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Steve Fossett missing - Final NTSB Report

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Steve Fossett missing - Final NTSB Report

Old 13th Oct 2008, 06:50
  #201 (permalink)  
 
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I tried extended hands-off flying today. No spiral dive but the plane would often enter a very slow turn and be very stable with one wing slightly down. However it is extremely sensitive to rudder trim, not surprisingly, so it could have been due to not having this set absolutely perfectly.

(I flew a heli for the first time too, which was a lot of fun, but not really relevant!)

n5296s/n9888s
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Old 13th Oct 2008, 10:54
  #202 (permalink)  
 
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IO540

I have been thinking about this a bit more. The TB20 is, I think, designed as a long range tourer with IFR capability. It has no pretentions of aerobatic capability. As an older design it also does not gain its speed from clever aerofoil design or a particularly streamlined airframe - its more about brute strength. I would therefore have expected the designers to have built in a healthy quantity of stability both in pitch and roll. I wonder if there is any possibility the rigging is off, if yours displays so little stability in roll, or perhaps this is an unexpected quirk of the design?

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Old 13th Oct 2008, 11:21
  #203 (permalink)  
 
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I agree, the TB20 has a fine reputation as a long range cruising machine. The though of having to constantly 'fly' it seems a bit alien.
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Old 13th Oct 2008, 13:06
  #204 (permalink)  
 
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Since I was the person who introduced this whole roll stability thing into this thread, may I also be the one to suggest to stop discussing this now as part of the "Steve Fossett missing" thread?

If anyone feels the need to discuss the finer points of static, dynamic and divergent roll stability further, please open another thread.

(Alternatively, moderators, could you split off the last dozen or so posts into a different thread?)
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Old 13th Oct 2008, 17:06
  #205 (permalink)  
 
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Backpacker - agreed!

Fuji - I think that either somebody (not you) is taking the p*ss out of me as usual, or we are talking with wires crossed.

I have flown PA38, C150, C152, C172, C182, PA28 (various specimens of the foregoing, as found at a certain airport which you know about), TB10, TB20 (several ones), SR22, DA42, C421C, an RV6 (or RV8?) and maybe a few others I don't recall right now. None of them had static roll stability, meaning that you could just trim it for wings level, altitude not changing, and it could be left like that indefinitely (hours). My TB20 can go (I've tried it) for anything up to a few mins before it is entering the old spiral of death, which is highly stable and makes for very easy long distance manual flight, but that is a completely different concept from total static stability in which any reasonable departure from wings level will restore the wings level condition.

One can achieve total roll stability with a lot of dihedral, and/or other ways, and it's easier if the COG is below the centre of lift (as in high wing planes) and this is routinely done on model aeroplanes which often don't have ailerons - just a rudder, and in some cases not even an elevator.

I've just checked this out with some other pilots and also aircraft design experts so I am happy enough.

Last edited by IO540; 13th Oct 2008 at 17:20.
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Old 13th Oct 2008, 17:39
  #206 (permalink)  
 
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Fuji - I think that either somebody (not you) is taking the p*ss out of me as usual, or we are talking with wires crossed.
Nope, you have just become paranoid.

I still maintain and so does my engineer that any aircraft that descends into th spiral of death that you are indicating is probably down to being miss-rigged or miss-loaded.

I have just done a flight test in a Chipmunk and lo and behold, trimmed it out straight and level and flew along for several minutes in a straight line with out any inclination to start a turn or head for a dive.
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Old 13th Oct 2008, 20:05
  #207 (permalink)  
 
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Spiral stability is covered in many standard texts. From Thom...

The lateral stability characteristics of the aeroplane, such as dihedral, cause the lower wing to produce increased lift and to return the aircraft to the wings-level positions. There are two effects in conflict here:

- the directionally stable characteristics (large fin) want to steepen the turn and drop the nose further; and
- the laterally stable characteristics (dihedral) want to level the wings.

If the first effect wins out, i.e. strong directional stability and weak lateral stability (large fin and no dihedral), then the aircraft will tend to bank further into the sideslip, towards the lower wing, with the nose continuing to drop, until the aeroplane is in a spiral dive (all without any input from the pilot). This is called spiral instability.

Most aircraft are designed with only weak positive lateral stability and have a slight tendency to spiral instability. This is preferable to the reverse situation - an effect called Dutch roll.
Further reading... AvWeb - The Deadly Spiral
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Old 4th Nov 2008, 00:48
  #208 (permalink)  
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DNA tests have confirmed that the remains in the aircraft were those of Steve Fossett.

BBC NEWS | World | Americas | Bones confirm Steve Fossett death
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Old 13th Mar 2009, 04:09
  #209 (permalink)  
 
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Impossible to prove, but as a private pilot who's known to talk to himself in a tight situation, how's this for a scenario?
"Lovely day for flying -- Wow, I see some lakes over there, think I'll take a look-see. May want to do a water speed record if it's suitable. -- No, too small, I don't think that'll do it, but do I see another lake, a little further on? If not, maybe I could find some really flat land to break my land-speed record -- No, nothing here, I suppose I could land and look around -- Oh oh, must change my mind, it's late, and I'm way off track and people are waiting for me. -- Come to think of it, I didn't file a flight plan, but who does, these days, I didn't know where I was going anyway on such a nice day -- I'll just have to take a short cut through that range over there and straight line it home -- What, no VOR, no navigating instruments, no landmarks? Is the fuel gauge good on this aerobatic machine? Where the hell am I? Ages since I practiced instruments anyway -- Seat of the pants? This is absurd, for me. Ironic indeed -- Geeez, look at the fuel gage! Where is it? I'm nearly out, if I go down, my cell phone won't work -- Don't panic, everything will be alright -- There's a gap! Thank God, I'll go through it, bound to take me home real fast, or then I can glide. Oh for a balloon! -- SHEEEIT, it doesn't go anywhere. Is this what they mean by a Box Canyon? -- Can I make a tight turn to the left? How about to the right? -- Too late, better release my harness and hope for the best. Maybe I can get out if the landing's not too hard. Don't panic. Stay cool." C-R-A-S-H!! Curtain.
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Old 13th Mar 2009, 09:58
  #210 (permalink)  
 
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Why so complicated? An older experienced pilot had a stroke or heart attack...
He had a great life and died doing what he loved
End of story
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Old 13th Mar 2009, 12:17
  #211 (permalink)  
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Tfor2's imagined "complicated" scenerio is largely preventable with self discipline, the simple scenerio much less so. Reminding ourselves to fly with discipline is never a bad thing.

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Old 13th Mar 2009, 12:19
  #212 (permalink)  
 
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The NTSB seems to think he was trying fly over the ridge and got caught in an unexpected downdraft he wasn't able to outclimb the terrain. Heart attack, etc. you would normally expect it to look like a loss of control accident rather than CFIT.
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Old 15th Mar 2009, 07:15
  #213 (permalink)  
 
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Think so? Check out the story of Frank Tallman, a very experienced pilot, and his partner, both died for no good reason.
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Old 15th Mar 2009, 22:09
  #214 (permalink)  
 
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That Wlki link is to CFIT in IMC. I find it hard to believe an experienced glider pilot would have got himself into the position in the first place, and that a pilot of Fossett's experience would have crashed in the way he did, if fully conscious.
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Old 16th Mar 2009, 07:30
  #215 (permalink)  
 
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NTSB Report

Mountain flying is for experienced locals. Winds, density altitude, and familiarity with the plane's performance suggest he should not have been flying alone. Or not gone adventuring.

Here's the report: SEA07FA277
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Old 16th Mar 2009, 07:56
  #216 (permalink)  
 
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I've just read the whole report. It sounds totally inconclusive. In particular, unless I have missed something, no conclusion whatsoever could be reached regarding medical factors.
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Old 16th Mar 2009, 17:54
  #217 (permalink)  
 
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Inconclusive but with a lot of important facts
  1. It was a severe clear day - No clouds, 60 miles viz (so CFIT in IMC is not a real possibility
  2. It was way above standard and the POH says 370 fpm is the best the aircraft would do at the accident site.
  3. There is a radar track at the right time and place that has no irregularity worth commenting upon (other than the loss of Mode C).
  4. The debris trail and impact signatures seem consistent with CFIT .
  5. [Opinion]the two points above are not consistent with a medical emergency.
  6. There was 35 knots (from memory) of wind across the mountain.
  7. The NTSB commissioned a meteorological analysis that indicated downdrafts in excess of the aircraft's maximum climb rate would have been expected at the crash location.
  8. PIREPS indicate very smooth air interrupted by quite bumpy periods.

No conclusion is reached, but inadvertent IMC or medical issues seem remarkably unlikely to have anything to do with this accident.
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Old 16th Mar 2009, 18:26
  #218 (permalink)  
 
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Its bewildering why Fossett thought that he could undertake such flight without the assistance of his retinue of paid experts who would normally do all his flight planning and navigation.
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Old 16th Mar 2009, 21:06
  #219 (permalink)  
 
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Hi,

"3. There is a radar track at the right time and place that has no irregularity worth commenting upon (other than the loss of Mode C). "

The radar track reached 14900ft and there is no mention that he used oxygen.
If he did not, a loss of consciousness is quite possible.
With a climb rate of 300ft/min, the climb from 12000ft to 14900ft would have brought him over the legal limit for nearly 10 minutes.

Joe
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Old 16th Mar 2009, 21:20
  #220 (permalink)  
 
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Its bewildering why Fossett thought that he could undertake such flight without the assistance of his retinue of paid experts who would normally do all his flight planning and navigation
Please explain. This bloke had some 6k+ hours. Maybe many not in pistons?

The radar track reached 14900ft and there is no mention that he used oxygen.
If he did not, a loss of consciousness is quite possible.
With a climb rate of 300ft/min, the climb from 12000ft to 14900ft would have brought him over the legal limit for nearly 10 minutes.
Yes, FAA-illegal perhaps but not a risk re consciousness unless he had a medical issue.

It does appear that he was flying pretty close to the actual aircraft ceiling, so would have been going fairly close to Vs and it would not have taken much of a downdraught to bring him back down. However, in that situation and faced with celarly visible obstacles one would have turned around. The wreckage was of a very high speed flight straight into the mointain.

It doesn't make sense to me at all.
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