# NTSB FTW94LA089: Mooney M20J, N201SX, Gallup, NM, February 24, 1994

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: February 24, 1994, 09:42 local (16:42 UTC)
- Place: Gallup, NM
- Coordinates: 35.380935, -108.799423 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=35.3809&lon=-108.7994&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report February 14, 1995
- Report: Approved by Office Director
- NTSB case key (mKey): 19005
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW94LA089
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/19005/pdf
- Page: https://openairdocs.org/ntsb/FTW94LA089

## Probable cause

THE LOSS OF ENGINE POWER DUE TO THE FAILURE OF THE NUMBER 3 EXHAUST VALVE. A FACTOR WAS THE LACK OF SUITABLE TERRAIN AVAILABLE TO EXECUTE THE FORCED LANDING.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of engine power(total) - mech failure/malf, cruise
  - engine assembly,valve,exhaust - failure,total (cause)
- Forced landing, descent - emergency
- On ground/water collision with object, landing - roll
  - terrain condition - snow covered
  - terrain condition - hidden obstruction(s)
  - terrain condition - none suitable (contributing factor)

## Analysis

AT 8,500 FEET MSL THE PILOT EXPERIENCED A LOSS OF ENGINE POWER DUE TO THE FAILURE OF THE EXHAUST VALVE FOR THE NUMBER THREE CYLINDER. THE PILOT ATTEMPTED A FORCED LANDING TO A SNOW COVERED OPEN FIELD. DURING THE LANDING ROLL, THE RIGHT MAIN LANDING GEAR COLLAPSED AFTER IMPACTING A TREE STUMP.

## Factual narrative

On February 24, 1994 at 0942 mountain standard time, a Mooney M20J, N201SX, was substantially damaged during a forced landing near Gallup, New Mexico.  The private pilot was not injured.  Visual meteorological conditions prevailed for the personal flight.

The pilot stated in the enclosed pilot/operator report that while in cruise flight at 8,500 feet MSL, he heard a "pop-like" sound coming from the engine, immediately followed by a severe engine vibration.  The pilot added that the engine lost power and he proceeded to shut down the engine.

A forced landing to a snow covered open field was performed. The pilot elected to land with the landing gear extended.  During the landing roll the right main landing gear collapsed after it collided with tree stump.

Post accident examination of the engine revealed that the exhaust valve for the number 3 cylinder failed, resulting in the total loss of engine power.

## Aircraft

- Registration: [N201SX](https://openairdocs.org/deregistered/N201SX-2018-03-08), registration cancelled 2018-03-08, S/N 24-0308, built 1977 (OpenAirDocs)
- Reported make and model: MOONEY M20J
- Registry model: [Mooney M20J](https://openairdocs.org/model/mooney-m20j) (registry code 5870219) (OpenAirDocs)
- Category: Airplane
- Serial number: 24-0308
- Airframe hours: 1619
- Engines: LYCOMING IO-360-AIB6D 200 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Smith, Gerald A.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, April 5, 1993, 131 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 42; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 783 total, 112 in this make and model, 715 as pilot in command

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 60 statute miles
- Lowest ceiling: none
- Temperature: 19 °F, dew point 12 °F
- Altimeter: 30.00 inHg
- Observed at: GUP

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19940224002879A](https://openairdocs.org/incident/19940224002879A), Feb 24, 1994: Mooney M20J, Gallup, NM, Substantial damage. Lost power en route. Landed in snow covered field. Struck stump. NR3 cylinder exhaust valve failed.

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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