Valkyrie: the North American XB-70: The USA's Ill-fated Supersonic Heavy Bomber

by Graham M. Simons

air inlet control system (AICS).

AICS

plenum

Ideally, the terminal shock wave would have been at the minimum throat area. But factors such as gust disturbances could ‘pop’ the shock outside the inlet, resulting in an ‘unstart’ and possible engine flameout. Engineers decided to accept a small performance penalty and move the shock wave further aft in an attempt to prevent this.

Terminal Shock Wave