This is the issue where Flash Lightning became Lash Lightning. No explanation...it just was.
It is also a story with inconsistencies which seem jarring. Lash drives a car to the Army base. But he can fly and uses that power when he is blocked from entering in his car. Why drive? To show that the road to the base is blocked appears to be the only reason. And the evil Mastermind, who can “project himself anywhere” can project himself on the base, but then climbs into the commanding officer’s window the old-fashioned way.
Despite those weaknesses in the writing, the art is by comics journeyman Jim Mooney, and it is excellent.
From Lightning Comics Vol 2 No.1 (1941):
The origin story of Flash Lightning from Sure-Fire Comics #1 is here. Just click on the thumbnail: