Who was the head coach for the Baltimore Colts when John Elway was drafted?

Frank Kush.

Kush was head coach of the Colts between 1982-1984, their last two seasons in Baltimore and first season in Indianapolis, and had an overall record of 11-28-1. He resigned with one game remaining in the 1984 season.

Elway was the #1 overall selection by the Colts in the 1983 NFL Draft.