FACTUAL REPORT: FLAP SETTINGS EYED IN MU-2 CRASH
Mitsubishi MU-2B-60, Elyria, Ohio, Jan 18, 2010–The turboprop twin was destroyed and its ATP-rated pilot and three passengers were killed when it crashed on approach to Lorain County Regional Airport. The Part 91 flight departed Gainesville Regional Airport in Florida. After a missed approach, ATC cleared the aircraft for landing on Runway 7. According to radar track data, the MU-2 began drifting left of centerline when it was about 1,400 feet msl and continued in that direction until the last radar return, which showed it approximately 1,000 feet left of the runway centerline. A witness who was waiting to greet the flight reported seeing the airplane emerge from the clouds in a nose-low attitude, rolling to the right with the wings almost perpendicular to the ground. The turboprop then disappeared in a cloud of snow disturbed by the impact.
A National Weather Service report indicated a 70- to 80-percent chance of icing below 3,000 feet for the vicinity at the time of the accident. A review of the aircraft’s records showed that the MU-2 was in compliance with AD 2000-09-15, which required the installation of a deice monitoring system, an automatic autopilot disconnect system and a trim-in-motion alert system to help prevent departure from controlled flight in icing conditions. The radar track of the airplane showed a calibrated airspeed of approximately 130 knots on the approach, decreasing to less than 100 knots during the 20 seconds before radar contact was lost. Examination of the wreckage revealed that the flaps were set at five degrees at the time of the accident. The before-landing checklist states that the aircraft’s flaps are to be set to 20 degrees (below 155 kcas) or 40 degrees (below 120 kcas). While the aircraft’s flight manual contains performance charts for landing approach speed for both of those settings, it does not contain a chart for landing approach speeds using 5 degrees of flap.