Hi Raimo Toivio,
> whats a minimum altitude which make sense when overflying The Alps?
You can fly IN the Alps, and you can fly OVER the Alps. Personally,
generally I fly over the Alps, except when I need to land in a field
inside the Alps. Flying between the mountains instead of over them bring
all sorts of risks, especially if you are unfamiliar with the area. Even
when flying between the mountains, I will do that only if there are no
clouds above and I always have the ability to climb out of nasty
turbulence, upsloping valleys, or a traffic jam (I had one time had the
pleasure of almost getting into a swarm of a dozen or so motorized hang
gliders that suddenly appeared around the corner of some mountain peak.)
See and avoid is a whole new game between the mountains, and radar
doesn't get there so ATC is unable to advice, and the most traffic warn
devices are transponder based but transponders remain silent when they
are not triggered by radar. Local radio is useless as well as most local
traffic tends to communicate in some sort of crypto-language instead of
plain English. We've just installed Flarm because that is the only thing
that offers some protection.
About the altitude required, that depends a lot of the area you are
crossing. For the area where Ilona's parents live you can get away with
FL100, but for a straight line from Croatia to South Germany we had to
climb to FL115 but even then we had to zig-zag here and there to miss
the tallest mountain peaks.
One warning here: if there is some wind, there are likely mountain
waves. With the turbo it is generally possible to outclimb down washing
area's (except when there is more than just some gently wind, it can
drag you down with 1000ft per minute and in severe cases it can even
suck down an airliner.) and of course it can also push you up. Have been
flying there once with a C172 with the power at idle and quite a nose
down attitude but still climbing with over 1000ft/minute. Not funny if
you are passing FL120 in a hurry without oxygen on board.
That was when I didn't had a clue about how mountain waves flow, with
later insight I had easily got out of it if I just changed the heading
90 degrees. Some basic understanding how (invisable) mountain waves flow
is really helpful.
Always be prepared to turn around quickly if something undesirable
happens (and one more reason to be above a valley rather than in it).
There are interesting theories on the internet about the best way to
turn around in a narrow valley (including stall turns etc) but the best
way is to avoid getting into a situation where this is your only way
out. Approach ridges always at an angle and never fly straight to them,
this to make it easier to turn away if you are sucked down just before
crossing (or hitting) the ridge.
Anyway, mountain flying is a bit more risky than flying above a flat
country with many pastures, but being aware of all the dangers keeps you
sharp and helps to avoid nasty situations. I'm always looking for
emergency landing spots and even adapt my routing to stay within range,
but I have to admit that sometimes there isn't any suitable spot and if
the engine dies you have a not so nice situation. I'm always relieved
when I approach the next valley and it happens to be one with green
pastures rather than one with just a rocky river at the bottom.
Our Alps crossings to Croatia were uneventful, despite quite a nice wind
that sent us with over 160 knots GS to the other side but didn't cause
any turbulence or other nasty effects at all.
Seen the picture I sent you about Ilona and the wild pig?
Frans
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