# NTSB ATL92LA052: Mooney M20C, N6748U, Charleston, SC, March 1, 1992

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: March 1, 1992, 16:14 local (21:14 UTC)
- Place: Charleston, SC
- Coordinates: 32.899402, -80.059082 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=32.8994&lon=-80.0591&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report August 13, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 8563
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL92LA052
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/8563/pdf
- Page: https://openairdocs.org/ntsb/ATL92LA052

## Probable cause

THE BLOCKED FUEL VENT.

## 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 - normal
  - fuel system,vent - blocked(total) (cause)
- Forced landing, descent - emergency
- In flight collision with object, descent - emergency
  - object - tree(s)
- In flight collision with terrain/water, descent - emergency

## Analysis

THE PILOT ATTEMPTED TO CHANGE FUEL TANKS, AFTER HE EXPERIENCED A LOSS OF ENGINE POWER. THE ENGINE REGAINED POWER FOR A SHORT PERIOD OF TIME, AND THEN LOST POWER AGAIN. THE PILOT EXECUTED AN EMERGENCY LANDING IN A GROUP OF SMALL TREES. EXAMINATION OF THE AIRCRAFT REVEALED THAT THE RIGHT WING FUEL TANK WAS EMPTY, AND THE LEFT FUEL TANK WAS APPROXIMATELY ONE FOURTH FULL. FURTHER EXAMINATION REVEALED THAT THE LEFT WING TANK FUEL VENT WAS BLOCKED BY NESTING DIRT DAUBERS, AND AIR COULD NOT BE FORCED THROUGH THE VENT.

## Aircraft

- Registration: [N6748U](https://openairdocs.org/deregistered/N6748U-2014-12-03), registration cancelled 2014-12-03, S/N 2470, built 1963 (OpenAirDocs)
- Reported make and model: MOONEY M20C
- Registry model: [Mooney M20C](https://openairdocs.org/model/mooney-m20c) (registry code 5870208) (OpenAirDocs)
- Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 2470
- Airframe hours: 4192
- Engines: LYCOMING O-360 180 horsepower reciprocating
- Damage: Substantial damage
- Flight: Business, Part 91
- Operator: Hannon, Fred W.
- Registered owner: Hannon, Fred W.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, August 8, 1991, 136 hours before
- Departed: 7NCO, BAYBORO, NC
- Destination: 8S5, MT. PLEASANT, SC

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 55; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 683 total, 660 in this make and model, 583 as pilot in command, 40 in the last 90 days, 16 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 14 knots
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 73 °F, dew point 39 °F
- Altimeter: 30.00 inHg
- Observed at: CHS, 15 nm away

## 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 19920301004869A](https://openairdocs.org/incident/19920301004869A), Mar 1, 1992: Mooney M20C, Mt Pleasant, SC, Substantial damage. Engine lost power en route. Crash landed in trees. Right fuel tank empty. Left tank vent fouled by dirt dauber.

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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