A nice, short article describing the beauty and dangers of flying over mountains in winter. It emphasises that despite the fascinating views, caution is advised as flying over high mountains, especially ridges, carries many risks. An old aviation wisdom says that the mountains are "higher" in winter, which is due to the denser cold air that affects the pressure surfaces and thus the altitude measurement in the aircraft. The altitude can vary by four per cent per 10° from the standard temperature, depending on the temperature deviation.
Specific precautions are recommended for flying in the mountains, such as avoiding flights over closed cloud cover, maintaining a safety altitude of at least 1000 ft AGL when crossing passes, avoiding climbs when passing passes and adapting to strong vertical air currents. Inexperienced pilots in particular should refrain from crossing the Alps under certain conditions (e.g. foehn, thunderstorms, showers). It is also recommended to file an ATC flight plan and to carry a portable emergency transmitter.
Source references:
StaySafe Aero
