this was a loss of control after apparent inadvertent VFR flight into IMC
Did they get the data from GPS?
I am sure very few loss of control in IMC incidents end up in an AF447-type stall and going down vertically with almost no forward speed. Normally if you lose control in IMC you end up in a spiral dive but the plane is flying normally, straight ahead.
V tail Beech Bonanzas averaged of one fatality per month
That’s absolutely amazing!
Peter wrote:
Did they get the data from GPS?I am sure very few loss of control in IMC incidents end up in an AF447-type stall and going down vertically with almost no forward speed. Normally if you lose control in IMC you end up in a spiral dive but the plane is flying normally, straight ahead.
They suspect a stall/spin type accident, so not AF447. In a turn, he supposedly entered cloud, then pulled hard and decreased the speed to a stall. All that’s missing then to enter a spin is some uncoordinated rudder input. They cite a Safety Communiqué 147 “Spin Avoidance and Spin Recovery Characteristics” by Beechcraft (which I can find nowhere on the Internet, even on Beechtalk in a discussion it is mentioned as attachment but missing there), according to which it can be impossible to recover a spin on that type of plane. But even if it were possibly recoverable, at that altitude, following spatial disorientation in cloud, it isn’t hard to imagine how such a spin could be maintained to the ground.
Re available data: They had radar data from two stations with a 5 second interval, and they describe the calculations they made to assess the precision of the deducted trajectory at that place (e.g. 600 ft/min precision on the vertical speed) in section 1.19.
Peter wrote:
That’s absolutely amazing!
I’m trying to find the old circa 1980 article with the V-Tail Bonanza in flight structural failure record, I can’t find it on line now, but I believe it was Aviation Consumer article (?). The record and discussion was very controversial, but to me the interesting thing is that after the ADs about 35 years ago the record was very much improved. Like many things in my engineering experience, I think it was never entirely established what was happening but at some point and with enough changes the problem went away.
PS here is the article
DavidC wrote:
I think this relates to PH-UBG, a TB21 which crashed on 10 April 2001 in Belgium (Neeroeteren). The event is so old that the accident report is no longer online.
Here’s the accident report. I’ve asked Peter to store it somewhere.
QuoteV tail Beech Bonanzas averaged about one fatality per month due to inflight structural failures over a period of about 30 years, late 40s to roughly 1980 when FAA applied some ADs that apparently worked well. Three or four hundred fatalities in all, IIRC. I’m sure most of those were weather related, in conjunction with rudimentary IMC instrumentation and the characteristics of the plane and pilots.
Silvaire, do you have the specific reference quote for that statistic. I would question it. My view is that there were a couple of accidents where deliberate, or inadvertent entry from VMC, into IMC, with the non experienced pilots stuffing the nose down, rapid speed build up, into loss of control, into plane breaking up. The adverse publicity came due to this being an innovative design, way before its time, fast, dependable transport for the reasonably well healed. The term Doctor Killer was given, because it was this wealth band that could a) afford it, and b) provided suitable transport throughout the US. Needless to say, Beech bowing to some adverse publicity, and potential lawsuits, on its new dream machine, worked hard at PR, one aspect being a strut strengthened and enhancement AD. Nothing was actually ever proven that the aeroplane was structurally defective.
Pity we could not AD some pilots……
BeechBaby wrote:
Silvaire, do you have the specific reference quote for that statistic.
Did you read the article linked to in post #13? I found it very interesting and well researched.
RWY20, sorry, no, I did not. I will now. This aeroplane operates in cruise, near VNE, and whilst a stable platform, is quite tricky if allowed to get out of the pilots capacity. I suppose you could argue that about all planes. It flies like a mini airliner, and should be operated by the numbers. There have been a fair few who have found this out the hardway. Obviously moving through VNE, in a spiral dive, generally something may break. In the case of the V tail, early days, it was the tail section. I also suggest that there is a large knowledge gap in maintenance, and a very well, and correctly maintained airframe, should assist in keeping the pilot safe, even when he gets the plane into situations that do not auger well. Secondly, if rigged incorrectly, flutter can be an issue. A number of V tails have been flying, mine included, with incorrect rigging. Mines has been fixed by the way…..the previous riggers were Part145, who managed to rig it, without a jig…….I discovered this, after the event of course..
This EuroGA article of mine looked at the accident history of the 182 vs 210 for 2000-2010. Only one 210 was lost to in flight break up in convective weather during the period.
https://www.euroga.org/articles/technical/accident-statistics-in-imc
I have not been able to prove it, so apologies if it is an OWT, or geezer patrol myth, but the fixed gear 172/182 series may have never experienced an in flight break up in convective weather in the US – bent wings yes, wrinkled tail cone, but not a break up.
BeechBaby wrote:
This aeroplane operates in cruise, near VNE, and whilst a stable platform, is quite tricky if allowed to get out of the pilots capacity. I suppose you could argue that about all planes. It flies like a mini airliner, and should be operated by the numbers.
Yes, but that would be true of the 33 and 36 series as well, would it not? Apparently they have an excellent in-flight break-up record.
