Flying the Alps is an unforgettable experience, but some extra precautions are required to make it enjoyable, and remain on the safe side. The golden rule is easy: get well trained ! A good safety margin requires specific knowledge at briefing time, and good technique in flight. If you have no experience as pilot in a mountainous area, hire a local instructor – there are things you can’t learn by yourself. That being said, here are my tips, and please don’t forget what I said in this serie’s first post about respect.

The obvious dangers in the Alps are high terrain, and clouds. One significant change for VFR pilots is the absence of natural horizon. You’ll fly below mountain tops, which can be impressive to some, and there will be few visual references to help maintaining your wings level. If weather permits, you should fly on the right hand-side of valleys, to avoid opposite traffics. How close to the mountain ? Evaluating distance to a cliff a hard task, and any error can be fatal. If your guts says you’re too close, you’re too close. This is also something to train.

Turning back in a narrow valley can be impossible if you stay too far away. If you really have to do that, prefer a right turn. Being in the left seat, you’ll get a better view on the left side, helping to manage the turn. And have a look at your attitude indicator, to make sure your bank angle is not excessive, and that you’re not loosing altitude. And remember what you learned about speed: slower turn have smaller radius, for the same bank angle. But if you really need a steep turn, make it as quick as possible, with the higher possible bank angle. But don’t by shy then. Increasing your speed and not making a steep turn will only increase the radius.

When crossing a pass, don’t simply overfly it, except if you have extra-huge spare altitude. It’s way better to fly accros at 45 degrees. This will give you better visibility of the weather on the other side, and if you have to turn back, you’ll already be well positioned. Don’t forget that the side under the wind is possibly turbulent. Keep your speed below Va to avoid overstressing your airframe.

As a VFR pilot, you’re not allowed to enter clouds. In normal areas, you risk to get disoriented, and will be unable to maintain separation with other aircraft if you go IMC. In mountains, you can also encounter a different kind of cloud, know as Cumulus Granitus, the one with a rock in. But I’m anyway sure that you’re not silly enough to go VFR in IMC. Never enter a valley if you see that the other end is in clouds. Common sense ? Yes, but each year pilots get trapped. They enter a valley with low ceiling, and when they realize their mistake, the space left between ground and clouds is no longer sufficient to turn around. IMC below surrounding terrain, precautionary landing in adverse area, or stall / spin turn are the options left.

Do you know the Altocumulus Lenticularis ? This cloud appears when standing mountain waves are deep and strong enough to create the required change in pressure and temperature. These clouds are easy to recognize: they look like flying saucers. Their meaning is also easy to interpret: don’t go there. The mountain waves creating them are so strong that you don’t want to be there.

Even when no Lenticularis are there, orographic turbulence can be a serious danger. My personal rule of thumb is easy: no Alps flying if wind at FL050 or FL100 is above 20 knots. At 20 knots, I seriously study the directions to know where rotors can form, and how to avoid them. Wind rotors can create downdrafts of several hudreds of feet per minute. If your aircraft can’t compensate for them, try changing valley side, to find the center of the rotor, or the updraft side. Thinking that your aircraft will be able to cope with it is simply wrong. Flying at 8′000 feet or more, the climb performance of most single engine does not exceed 5oo feet per minute. If you encounter downdrafts in the 2′000 feet per minute range, well… you’d better have lots of spare altitude.

Another invisible danger is hypoxia. Taking a single engine normally aspirated piston aircraft above 10′000 feet is usually not problematic. Most of them have service ceiling in the 13-14′000 feet range. The performance will degrade, but the engine and airframe will do it. But what about your performance ? Personally, flying at 10′000 feet is not a problem. Anything above is for short times only. I flew once at 13′500 feet for 20 minutes, and I clearly felt the symptoms. Click here to read my personal feed-back about hypoxia.

Engine and power management is also slightly different, not because of the Alps, but because of altitude. The lower air density leads to limited lift, and lower engine performance. If you don’t want your engine to quit, it’s important to adjust your mixture (unless flying with a FADEC, hehe…). This is important in cruise at any altitude, but close above 10′000 feet, the air / fuel mixture can become so rich that the engine will simply quit. Don’t forget to enrich it again when you start descent.

When planing your Alpine flight, prefer to go there in the morning. There will be less thermal turbulence, and no cumulative clouds. Finally, don’t forget that you’ll probably not be alone up there. Climb towards the Matterhorn on a sunny and windless saturday morning, and you could find yourself flying around it with three other aircraft. Remain in contact with Geneva Information or Zurich Information to know what the other are doing – even if this is Flight Information Service only, no advisory.

That bein said, flying the Alps is really a wonderful experience that you should not miss if you have an opportunity. Be well prepared, get some extra training if needed, apply the rules, and everything will go fine. Just as any unfamiliar environment, the Alps offer challenge and rewards, and you should not be afraid of flying there.

Read more:

Flying the Alps I – Personal impressions

Tips for VFR flying in Switzerland