Air show spectators have been enjoying the Super Salto jet-powered sailplane since 2008, when the aerobatic aircraft first appeared on the circuit. Now, its manufacturer Desert Aerospace of Albuquerque, New Mexico, is marketing a two-seat sport version known as the BonusJet. Flight testing has been completed on the 56-foot-wingspan derivative of the Czech-designed Bonus sailplane. It's powered by the tiny PBS TJ-100 jet engine, also of Czech extraction. The engine retracts into the fuselage once the BonusJet arrives at altitude, but can be re-extended and restarted in flight. One of the biggest advantages, according to test pilot Bob Carleton, is the smooth operation of the little jet, when compared with the vibration of small piston engines sometimes used in self-launch motorgliders. Desert Aerospace said it also plans to develop a kit version of an "extreme light jet (XLJ)."