 The longest single Phoenix launch was successful against a target at a range of in April 1973.Another unusual test was made on 22 November 1973, when six missiles were fired within 38 seconds at Mach 0.78 and ; four scored direct hits.With time, the early versions of all the missiles were replaced by more advanced versions, especially with the move to full solid-state electronics that allowed better reliability, better ECCM and more space for the rocket engine.