WPR10LA034 · Aero Commander 690
Kolob Canyons Air Services L L C Aero Commander 690 · Accident: system/component malfunction/failure (non-power) on approach
From Cedar City Regional Airport (CDC) to an unrecorded destination
Event
- NTSB case
- WPR10LA034
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Aero Commander 690
- Aircraft type
- Aero Commander 690
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N690TR
- Operator
- Kolob Canyons Air Services L L C
- Onboard fatalities
- Unknown
- Route
- From Cedar City Regional Airport (CDC), Cedar City, UTTo not recorded
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Approach
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- System/component malfunction/failure (non-power)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Aircraft › Aircraft handling/service
- Aircraft › Aircraft systems
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
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.
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.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR10LA034
- Event ID
- 20091029X63056
- Case number
- WPR10LA034
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 46f3106b0fbccda18c891df70559902f063d882f19da9f68cc9f9c8313e4db86; retrieved 2026-09-15T13:27:03.674Z.