# NTSB SEA93LA078: Schweizer G-164B-600, N7503L, Quincy, WA, March 18, 1993

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: March 17, 1993, 16:10 local (Mar 18, 1993, 00:10 UTC)
- Place: Quincy, WA
- Coordinates: 47.169864, -119.800117 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=47.1699&lon=-119.8001&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report October 13, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 42999
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA93LA078
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42999/pdf
- Page: https://openairdocs.org/ntsb/SEA93LA078

## Probable cause

UNSUITABLE TERRAIN ENCOUNTERED DURING A FORCED LANDING AFTER AN ENGINE CYLINDER ASSEMBLY HAD SEPARATED.  FACTORS INCLUDE A SNOWBANK.

## 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, cruise - normal
  - engine assembly,cylinder - separation (cause)
- Forced landing, descent - emergency
- Nose over, landing - roll
  - terrain condition - snowbank (contributing factor)
  - unsuitable terrain or takeoff/landing/taxi area - encountered (cause)

## Analysis

THE PILOT WAS RETURNING TO HIS AGRICULTURAL LANDING STRIP AFTER  APPLYING DRY FERTILIZER ON A FIELD.  ABOUT A MILE FROM THE RUNWAY, THE ENGINE STARTED RUNNING ROUGH.  WITHIN A HALF MILE OF THE AIRPORT, THE ENGINE ROUGHNESS WORSENED TO THE POINT OF TOTAL FAILURE.  THE AIRCRAFT WOULD NO LONGER MAINTAIN ALTITUDE, SO THE PILOT ATTEMPTED A FORCED LANDING IN AN ALFALFA FIELD ADJACENT TO THE RUNWAY.  AFTER TOUCHDOWN, THE AIRCRAFT ROLLED INTO A SNOWDRIFT AND NOSED OVER. INVESTIGATION REVEALED THAT THE NUMBER SEVEN CYLINDER HAD SEPARATED FROM THE ENGINE CRANKCASE.

## Aircraft

- Registration: [N7503L](https://openairdocs.org/aircraft/N7503L), registered now, S/N 826B (OpenAirDocs)
- Reported make and model: SCHWEIZER G-164B-600
- Registry model: [Schweizer G-164B](https://openairdocs.org/model/schweizer-g-164b) (registry code 8059055) (OpenAirDocs)
- Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 826B
- Airframe hours: 551
- Engines: P&W R-1340 600 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Operator: Stephans Flying Service
- Registered owner: Mid Continent Air Service
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, December 23, 1992, 15 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 38; commercial; airplane ratings: single-engine land; medical: class 1, valid medical--no waivers/lim.; seat: front; flight hours: 7,505 total, 7,200 in this make and model, 7,505 as pilot in command, 16 in the last 90 days, 16 in the last 30 days, 8 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Not reported
- Wind: 300° at 6 knots
- Visibility: 5 statute miles
- Lowest ceiling: 5,000 ft overcast

## 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 19930317005569A](https://openairdocs.org/incident/19930317005569A), Mar 17, 1993: Scwzer G164B, Quincy, WA, Substantial damage. Lost power returning to airport. Nosed over landing in a field in snowdrift. NR7 cylinder had come loose.

## Other investigations on N7503L (2)

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 WPR25LA158](https://openairdocs.org/ntsb/WPR25LA158), May 9, 2025: Schweizer G-164B (N7503L), Butte City, CA, substantial damage. Probable cause: The pilot’s use of engine beta prior to ensuring the tailwheel was on the ground during landing roll.
- [NTSB WPR11LA320](https://openairdocs.org/ntsb/WPR11LA320), Jul 9, 2011: Schweizer G-164B (N7503L), Yuba City, CA, substantial damage. Probable cause: High-cycle fatigue on the 1st-stage compressor blade retaining ring, which resulted in the ring’s fracture and a subsequent loss of engine power.

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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