Val d'Anniviers Airplane Crash
 

http://static2.hln.be/static/FOTO/pe...20110211183320

No survivors.

Sion is LSGS not LSZS.

I stand corrected; thank you.

My comments on radar and MSLP still stand. No apparent high altitude weather.

From here

METAR LSGS 111220Z VRB03KT 9999 FEW110 11/M07 Q1019 NOSIG

TAF LSGS 111125Z 1112/1121 VRB03KT 9999 FEW110
BECMG 1113/1115 CAVOK=

No real difference.

This shows nothing before 1800Z now but you can see no significant high altitude cloud over most of Switzerland.

I am no crash investigator but to me it looks like they tried to land along the top of the ridge but thoroughly stalled and hit the ground with a high vertical speed and low horizontal speed. A bit like the Turkish B737 in Amsterdam. The huge (1m) boulder about 2m behind the elevator seems undisturbed. Except for footprints, the snow is undisturbed all around.

Why would you ever want to land there though? From that position and at FL 120 you can make it down to the Rhone plain and various airfields there with altitude to spare even with dual engine failure.

Perhaps stalled it when he found he couldn't clear the ridge and it was too late for a 180?

How's a B55 doing with 3 adults and two teenagers?

It's a pretty good stall though, shame no one survived, by the shape of the fuselage there was a possibility of surviving?

What is the single engine ceiling of this aircraft, at MTOW?

Fully stalled one is probably doing about -10000fpm i.e. 100kt. That is what happened, apparently, with AF447.

Huh? I can't speak for either a Baron or an A340, but the planes I fly can be held in a full stall and fly quite decently, coming down at around 1000 fpm. I do this routinely in my plane (TR182) and the Pitts, and have done it in a 172, Citabria and Decathlon. It would seem kind of weird doing it in an A340 but I don't see why it would be much different.

I wouldn't want to hit the ground even at that kind of vertical speed, though.

A spin is a different matter of course, but it doesn't look as though he was spinning.

The weather in and around Sion, especially in the valley, can change within minutes. It was a procedure of ours to go and eyeball up the valley pre departure because you couldn't rely on the actual weather report still being relevant.

I've actually got airborne in, essentially, CAVOK conditions, done a 180 back down the valley to be confronted with a huge banner cloud that wasn't there two minutes earlier.

Must have been hell of an impact, looking at how the wings have deformed yet the tail looks ok, so probably nose low.

It does make one wonder why you'd try to land there rather than circle off down the valley and use your height. Does to me look like they stalled, the Baron has quite a high stall speed if I recall correctly.

That's because you still have a forward airspeed. My TB20 glides down at about -1000fpm.

If one killed their airspeed completely, that's different. It won't be easy because any certified single engine plane, loaded within the envelope, will go nose-down and recover.

But if you were to overload it heavily in the back, then it might not recover, however, and will just go straight down.

This is outside my area but multi engine planes do not have to meet the 61kt Vs and AIUI do not have to recover from a deep stall. This is one thing which came out of AF447; an A330 can just stall/spin and plummet straight down, unrecoverably.

I reckon this one came down at a huge VS.

LSM - I agree; nothing suggests they were VMC or IMC at the time of the impact. But looking at the terrain, and the fact that they are pointing just right along that ridge, I reckon they tried to come down on it.

Picture 4 on 20 Minutes Online - «Le pilote et une famille sont morts» - Romandie gives a good overview of the surrounding area.

They have crashed at about 3.000m at pointe de la Forclettaz.

The family was French with children aged 15 and 11

Does anybody know anything more about this, e.g. ATC interaction?

It does seem a bizzare accident. Obviously not a straight N2195B-type CFIT. It's obvious the plane went more or less straight down, in a straight and level attitude, perhaps a bit nose-down. Could be fuel exhaustion followed by less than competent aircraft control, or pilot incapacitation followed by a passenger attempting to fly.

The temperatures (+11C at Sion) don't seem low enough for a dual engine failure due to fuel icing. The Aztec has been reported to ice up below -15C. I know nothing about the Baron. But it's possible, if they were flying high (say FL200+) to start with.

It is also quite possible for that ridge to have been one of not many sticking up through a high altitude cloud layer. This might explain why they did not go into the valleys surrounding the ridge.

No signs of post-impact fire either, despite all the fuel tanks having been most likely torn open. It doesn't suggest large amounts of fuel on board, at the time of the crash.

As a side note, looking at those pictures I'm always grateful for the people in the rescue/recovery team: a job as valuable and essential as it is gruesome.

Must be horrific for them, especially when kids are involved. Not sure I would choose to do it.

I was flying VFR SEP in Switzerland on the day of the accident, I'm based and was flying in the eastern part but have a good look at the weather and particularly winds for the whole of the country before taking off.

There was the usual mist over the 'plateau' that morning but around Sion and over the Alps it was 'grand beau'. Winds were SSW 15-20Kt between 8,000 and 13,000ft.

The accident site is a ridge above the Pont de Forcletta at around 3000m or 9500ft.

The aircraft was based at Geneva, it flew to Lausanne, picked up the 4 passengers and departed for its sightseeing flight. The pilot apparently intended to land after this at Sion.

The accident site is outside the Sion CTR/TMA in Class E, the pilot would not have had to be in contact with any ATC unit but might have been in contact with Geneva Information.

I flew the Baron in 1970-71 at Hamble but never at high altitude with 5 on board. I would think that the aircraft was above its single engine service ceiling, however it looks as though the aircraft impacted vertically with zero forward speed. I would speculate on pilot incapacitation followed by stall and spin.

There don't appear to have been any witnesses, I would think that the flash memories of any installed GPS set and passenger cameras will yield important clues.

Interesting to see how the wings are draped over both sides of the ridge. I can see how it supports the idea of a near vertical descent, or one normal to the ridge slope.

Ridge level winds are normally considerably more than that reported in the valley bottoms. There can be eddies from adjacent peaks and spurs, but downwind of a ridge is a very nasty place to be. The sink can be enormous. Directly over the ridge is a transition zone with considerable curl over. I would lean to an angled approach from downwind that hit heavy sink.

How close to the terrain would you need to be to get a sink rate exceeding the rate of climb of a Baron at MTOW at 9500ft, with ~ 20kt winds aloft?

Quite close I would think. A few hundred feet; possibly a lot lower.

I don't do any "mountain flying" but have flown straight over the top of the Alps and the Pyrenees a number of times.

However I don't believe winds could have done this. The aircraft hit the ground with a massive vertical speed. Looking at the pictures, at least two seats were ejected out of the cockpit, several yards out, ripping off the roof in the process, all despite a near-zero horizontal speed. One to the right and behind, one to the left and over the LH engine. Both ejected with occupants still strapped in (visible in the first picture). Horrid.

Looking at the pictures there seems to be higher terrain somewhere near that ridge. I don't know what the winds aloft in the area were like at that time, but a priori if they were on the lee side the effect of a downdraft or worse, a rotor (:uhoh:) is a distinct possibility.

Can anyone post the coordinates?

I don't reckon a rotor would do this. Looks to me they hit nose down - in fact almost "flopping" onto the ground in a very hard impact. In a down draft the nose would be up, but in the picture the tails is in perfect shape, with heavy damage to the front / wings (look how flat they are but not bent backwards) so I agree with IO that they were nose down with low forward speed, high vertical speed so probe noably stalled before thse went down.

Actually those pictures are pretty shocking. I don't recommend anyone lets their partners see them or they will never get in a light aeroplane again. I am just glad that it would have been quick judging by the damage.

File:Pointe de la Forcletta - Depuis Sorebois.jpg - Wikimedia Commons

This is a picture of it as well as a correct spelling, it has nothing to do with the col de la Forclaz

IO pls check your mail

I was taught to approach and cross a ridge at about 45 Deg angle. So if you got downdraft or another plane coming the other way you only have to turn 45 Deg to avoid crossing if needed. Maybe this is what was involved?

As far as how close to the ground to get downdraft or updraft. I was shocked. My instructor expected me to fly within feet of the side of the valley to get full benifit of the updraft. He did say not to get closer than about 10 feet :sad: (he did say feet dispite being French)

Mountain flying and landing on "imposible" spots - best flying I have ever done :ok:

vanHorck - I found that ridge OK in google earth but none of the background views match those in the crash photos.

I was wondering what could have caused the roof to blow upwards like that, rip out the roof pillars, and to eject the two seats. I reckon an oxygen cylinder blew up. Car bombs do the same thing - the roof looks curved. Must have done so after the impact because one of the seats ended up on top of the wing.

Not if you're stalled. Then you go down like a sack of potatoes you do. :ouch:

Looks like an accident due to a ridgeline downdraught to me. Rotors develop below ridgeline level and away from the terrain. Sounds like the winds were strong enough to have easily caused a problem, remember that winds will be significantly stronger (maybe more than 2x) crossing high terrain like that.

I've been through severe mountain downdraughts a few times, one time my VSI maxed out (2,000ft/min downwards) instantly.

An updraft would increase AoA and can cause a stall, depending of course on how fast they are flying.

I reckon the crash site is on the ridge running to the north from the Forcletta pass to the peak 'Le Boudri'.

http://i38.photobucket.com/albums/e1.../forcletta.jpg

The village visible below the crash site is probably Ayer.

Maybe I'm completely mistaken, in any case this site will publish a preliminary report in a few days:

BFU - BEAA - UIIA - AAIB

The general wind was south westerly, this is known in the Alps as 'Foehn' and can be unpleasant, but on the morning of the accident winds were not strong enough to produce significant downdraughts or rotors. They were certainly not a problem where I was flying 100 miles further east.

From the Forcletta the ridge rises to the south east up to the Weisshorn at over 14000ft.

If these were the winds at the time I would have thought that they could be strong enough to cause an issue in the mountains. My rule of thumb is for 20kt winds I would need to clear a ridgeline of 9,000ft by 1,500ft+ minimum, and ideally 2,000ft+. Obviously it depends on the direction of the wind in relation to the ridgeline, my figures are for where they are perpendicular.

My eTrex keeps a track log, but do GA GPSs (like the Garmin x96 or x30 range) do that too? I've never seen that.

Winds or mountain waves cannot explain why this plane hit the ground with zero apparent forward velocity.

FWIW, my rule of thumb for a 500fpm up/downdraught is 1000ft above the peak(s) for every 10kt of wind aloft.

Crossing the Alps, I would normally be at FL160-190 which tends to be at least 5000ft above the terrain. I have never seen any significant turbulence. The worst I have had was a boat-like ride which was disconcerting to my lady passenger but, with the autopilot holding altitude, there was no apparent variation in speed.

Normally, entering e.g. a downdraught, and using the AP to hold altitude, you see a airspeed drop and a pitch-up, obviously. I've seen plenty of those, and also the opposite. But I don't cross the Alps in poor weather, and neither was this pilot. Also, the ridge was some way from the nearest other ridge and I can't immediately see how one could end up where he ended up purely as a result of turbulence (a rotor, etc).

No IFR GPS unit I know of keeps a track log.

I am curious why you think zero forward speed?

My humble Garmin 196 does keep a track log, with a selectable resolution whose factory default is one point every 30 s.
There are a few AAIB accident reports that include track logs downloaded from portable GPS units, although in many cases the owner never modified the default resolution, making the log not as helpful as it could have been.

No apparent backwards bending anywhere, the wings are completely flat yet still "connected", no apparent disturbance immediately behind the aeroplane etc.

In a down draft you'll be trying to climb, which is why the nose would be up. If you stall, well, that is just bad piloting, but if you didn't and you hit the ground it would be in a nose high attitude.

15-20 kts shouldn't give too many problems around mountains, especially if clear of them by >1000', it might be a bit bumpy but I wouldn't have thought that there was anything nasty enough to cause this crash.

Accidents involving "more advanced" aircraft do tend to draw attention (here, anyway) because pilots of those types are more interested in learning from others' mistakes. If somebody prangs a C150, it doesn't draw much attention. Whether a pilot of a Baron is necessarily any more smart than a pilot of a C150 is another matter (probably not, but he ought to be).
If trying to hold altitude, sure.

I saw the MSLP chart for the time but haven't got it saved. It didn't show much wind.

G1000 can do track log
 

Not really relevant here, but FYI if you plug an SD card into the top slot of the MFD in a G1000 it records just about everything, once per second. (Time/date, Lat/Long, IAS, TAS, pressure, heading, altitude, vertical speed, wind speeds, fuel pressure & flow, engine rpm, oil pressure, engine temps, roll, pitch & yaw attitudes and rates...).

This may very with software version, but works in my DA40 (useful for monitoring performance over time - hopefully it won't ever be needed for post-accident but clearly pretty helpful for that, assuming the SD card survives).

Alan,

I do not think you appreciate what a sudden change in AoA to a high negative number will do to your flying.

Forgot to say, in a forceful downdraught, your strategy is to maintain airspeed first, then get out--normally by turning downhill. Trying to climb is not normally an option.

There is a ( now) mandatory Beechcraft AD requiring the replacing of the lower wing bolts and a mod to the lower wing bolt attachments in the spar - All B55/B58 types now HAVE to comply - could we be looking at the first in flight failure of such bolts - wings pivot upwards = high rate of vertical descent ala leaf ?:\