Riga Higher Military Aviation Engineering College (ВВАИУ) named after Yacob Alksnis was a higher educational institution of the USSR Air Force, in which from 1967 to 1993 the engineering and scientific personnel of the USSR Air Force were trained. Located in Riga (Latvian SSR). Disbanded in connection with the collapse of the USSR. More info on the college is available here. 
 
Though the college had several names, it was officially established in 1938, and in 1988 celebrated its 50 year anniversary. This badge commemorates that anniversary. Beautiful bright enamel, working screwback on the reverse. Very fine.