# NTSB DEN90LA164: Mooney M20F, N6456Q, Torrington, WY, July 14, 1990

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 14, 1990, 14:30 local (20:30 UTC)
- Place: Torrington, WY
- Coordinates: 42.06097, -104.179985 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=42.0610&lon=-104.1800&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report November 9, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 17974
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN90LA164
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/17974/pdf
- Page: https://openairdocs.org/ntsb/DEN90LA164

## Probable cause

A PARTIAL LOSS OF POWER DUE TO A FAILED EXHAUST VALVE. A FACTOR WAS THE LACK OF SUITABLE TERRAIN FOR THE FORCED LANDING.

## Sequence of events

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

- Loss of engine power(partial) - mech failure/malf, takeoff - initial climb
  - engine assembly,valve,exhaust - failure,total (cause)
- Forced landing, descent - emergency
  - terrain condition - none suitable (contributing factor)
- In flight collision with terrain/water, maneuvering - turn to landing area (emergency)

## Analysis

THE PRIVATE PILOT TOOK OFF AND ATTEMPTED TO CLIMB. HE SAID THE ENGINE SEEMED TO BE PRODUCING ONLY PARTIAL POWER. HE TURNED BACK TO THE RUNWAY, BUT LOST ALTITUDE, DRAGGED ONE WING ON THE TERRAIN, AND LANDED ACROSS THE 75 FOOT WIDE RUNWAY. THE PLANE CROSSED THE RUNWAY, A TAXIWAY, SKIDDED UP A HILL AND CAME TO REST. THE FUSELAGE, BOTH WINGS, THE NOSE GEAR AND LEFT MAIN GEAR WERE DAMAGED. A POSTACCIDENT INVESTIGATION REVEALED A BROKEN EXHAUST VALVE IN THE NUMBER ONE CYLINDER.

## Aircraft

- Registration: [N6456Q](https://openairdocs.org/aircraft/N6456Q), registered now, S/N 670535, built 1967 (OpenAirDocs)
- Reported make and model: MOONEY M20F
- Registry model: [Mooney M20F](https://openairdocs.org/model/mooney-m20f) (registry code 5870214) (OpenAirDocs)
- Registry engine: [Lycoming I0360 series](https://openairdocs.org/engine/lycoming-i0360-series) (registry code 41515, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 670535
- Airframe hours: 5740
- Engines: LYCOMING IO-360-A1A 200 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: B & L Aviation, Inc.
- Departed: TOR
- Destination: RAP, RAPID CITY, SD
- Flight plan: VFR
- Airport: TOR, Torrington, runway 1, 5,700 × 75 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 37; private; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; flight hours: 1,500 total, 1,000 in this make and model, 1,440 as pilot in command, 51 in the last 90 days, 33 in the last 30 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 20 statute miles
- Lowest ceiling: none
- Temperature: -0 °F, dew point -0 °F

## 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 19900714025789A](https://openairdocs.org/incident/19900714025789A), Jul 14, 1990: Mooney M20F, Torrington, WY, Substantial damage. Partial power loss on climbout. Dragged a wing landing across runway gear up. Broken exhaust valve NR1 cylinder.

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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