Unless you are close enough to suitable landing terrain and know where
it is located there is little use in flying higher as you can't see
where you are going to land any way, but that depends on the terrain,
visibility, and availability of nearby airports.

That depends on how low you fly during the day, doesn't it? During
the day it's generally safe to fly below the tops of nearby terrain
since you can see it. At night this is somewhat less bright.

Also, additional altitude gives more time to troubleshoot and solve a
problem with the fan. It may take longer at night just because of the
visibility issues.

Jose
--
"There are 3 secrets to the perfect landing. Unfortunately, nobody knows
what they are." - (mike).
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