Qalupalik wrote:
The glider charts use metres for vertical distances.
See the legend in the documents box at the bottom of this Swisstoto page
the glider maps yes, but not only in Switzerland
I have come across German “sports gliders” that have metric ALT/VSI and ASI in kph, load of them fly in other countries using km for map distances and tasks (actually legacy from FAI sports records that are in meters) but I don’t think they look that much to their instruments even when flying waves in the Alps…
Neal wrote:
Speed is credit – altitude is cash
Of course. But, the ability to climb is also important. You are at 6000 feet with mountains around and have the ability to do some OK climbing. Then you are at 8000 feet and very poor climb rate. OK, alt is cash, but you still have mountains around at 8000 feet, so the only thing that has changed is you have lost a good deal of climb rate. Crossing ridges and passes are best done at some alt, lets say 1000-2000 feet, but that alt is only needed if you close your eyes to what is going on with the air masses.
LeSving wrote:
But, the ability to climb is also important. You are at 6000 feet with mountains around and have the ability to do some OK climbing. Then you are at 8000 feet and very poor climb rate.
OK, Pipers aren’t great mountain or, in a more general sense, high-altitude airplanes, but suggesting that an Arrow IV cannot climb from 6k ft to 8k ft even on an ISA+20 day is ludicrous.
Gigicret wrote:
where did you find aviation maps in meters in Switzerland ??
Unless you fly with road maps?
I didn’t – just talking hypothetically. My point is if you have an idea where you are in the world (particularly planning stage) and a bit of geographical awareness it should be obvious if figures you see on ANY map / chart / road / glider etc are in feet or metres.
We all know that very approximately 3 foot = 1 metre (3.28’ = 1m) – it’s a threefold difference !!
So if you see a figure like 6000 in the general Alps area it’s sure is feet – very unlikely to be 6000m / 18,000 feet.
What I’m sure we all know as a ‘gross error check’.
172driver wrote:
OK, Pipers aren’t great mountain or, in a more general sense, high-altitude airplanes, but suggesting that an Arrow IV cannot climb from 6k ft to 8k ft even on an ISA+20 day is ludicrous.
our Robin (even the 160hp) up to 14’000ft, the 180ch is even mounted above Mt Blanc
Ibra wrote:
I have come across German “sports gliders” that have metric ALT/VSI and ASI in kph, load of them fly in other countries using km for map distances and tasks (actually legacy from FAI sports records that are in meters) but I don’t think they look that much to their instruments even when flying waves in the Alps…
historically gliders fly in meters and km/h
172driver wrote:
OK, Pipers aren’t great mountain or, in a more general sense, high-altitude airplanes, but suggesting that an Arrow IV cannot climb from 6k ft to 8k ft even on an ISA+20 day is ludicrous.
I’m not suggesting that. What I am saying, or rather wondering about, is how wise it is to fly as high as possible IF the aircraft starts to fall behind on climb performance and IF you have mountains around no matter what. This “stay 2000 feet above the peaks” is OK, when it is possible to do that, but that’s not the only choice, and not always possible.
The general idea with crossing mountains is that one climbs above the terrain well before reaching it. That establishes the climb performance in good time, and makes it almost irrelevant because by the time you get to the mountains you are in level cruise and doing a decent speed, and it allows you to see ahead and check for bad wx.
That is of course not “mountain flying” which is flying inside the canyons, and I don’t know how one would do that equally safely. I think one can get wx briefings for the GAFOR routes, plus there are webcams.
A PA28-161 can do 11k at about ISA+7 (my own experience) and a PA28-161 can probably do about 14k at ISA. A PA28R should be able to do 15-16k.
LeSving wrote:
I’m not suggesting that. What I am saying, or rather wondering about, is how wise it is to fly as high as possible IF the aircraft starts to fall behind on climb performance and IF you have mountains around no matter what. This “stay 2000 feet above the peaks” is OK, when it is possible to do that, but that’s not the only choice, and not always possible.
The most important thing is to never engage in a pass, on climbing !
Reach the necessary altitude and then commit yourself!
Thus, you will have enough speed to be able to turn back safely and enough altitude to pass. In addition visibility will be better
