Avengers Quinjet

Quinjet

Quinjet

Built by Stark International, and armed with weapons and energy force shields, the Avengers' Quinjets can achieve a top speed of MACH 8, and are capable of submersible and space travel.

There was an advanced "superfast" prototype that was destroyed in Arctic, unable to handle severe weather conditions.  It has a projected stop speed of MACH 10, and had a design which looked like it was based on the SR-71 "Blackbird.