Perris Valley Aviation

De Havilland DHC-6 Twin Otter

The pilot of the twin-engine, turbine-powered airplane reported that, while providing flights for skydivers throughout the day, he had a potential new hire pilot flying with him in the right seat. He added that, on the eighth flight of the day, the new pilot was flying during the approach and "approximately 200 feet south from the threshold of [runway] 15 at approximately 15 feet AGL [above ground level] the bottom violently and unexpectedly dropped out. [He] believe[d] some kind of wind shear caused the aircraft [to] slam onto [the] runway and bounce into the air at a 45 to 60-degree bank angle to the right." The prospective pilot then said, "you got it." The pilot took control of the airplane and initiated a go-around by increasing power, which aggravated the "off runway heading." The right wing contacted the ground, the airplane exited the runway to the right and impacted a fuel truck, and the right wing separated from the airplane. The impact caused the pilot to unintentionally add max power, and the airplane, with only the left engine functioning, ground looped to the right, coming to rest nose down.

De Havilland DHC-6 Twin Otter

The ground loader had fueled the airplane from the airport fuel truck. He stated that the flight crew did not sump the fuel tanks after they were fueled. Immediately after takeoff the right engine lost power, the right wing lowered to about 90°, and the airplane impacted the ground adjacent to the runway. Then forward fuel tank, which provides fuel to the right engine, was found to contain about 8 gallons of a heavily contaminated mixture composed of water, an emulsifying agent, and bacterial growth. The fuel from the airport fuel truck and main underground tank contained the same mixture. Fuel had been transferred from the underground tank to the truck on the evening preceding the accident. The left propeller control was found seized in the feather position; left propeller blades in the near feather position. Six skydivers were injured while 16 other occupants including both pilots were killed.