Family says "unexpected wind shear" caused fatal Colorado plane crash

Officials have released new details of their investigation into a small plane crash that killed two men in Erie, Colorado, a crash that family members say was caused by sudden wind shear.

The Erie Police Department said that the plane went down just east of the runway at the Erie Municipal Airport on the afternoon of Oct. 19. Both people aboard the ultralight VL-3 aircraft, Niles Tilenius of San Mateo County, Cali. and William Johnston of Hillsborough County, Fla., were killed.

The FAA and the National Transportation Safety Board launched an investigation into the crash and released the preliminary results on Monday.

According to the NTSB, multiple people witnessed the airplane approaching runway 34, but it didn't land. Instead, they say it leveled off and then started to climb in a go-around maneuver. But witnesses at the airport and in the surrounding area say that's when the airplane flipped and then spun to the ground.

Investigators say surveillance camera footage showed the airplane in a nose-low spin before impact.

The crash crushed the landing gear and the forward fuselage of the aircraft, the empennage separated from the fuselage, and both wings partially separated at the wing root, said the NTSB. They reported that the GRS Rescue system, an airframe parachute, did not deploy.

Tilenius's family said he was an experienced flight instructor working with Odyssey Pilot Hours in Erie and was piloting the aircraft with his student, Johnston, at the time of the crash. In his obituary, his family said the crash was caused by "fierce, sudden, unexpected wind shear overwhelming their small plane close to the runway."