210s..17 NM..MD-82.. -> Stall
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AF447 - timed cases for one upset from cruise level:
01.06.2009..35,000..FL350...60s..~5 NM..A-330 (1 mn)
01.06.2009..23,000..FL350...90s..~5 NM..A-330 (1.5 mn)
01.06.2009..17,500..FL350..120s..~5 NM..A-330 (2 mn)
01.06.2009..12,000..FL350..180s..~5 NM..A-330 (3 mn)
01.06.2009...9,000..FL350..240s..~5 NM..A-330 (4 mn)
01.06.2009...7,000..FL350..300s..~5 NM..A-330 (5 mn)
01.06.2009...6,000..FL350..360s..~5 NM..A-330 (6 mn)
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1 Recovered upset: B747 China Airlines (17.02.1985)
1. 1014:50 -> 40,442 ft -> roll upset (4.8 G pull up)
2. 1015:23 -> 30,132 ft -> unreliable attitude data (5.1 G pull up)
3. 1017:15 -> 9,577 ft -> recovery & climb
Total upset duration: 145 sec.
1..10,310 ft lost...33 sec..18,700 ft/mn
2..21,155 ft lost..112 sec..11,300 ft/mn
3..31,465 ft lost..145 sec..13,000 ft/mn (average)
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"Upset" definition (from “2008 - Airplane Upset Recovery Training Aid Revision 2”):
An airplane upset is defined as an airplane in flight unintentionally exceeding the parameters normally experienced in line operations or training. In other words, the airplane is not doing what it was commanded to do and is approaching unsafe parameters.
While specific values may vary among airplane models, the following unintentional conditions generally describe an airplane upset:
• Pitch attitude greater than 25 deg, nose up.
• Pitch attitude greater than 10 deg, nose down.
• Bank angle greater than 45 deg.
• Within the above parameters, but flying at airspeeds inappropriate for the conditions.