Military investigators say a sticky piston in the fuel control mechanism of a Royal Canadian Air Force CF-18 was likely the root cause of a spectacular crash of the jet during rehearsal for an airshow in Lethbridge, Alberta, in July of 2010. The pilot, Capt. Brian Bews, ejected from the aircraft less than 300 feet above the ground and suffered three compressed vertebrae, but has since gone back to work. The crash was caught from multiple angles by video and still photographers. Bews was practicing the high alpha maneuver in which the aircraft flies at its lowest possible forward speed using a combination of engine power and an extreme angle of attack. To resume normal flight, the pilot applies full power and afterburner to climb out and that’s when things went wrong.
“The engine malfunction was likely the result of a stuck ratio boost piston in the right engine main fuel control that prevented the engine from advancing above flight idle when maximum afterburner was selected,” says the RCAF report. “The large thrust imbalance between the left and the right engines caused the aircraft to depart controlled flight and the aircraft was unrecoverable within the altitude available.” There was a brisk wind blowing and it pushed Bews away from the exploding wreckage but his leg tangled in the shroud lines and he wasn’t able to release the canopy when he landed. He was dragged a few hundred yards before members of the Canadian Army Skyhawks parachute team chased after him in a vehicle and were able to collapse the chute and give him first aid. The RCAF says it’s improving airshow training and modifying the engine controls to prevent a recurrence of the malfunction.