# NTSB LAX90DVG02: Schweizer G-164B, N6977K, Knights Landing, CA, November 18, 1989

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Final report
- Date: November 18, 1989, 10:00 local (17:00 UTC)
- Place: Knights Landing, CA
- Coordinates: 38.889865, -121.799896 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=38.8899&lon=-121.7999&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report July 22, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 26570
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX90DVG02
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/26570/pdf
- Page: https://openairdocs.org/ntsb/LAX90DVG02

## Probable cause

THE FAILURE OF THE RIGHT MAIN LANDING GEAR DUE TO A SHEARED BOLT THAT ATTACHED THE SPRING LEG TO THE GEAR.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Main gear collapsed, landing - roll
  - landing gear,main gear spring - collapsed (cause)
  - landing gear,main gear spring - sheared (cause)

## Analysis

A RESTRICTED CATEGORY AIRCRAFT EXPERIENCED A COLLAPSE OF THE MAIN LANDING GEAR DURING THE LANDING ROLL. EXAMINATION OF ONE OF TWO AN9-92A BOLTS REVEALED IT HAD A SHEARED HEAD. THESE BOLTS ATTACH THE RIGHT MAIN LANDING GEAR SPRING LEG.

## Aircraft

- Registration: [N6977K](https://openairdocs.org/deregistered/N6977K-2018-01-23), registration cancelled 2018-01-23, S/N 532B, built 1979 (OpenAirDocs)
- Reported make and model: SCHWEIZER G-164B
- Registry model: [Grumman Acft ENG Cor-Schweizer G-164B](https://openairdocs.org/model/grumman-acft-eng-cor-schweizer-g-164b) (registry code 3952802) (OpenAirDocs)
- Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 532B
- Airframe hours: 5120
- Engines: P&W R-1340-AN1 600 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Registered owner: Wagner Aviation
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: 100 hour, October 1, 1989, 47 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 53; commercial; airplane ratings: multi-engine land, single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: center; flight hours: 20,000 total, 1,500 in this make and model, 20,000 as pilot in command, 125 in the last 90 days, 75 in the last 30 days, 6 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 4 statute miles
- Lowest ceiling: none
- Temperature: 61 °F, dew point 48 °F
- Altimeter: 29.00 inHg

## 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 19891118046369A](https://openairdocs.org/incident/19891118046369A), Nov 18, 1989: Scwzer G164B, Knights Landing, CA, Substantial damage. Right main gear broke off on Landing roll. Two attach bolts AN992A had sheared.

## Other investigations on N6977K (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 LAX81FVG41](https://openairdocs.org/ntsb/LAX81FVG41), Jun 5, 1981: Grumman G-164 (N6977K), Davis, CA, substantial damage

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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