How high do cicadas fly?

Here's an answer based on second-hand information.  My niece Becky's
visited Memorial Day weekend with her brother Ben, a flight instructor
in West Virginia.  Becky gave her stories about 17-year cicadas in
Greenbelt, Maryland, and Ben observed that when the 13-year cicadas were
active a few years ago in West Virginia, pilots in small planes found
that they were hitting 13-year cidadas at 5000 feet.

Carolyn Sturtevant
Greenbelt, Maryland