Question to the Ministry of Defence:

To ask the Secretary of State for Defence, what assessment he has made of the suitability of the F-35 Lightening II for long periods of supersonic flight.

When required, the Lightning can cruise at supersonic speed for long periods. However operationally, like most modern combat fast jets, supersonic speeds would only be used in limited tactical situations and would only be required for short bursts; the vast majority of its tactical employment is predicated around subsonic operating speeds. As a result, it is highly unlikely that Lightning would need to be routinely flown at supersonic speed for sustained periods.