Probable cause
The failure of the landing gear accumulator/regulator and the installation of the improper priority valve, which precluded the landing gear from extending and locking into place.
NTSB analysis
Upon arrival over the destination airport during a positioning flight, the pilot attempted to extend the airplane's landing gear. Only the nose gear and the left main landing gear locked in the down position. The pilot reported that he performed the emergency gear extension procedure specified in the airplane's flight manual, but the right main gear did not lock down. The pilot returned to the departure airport and landed. During rollout, the right main landing gear collapsed and the airplane slid off the runway resulting in substantial airframe damage. An examination of the airplane revealed that an accumulator/regulator in the extension system had malfunctioned. In addition, an incorrect priority valve was installed and precluded the gear from locking down.
Text from the NTSB. Open the NTSB docket for WPR10LA034 for the full record.
Event
- Date
- Oct 21, 2009
- Type
- Accident
- Place
- Cedar City, Utah
- Nearest airport
- Cedar City Regional (CDC)
- Highest injury
- None
- Weather
- Visual (VMC)
- Light
- Day
Aero Commander 690
- N-number
- N690TR
- Category
- Airplane
- Damage
- Substantial
- Operating rule
- Part 91 (general aviation)
- Purpose of flight
- Positioning
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.