Investigators could find no mechanical reason for the deadliest Douglas County plane crash in 45 years, which occurred May 9, 2009.
A report released Friday by the National Transportation Safety Board said the Beechcraft BE 95 crashed after pilot, 58-year-old aviation businessman Gary Annas, pulled up suddenly after flying over Carson Valley rooftops, made a sudden steep climbing left turn, stopped at the top of the turn and then dropped toward the ground nose first. The engines could be heard running the whole time.
In addition to Annas, Paul Dallas, 43, of Minden; Leia Denner, 40, and Brent Fahey, 30, both of Gardnerville; and Beau McGrath, 30, of Kirkwood, Calif., were killed in the crash.
An examination of the wreckage revealed that both engines were working when the crash occurred and all control cables were where they were supposed to be.
Toxicology tests on Annas revealed no sign of carbon monoxide, cyanide or ethanol, confirming that he had not consumed alcohol prior to the flight. Annas did test positive for diphenhydramine, an antihistamine.
Investigators said the stall speed for the Beechcraft at a 60 degree angle of bank was 105 knots at its maximum weight.
They quoted from the Airplane Flying Handbook that the stall speed is higher "when excessive maneuvering loads are imposed by steep turns, pull-ups, or other abrupt changes in its flightpath. Stalls entered from such flight situations are called 'accelerated maneuver stalls.'"
In the report, investigators said stalls from abrupt maneuvers tend to be more rapid and severe than normal stalls, because they occur at higher speeds.
The aircraft's speed was about 120 knots during its final leg, according to data downloaded from a handheld global positioning system.
The crash occurred on the day before Mother's Day. At least four of the occupants had been at a Mottsville ranch cattle branding function. Annas offered to take them on a flight. The crash occurred within sight of the ranch.
While witnesses to the flight had different takes on the aircraft's altitude, investigators had a photo of the airplane flying over the Valley taken by a hiker in the Carson Range. The airplane's shadow is visible below it. Investigators estimate the distance between the airplane and the shadow is two to four wing spans. With a wingspan of 37 feet, that places the aircraft between 74 and 148 feet in altitude as it was flying over the Valley.
