The D113 is a 100hp 0-200 and have been used for mountain flying for many years and I believe FPLUM has landed on glaciers mant times. I wouldn’t think that it has a problem of reaching 8700ft normally. Were the temeperatures that day particularly high?
But flying onto glaciers is a lot more high risk than landing in the plains, for many reasons.
Jujupilote wrote:
The D113 is light but powered by an O-200. Quite sporty in the plains but I wonder how it behaves at 8700ft, the altitude of the crash.
It has also been incredibly hot here the past couple of weeks with a lot of convective activity. Temperatures of up to 10,4 degrees at the summit of Mt Blanc at 4750 (15600ft) metres on the 19th and the 22nd which is a new record… Density altitude would have been above 11K ft at the site of the crash – not at 8500ft (2600M) – for a Jodel with potential downdrafts not an easy thing to overcome…
I flew past Brevant last year, the other side of the Chamonix Valley, at MTOW in a D140 and caught an up draft. At idle I was top of the green airspeed and climbing 1500 fpm. When that air wants to move you, it will. Same for downdraft. As you say, record temps at the MB summit last week. I’m guessing prob a significant factor ?
Really sad accident but I always hear the talks about mountains & up/dndrafts, piston performance, high density…lot of it talks about engines and aircraft types?
- I am not aware of any type that can outclimb rotors, even B737 will go to the rats like D113 in the gully, maybe only F18 can outclimb it?
- Gliders fly fine in mountain without an engine with high density altitude and lot of wind
High level, it has to be something completely unrelated to aircraft type & performance? like being in the wrong place? or the wrong day? not pushing the stick forward enough to quickly get out of -4kfpm? you gotta do it !!
Ibra wrote:
High level, it has to be something completely unrelated to aircraft type & performance? like being in the wrong place? or the wrong day? not pushing the stick forward enough to quickly get out of -4kfpm? you gotta do it !!
Don’t disagree Ibra, but I assume (it doesn’t say in the article) they were trying to land on the glacier des Argentieres which is tricky on a good day, doesn’t really allow for a go around…
Temperatures of up to 10,4 degrees at the summit of Mt Blanc at 4750 (15600ft) metres on the 19th and the 22nd which is a new record
That’s incredible – ISA plus 27C. That will depress the operating ceiling of a TB20 (which has loads of power) by something like 7000ft.
Peter wrote:
That’s incredible – ISA plus 27C.
ISA plus 27C is not a good day to go mountain flying with any SEP. Wonder why they even tried it, the instructor must have been aware. DA is a killer.
If it’s true that such a DA is not helping the planes to fly, pilots and instructors knows it, and you come to try and exercise at which point it is limiting you, to face these effect in a safe manner. The fact that they actually climb that high is telling that the plane was able to do it. I actually tested landing on some surfaces with 20kn rear for the sake of exercise with my MOU instructor, to see how much it degrades. I would surely not do it outside these conditionsThat is the same for DA and small engine, so I would not jump on conclusion that fast.
Looking at weather data I estimate DA to almost 10,000 at 8,700ft. That is not very comfortable, but the D113 should go up to FL140. Yes it is a rather light aircraft, but I did like it for mountain flying.
greg_mp wrote:
That is the same for DA and small engine, so I would not jump on conclusion that fast.
A quick calculation gives me a DA of about 11.500 ft. The thing is, while the airplane still flies, it is operating at the edge of the envelope and doesn’t have any spare power to overcome even the smallest upset.
Neglecting the effects of DA kills several people inn the mountainous parts of the western US every year.
