# NTSB CHI93DTG03: Piper PA-25-235, N4693Y, Washburn, ND, August 20, 1993

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Final report
- Date: August 20, 1993, 08:15 local (13:15 UTC)
- Place: Washburn, ND
- Coordinates: 47.289112, -101.020622 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=47.2891&lon=-101.0206&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report August 17, 1994
- Report: Approved by Office Director
- NTSB case key (mKey): 9149
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI93DTG03
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/9149/pdf
- Page: https://openairdocs.org/ntsb/CHI93DTG03

## Probable cause

the loss of engine power due to a magneto failure.

## 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, maneuvering - aerial application
  - ignition system,magneto - failure,total (cause)
- Forced landing, descent - emergency
- On ground/water collision with object, landing - roll
  - object - fence post

## Analysis

The pilot was maneuvering to make a spray run on an aerial application flight when the airplane lost all engine power. The pilot made a forced landing in the field, and struck two fence posts during landing roll.  The engine examination revealed the impulse coupling flyweight in the left magneto had jammed and seized the magneto.  The magneto drive gear and the camshaft gear were stripped.

## Factual narrative

On August 20, 1993, at 0815 central daylight time, a Piper PA-25-235, N4693Y, operated by Central Flying Service, Inc., Washburn, North Dakota, sustained substantial damage when it struck two fence posts during landing roll following a forced landing near Washburn.  The commercial pilot was not injured. No flight plan was filed for the aerial application flight.  Visual meteorological conditions prevailed at the time of the mishap.

The pilot reported he was maneuvering to commence an application run when the engine lost all power.  He made a landing in the field, but struck two fence posts during landing roll.

The engine examination revealed the left magneto impulse coupling flyweight was jammed, and the magneto was seized.  The impulse coupling was failed, and the magneto drive gear, and camshaft gears were damaged.

## Aircraft

- Registration: [N4693Y](https://openairdocs.org/aircraft/N4693Y), registered now, S/N 25-4424, built 1967 (OpenAirDocs)
- Reported make and model: PIPER PA-25-235
- Registry model: [Piper PA-25-235](https://openairdocs.org/model/piper-pa-25-235) (registry code 7102504) (OpenAirDocs)
- Registry engine: [Lycoming 0-540 series](https://openairdocs.org/engine/lycoming-0-540-series) (registry code 41532, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 25-4424
- Engines: LYCOMING O-540-B2C5 235 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Registered owner: Central Flying Service, Inc.
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, May 11, 1993, 128 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 52; flight instructor, commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: center; flight hours: 9,300 total, 325 in this make and model, 9,200 as pilot in command, 225 in the last 90 days, 30 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 90° at 5 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 54 °F, dew point 36 °F
- Altimeter: 30.00 inHg
- Observed at: GFK, 40 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 19930820030079A](https://openairdocs.org/incident/19930820030079A), Aug 20, 1993: Piper PA25235, Washburn, ND, Substantial damage. Lost power during a spray run. On landing struck fence posts. Left magneto impulse coupling failed. Bad right mag.

## Other investigations on N4693Y (1)

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.

- [NTSB CHI06LA223](https://openairdocs.org/ntsb/CHI06LA223), Aug 3, 2006: Piper PA-25-235 (N4693Y), Underwood, ND, substantial damage, 1 fatal. Probable cause: The pilot's failure to maintain clearance with the power line during the aerial application flight.

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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