Some years ago I repaired one belonging to a Swiss air taxi company after it did an emergency landing in HHN
. They were on their way from Eindhoven, Netherland to Geneva, with all of Europe covered by a dense layer of clouds and fog when the had a complete failure of electrics above the clouds. Fortunately the pilots had a handheld VHF radio and a handheld GPS with them, so they knew their position and could call for help, but they knew that they would have a 90% chance to hit a mountain should they descend through the clouds. The mayday call got responded by an USAF
A-10 from Spangdahlem airbase, which then guided the Piper through the clouds to land in HHN
in CAT 3 conditions.