Probable cause
The improper installation of the right aileron by maintenance personnel.
NTSB analysis
The airplane had recently undergone maintenance, which included an inspection of the ailerons requiring removal, reinstallation, and a functional check. Prior to the test flight, the pilot performed a pre-flight inspection of the airplane and a flight control free and correct check with no anomalies noted. While executing a turn at flight level 180, the right aileron departed the airplane. The airplane landed without further incident. Examination of the airplane revealed the inboard and middle airframe aileron hinge brackets were attached to the aft spar, intact, and showed no visible damage. The outboard airframe aileron hinge bracket was pulled and separated from the aft spar. The aileron was not located. Based on the condition of the hinge brackets, the evidence indicated the aileron bolts were not properly engaged in the aileron nut plates which caused the bolts to fall out and the aileron to depart the airplane.
Text from the NTSB. Open the NTSB docket for CEN11LA192 for the full record.
Event
- Date
- Feb 15, 2011
- Type
- Accident
- Place
- Des Moines, Iowa
- Highest injury
- None
- Weather
- Visual (VMC)
- Light
- Day
Beech E-90
- N-number
- N51DN
- Category
- Airplane
- Damage
- Substantial
- Operating rule
- Part 91 (general aviation)
- Purpose of flight
- Flight test
From the NTSB aviation accident database: N-registered aircraft, events since 2008, data through Oct 28, 2026. The file is published monthly, so the latest weeks are incomplete and recent records can change. The official source is the NTSB aviation investigation search. CheckAero is independent and not affiliated with the NTSB.