CEN12FA164 · Piper PA-24-250
Piper PA-24-250 · Accident: flight instrument malfunction/failure en route
From Abilene Regional Airport (ABI) to University of Oklahoma Westheimer Airport (OUN)
Narrative check · The NTSB narrative appears to contradict this record's date. Values are shown as recorded, not corrected; compare with the narrative.
Event
- NTSB case
- CEN12FA164
- 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
- 2 · 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
Piper PA-24-250
- Aircraft type
- Piper PA-24
- 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
- N7147P
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Abilene Regional Airport (ABI), Abilene, TXTo University of Oklahoma Westheimer Airport (OUN), Norman, OK
- Aircraft age
- About 52 years (built 1960)
- 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
- En route · cruise
- 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
- Flight instrument malfunction/failure
- 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 oper/perf/capability
- Aircraft › Aircraft systems
- Personnel issues › Action/decision
- Personnel issues › Physical
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
After leveling at a cruise altitude of 9,500 feet mean sea level the pilot reported that he had lost instrument suction and his attitude indicator. Radar data showed that the airplane made a climbing right turn and then descended rapidly. Radar and radio contact were lost and the wreckage was found the next morning. Ground and airplane impact signatures showed evidence of a nearly vertical nose down collision with terrain. Other pilots in the area reported a reduction in visibility with blowing dust, which severely restricted visibility and resulted in the loss of a visible horizon. The manufacturer of the vacuum pump had issued a service letter 4 years earlier that indicated that the pump was beyond its mandatory replacement time and must be removed from service. A postaccident examination revealed that the vacuum pump had a preimpact failure that resulted in the loss of all vacuum driven flight instruments.
It is likely that the pilot inadvertently encountered instrument meteorological conditions (IMC) with reduced visibility and the lack of a visible horizon. The airplane's subsequent turning ground track and rapid, near-vertical descent are consistent with the pilot's loss of control of the airplane because of spatial disorientation following the loss of flight instrumentation while flying at night without a discernable horizon.
According to FAA Advisory Circular 60-4A "Pilot's Spatial Disorientation," "Surface references and the natural horizon may at times become obscured, although visibility may be above visual flight rule minimums. Lack of natural horizon or surface reference is common on over-water flights, at night, and especially at night in extremely sparsely populated areas or in low visibility conditions. A sloping cloud formation, an obscured horizon, a dark scene spread with ground lights and stars, and certain geometric patterns of ground lights can provide inaccurate visual information for aligning the aircraft correctly with the actual horizon. The disoriented pilot may place the aircraft in a dangerous attitude."
Probable cause
The loss of flight instrumentation due to a failed vacuum pump while flying a night without a discernable horizon, which resulted in the pilot's spatial disorientation and an in-flight loss of control and impact with terrain. Contributing was the continued operation of the airplane with a recalled and unsafe vacuum pump.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN12FA164
- Event ID
- 20120215X93423
- Case number
- CEN12FA164
- 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: local date, investigation status. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2012-02-21.
- API snapshot SHA-256: 838ab9a79ac59a00bca2bd74b063c45526d86e20582a923c47c1ab2e6c26c5bc; retrieved 2026-09-13T22:11:15.397Z.