That’s probably the only general tip that works everywhere. Hence, Cub, RV or any other plane with good climb performance is a better choice.
That being said, we had a fatal accident a year ago in an RV that probably were caused by this very phenomenon although nothing official as of yet from the investigation.
Are there any general tips for this?
Obviously if you have the climb performance to climb straight out then that’s the simplest option.
LeSving wrote:
Whenever there is a gradient in the wind, with respect to time or position,
…which is called “wind shear” — which I mentioned.
Airborne_Again wrote:
No, that’s an old myth
No it’s not. Whenever there is a gradient in the wind, with respect to time or position, you will have effects like MD is describing. Wind shear is another name, but usually only describes strong horizontal gradients that can be dangerous for airliners. There are always gradients, even on flat surface, but in the mountains they are much stronger due to the terrain. In a flat landscape you can more or less forget about it, there is only “wind and gust” (most of the time, unless you are landing a glider).
I know what you mean. An aircraft will fly with the wind, like a boat on Amazonas, thus turning makes no difference to the aircraft in relation to the air mass. IMO this is a very stupid and dangerous picture to have, because a constant wind (in all directions and with respect to time) is an idealized situation that never exists in real life. This situation causes no problems. That’s the point about it, it causes no effect on the aircraft whatsoever, because the aircraft is also moving with the wind.
Gradients cause huge effects on the aircraft.
I try to create new threads out of off topic posts when the new topic is one of general interest to pilots.
ok I think the purpose of the original post got high jacked for long enough..
By9468840 wrote:
I agree. It is not like the aircraft turns from departure heading to downwind at an instant. It does so by gradually hence the airspeed remains practically uneffected.
Even if it did turn in an instant, it wouldn’t affect the airspeed as long as the wind was constant. Only wind shear would affect the airspeed.
By9468840 wrote:
If there is a risk of Maloja wind, wouldn’t departing 030 with a bit of a tailwind of course assuming the whole calculation checks out with high altitude take off performance etc. be an option?
Yes. Normally in this situation, it is far less dangerous to depart with a bit of tail wind and follow the valley straight out direction of Zernez than to negotiate a turn in the Pontresina baissin. I’ve done this every time I could get away with it.
If there is sufficient headwind on 21, then of course your climb will be so that you are higher over the critical area already. So most of the time when the wind is too strong for a 03 departure, that would compensate for the risk a bit.
I am not sure if the Malyoa Wind is indicated on their Information Display which includes quite a lot of good information otherwise, but certainly the people at the airport know about it. Simply ask.
Airborne_Again wrote:
No, that’s an old myth.
I agree. It is not like the aircraft turns from departure heading to downwind at an instant. It does so by gradually hence the airspeed remains practically uneffected. The main problem here with 21 looks like the downdraft as soon as the aicraft crosses the leeward side of the terrain, while turning downwind. The airspeed would reduce because of pilot error while trying to keep level against the down draft. I have never been there but looking at their Pilot Briefing material, it seems to be a real danger.
They have a 1.8km runway. If there is a risk of Maloja wind, wouldn’t departing 030 with a bit of a tailwind of course assuming the whole calculation checks out with high altitude take off performance etc. be an option? Does anyone know if Samedan reports Maloja winds status and speed?
Are there some general tips on how to do these operations?
Obviously you need to be aware of engine management issues for altitude ops.
Another thing you get is that sometimes the canyon is not all that wide and after departure if you have to do a 180 then you may want to fly over to one side of the canyon before doing the turn, to give yourself extra space. But the published circuit may not allow that. I had that in Bolzano, visible here from 41:00 onwards
