N21816

On April 10, 2005, at 1330 central daylight time, a Mooney M20M, N21816, sustained substantial damage during recovery from a loss of control when the airplane encountered severe turbulence at 16,000 feet mean sea level (msl) and recovered at 6,000 feet msl before executing a precautionary landing at Lincoln Airport (LNK), Lincoln, Nebraska. The commercial pilot was not injured. The 14 CFR Part 91 business flight departed Columbia, Missouri, on an instrument flight rules (IFR) flight plan at 1130, and was en route to Scottsbluff, Nebraska, to refuel before proceeding to Portland, Oregon, the final destination. Instrument meteorological conditions (IMC) prevailed at the time of the encounter with turbulence.

The pilot reported that a thorough pre-flight weather briefing was obtained from the Columbia, Missouri, Flight Service Station (FSS). Due to severe weather reported in Kansas and Colorado, the pilot filed a route of flight that was further north through Nebraska.

The pilot reported, "While in level cruise flight in IMC at 16,000' I suddenly encountered an unanticipated severe downdraft that caused a temporary loss of control of the aircraft. The plane was suddenly in a rapidly descending spiral. I was able to regain control and level off at 6,000' in VMC. After re-establishing contact with Minneapolis Center I diverted to Lincoln, NE (KLNK), the nearest suitable airport." The pilot also reported, "The approach and landing were uneventful. Gear-down indications were normal. However, when turning off Runway 18 onto the taxiway the right main gear collapsed."

A Federal Aviation Administration inspector examined the airplane. The inspection revealed that the right landing gear had collapsed, the wing spar was bent, and the wings were wrinkled. The pilot reported to the inspector that the landing gear circuit breaker had popped after the recovery from the encounter with turbulence.

A Mooney Airplane Company representative reported that the damage to the airplane indicated that the airplane experienced about 12g's of force during the recovery from the turbulence event.

The pilot reported that the storm scope on the airplane was very reliable and that it did not indicate any severe weather at the time of the upset. The storm scope was tested by a repair facility after the accident and it performed within normal specifications.

The Columbia FSS reported that no pilot reports (PIREPS) along the pilot's route of flight were available at the time of the weather brief. The reported severe weather was located over Kansas at the time of the brief.

A review of the air traffic control (ATC) tapes from Minneapolis Center revealed that the ATC controller and the pilot did not have any communications about turbulence or severe weather prior to the upset occurring.