# NTSB ANC91LA113: Mooney M-20F, N6848V, Wood River, AK, August 2, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: August 1, 1991, 20:30 local (Aug 2, 1991, 04:30 UTC)
- Place: Wood River, AK
- Coordinates: 64.769226, -147.329025 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=64.7692&lon=-147.3290&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed, report April 27, 1993
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 5591
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC91LA113
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/5591/pdf
- Page: https://openairdocs.org/ntsb/ANC91LA113

## Probable cause

THE FAILURE OF THE NUMBER 4 CYLINDER CONNECTING ROD COP DUE TO FATIGUE.  CONTRIBUTING TO THE ACCIDENT WAS THE ROUGH SURFACE OF THE FORCED LANDING AREA.

## 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,connecting rod cap - fatigue (cause)
- Forced landing, landing - roll
  - terrain condition - rough/uneven (contributing factor)

## Analysis

THE PILOT-IN-COMMAND STATED THT DURING CRUISE FLIGHT THE PROPELLER STOPPED TURNING WITHIN SIX REVOLUTIONS WITHOUT WARNING.  HE WAS FORCED TO LAND ON A SAND BAR ON THE WOOD RIVER.  DURING THE LANDING THE NOSE GEAR AND RIGHT MAIN GEAR COLLAPSED.  EXAMINATION OF THE ENGINE REVEALED THAT THE CONNECTING ROD CAP FROM THE NUMBER 4 CONNECTING ROD HAD FAILED APPROXIMATELY 1/2 INCH FROM THE MATING SURFACE, ABEAM THE HEAD OF THE CONNECTING ROD BOLT.

## Aircraft

- Registration: [N6848V](https://openairdocs.org/aircraft/N6848V), registered now, S/N 22-1241 (OpenAirDocs)
- Reported make and model: MOONEY M-20F
- Registry model: [Mooney M20F](https://openairdocs.org/model/mooney-m20f) (registry code 5870214) (OpenAirDocs)
- Category: Airplane
- Serial number: 221
- Airframe hours: 1461
- Engines: LYCOMING IO-360AIA 200 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Griffin, Herbert L., Sr.
- Registered owner: Griffin, Herbert L., Sr.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, November 19, 1990, 2 hours before
- Departed: FAI, FAIRBANKS, AK

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 46; commercial; airplane ratings: single-engine land, single-engine sea; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 1,408 total, 400 in this make and model, 1,260 as pilot in command, 14 in the last 90 days, 6 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 60 statute miles
- Lowest ceiling: none
- Temperature: 61 °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 19910801031199A](https://openairdocs.org/incident/19910801031199A), Aug 1, 1991: Mooney M20F, Wood River, AK, Substantial damage. Engine threw a connecting rod through engine case. Landed on a sandbar collapsing landing gear. Rod cap failure.

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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