# NTSB BFO93LA142: North American AT-6, N6617X, Matawan, NJ, July 30, 1993

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 30, 1993, 12:45 local (16:45 UTC)
- Place: Matawan, NJ
- Location: 40.4110° N, 74.2365° W: Placed by OpenAirDocs: center of Matawan, NJ, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=40.4110&lon=-74.2365&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report December 3, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 11958
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=BFO93LA142
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/11958/pdf
- Page: https://openairdocs.org/ntsb/BFO93LA142

## Probable cause

THE WATER COLLECTION IN THE IGNITION HARNESS WHICH RENDERED THE LOWER CYLINDER SPARK PLUGS INOPERATIVE RESULTING IN PARTIAL POWER LOSS.

## 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
  - ignition system,ignition harness - contamination (cause)
  - ignition system,spark plug - inoperative (cause)
- Forced landing, descent - emergency
- Overrun, landing - roll

## Analysis

SHORTLY AFTER TAKEOFF, THE AIRPLANE'S ENGINE LOST PARTIAL POWER.  THE PILOT STATED HE MADE A 180 DEGREE TURN BACK TOWARDS THE DEPARTURE RUNWAY. THE PILOT STATED THAT BECAUSE OF THE AIRPLANE'S AIRSPEED AND THE TAILWIND, HE ELECTED TO LAND PARALLEL TO THE RUNWAY ON THE GRASS. THE PILOT STATED THAT THE AIRPLANE WAS NOT GOING TO STOP PRIOR TO IMPACTING TREES LOCATED AT THE END OF THE GRASS SO HE GROUND LOOPED THE AIRPLANE. DURING THE GROUND LOOP, THE AIRPLANE'S LEFT WING CONTACTED THE GROUND DAMAGING THE SPAR AND LANDING GEAR. POST ACCIDENT EXAMINATION OF THE ENGINE REVEALED THAT THERE WAS WATER IN THE FRONT AND REAR IGNITION HARNESSES RENDERING THE NUMBER 4, 5, 6, AND 7 CYLINDER SPARK PLUGS INOPERATIVE.

## Aircraft

- Registration: [N6617X](https://openairdocs.org/aircraft/N6617X), registered now, S/N 7718-59, built 1944 (OpenAirDocs)
- Reported make and model: NORTH AMERICAN AT-6
- Registry model: [North American AT-6](https://openairdocs.org/model/north-american-at-6) (registry code 6400402) (OpenAirDocs)
- Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 7718-59
- Airframe hours: 4625
- Engines: P&W R-1340 AN-1 600 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Bi-Plane Adventure Tours Inc.
- Registered owner: Edward Del Rosso
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, June 14, 1993, 39 hours before
- Departed: 2N8
- Destination: N51, SOLBERG, NJ
- Airport: 2N8, Marlboro Airport, runway 9, 1,500 × 50 ft, grass/turf

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 49; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: front; flight hours: 5,210 total, 119 in this make and model, 5,154 as pilot in command, 165 in the last 90 days, 45 in the last 30 days, 5 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 280° at 9 knots
- Visibility: 25 statute miles
- Lowest ceiling: none
- Temperature: 86 °F, dew point 61 °F
- Altimeter: 29.00 inHg
- Observed at: ACY, 1 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 19930730027159A](https://openairdocs.org/incident/19930730027159A), Jul 30, 1993: Namer AT6, Matawan, NY, Substantial damage. Engine lost partial power on climb. Returned. Chose grass parallel runway. Ground looped. Water in ignition harness

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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