# NTSB LAX90DVG01: Schweizer G-164B, N3633Q, Grimes, CA, November 16, 1989

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Final report
- Date: November 16, 1989, 08:45 local (16:45 UTC)
- Place: Grimes, CA
- Coordinates: 39.039829, -121.900367 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=39.0398&lon=-121.9004&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report June 30, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 26569
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX90DVG01
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/26569/pdf
- Page: https://openairdocs.org/ntsb/LAX90DVG01

## Probable cause

FAILURE OF THE COUNTER WEIGHT BRACKET TO THE PROPELLER ASSEMBLY.

## 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, maneuvering - aerial application
  - propeller system/accessories,counterweight - failure,partial (cause)
  - propeller system/accessories,counterweight - fatigue (cause)
- Forced landing, descent - emergency
- Nose over, landing

## Analysis

THE PILOT OF THE SPRAY AIRCRAFT EXECUTED AN EMERGENCY LANDING INTO A PLOWED FIELD AFTER EXPERIENCING A LOSS OF ENGINE POWER. EXAMINATION OF THE PROPELLER REVEALED A PORTION OF THE COUNTER WEIGHT BRACKET WAS MISSING. THERE WERE SEVERAL AREAS OF 'BEACH MARKS' EXTENDING FROM THE INNER RADIUS TO THE OUTER RADIUS OF THE FRACTURED AREAS.

## Aircraft

- Registration: [N3633Q](https://openairdocs.org/deregistered/N3633Q-2012-04-05), registration cancelled 2012-04-05, S/N 777B (OpenAirDocs)
- Reported make and model: Schweizer G-164B
- Registry model: [Schweizer G-164B](https://openairdocs.org/model/schweizer-g-164b) (registry code 8059055) (OpenAirDocs)
- Category: Airplane
- Serial number: 777B
- Airframe hours: 2355
- Engines: P&W R-1340-AN1 600 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Operator: Harold C. Tacker
- Registered owner: Onstott Dusters
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, March 1, 1989, 582 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 63; commercial; airplane ratings: multi-engine land, single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: center; flight hours: 20,000 total, 6,000 in this make and model, 19,500 as pilot in command, 300 in the last 90 days, 100 in the last 30 days, 10 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 25 statute miles
- Lowest ceiling: none
- Temperature: 43 °F, dew point 39 °F
- Altimeter: 30.00 inHg
- Observed at: MYV

## 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 19891116045719A](https://openairdocs.org/incident/19891116045719A), Nov 16, 1989: Scwzer G164B, Grimes, CA, Substantial damage. Engine quit on spray operation. Landed in soft field and nosed over. Propeller counterweight was missing.

## Other investigations on N3633Q (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 LAX07LA168](https://openairdocs.org/ntsb/LAX07LA168), May 13, 2007: Schweizer G-164B (N3633Q), Colusa, CA, destroyed, 1 fatal. Probable cause: The pilot's failure to maintain clearance from wires.
- [NTSB CHI95LA080](https://openairdocs.org/ntsb/CHI95LA080), Feb 3, 1995: Schweizer G-164B (N3633Q), Brule, NE, substantial damage. Probable cause: Loss of engine power due to undetermined reasons.

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.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.