Excel-Jet of Monument, Colo., is suing the FAA over the June 2006 crash of its proof-of-concept Sport-Jet, which was destroyed on takeoff from Colorado Springs Airport. According to witnesses, the single-engine composite jet rolled to the left, hit the runway and cartwheeled down the runway just after takeoff. The test pilot and flight-test engineer sustained minor injuries. The NTSB determined the probable cause to be “a loss of control for an undetermined reason during takeoff/initial climb that resulted in an in-flight collision with terrain.” According to Excel-Jet president Bob Bornhofen, the crash was caused by wake turbulence created by a Dash 8 twin turboprop that had just taken off, though the NTSB report dismisses this theory. The lawsuit claims that ATC cleared the aircraft for takeoff behind the Dash 8, “in violation of mandatory separation requirements.”