# NTSB LAX98LA162: Schweizer G164D, N8177K, Richvale, CA, May 17, 1998

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: May 17, 1998, 11:30 local (18:30 UTC)
- Place: Richvale, CA
- Coordinates: 39.479232, -121.83966 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=39.4792&lon=-121.8397&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report February 11, 2000
- Report: Approved by Office Director
- NTSB case key (mKey): 30088
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX98LA162
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/30088/pdf
- Page: https://openairdocs.org/ntsb/LAX98LA162

## Probable cause

The separation of four compressor/turbine blades resulting in a sudden loss of engine power with a subsequent forced landing into unsuitable terrain.

## 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, takeoff - initial climb
  - compressor assembly,blade - failure (cause)
  - misc,engine compressor stall/surge (contributing factor)
- Forced landing, emergency descent/landing
- Nose over, emergency landing after takeoff
  - terrain condition - soft (contributing factor)

## Analysis

On takeoff, the pilot experienced a loss of engine power preceded by the sound of loud 'pop.'  He completed a forced landing on soft ground and the aircraft nosed over.  During the post-accident teardown inspection of the engine, it was noted that four compressor/turbine blades had failed at the blade/butt interface.  The failed blades were not standard manufacturer's replacement parts.

## Factual narrative

On May 17, 1998, at 1130 hours Pacific daylight time, a Schweizer G164D, N8177K, was destroyed when it nosed over during a forced landing following a total loss of engine power on takeoff.  The commercial pilot was not injured and there was no property damage.  At the time of the accident, the flight was departing the Doc Thompson airstrip which is located 9 miles north-northwest of Richvale, California.  Visual meteorological conditions prevailed and no flight plan was filed for the 14 CFR Part 137 agricultural application flight.

The operator stated in his accident report that, approximately 15 feet agl, he heard a loud "pop" in the engine compartment followed by an immediate loss of engine power.  He made a forced landing to a soft dirt field about 800 feet from the end of the runway.

During a teardown inspection of the engine, it was noted that four compressor/turbine blades were broken off at the blade/butt interface.  The parting surface on the butt side of the break was clean and did not show evidence of progressive failure.  It was also noted that the four broken blades were not standard manufacturer's replacement parts.

## Aircraft

- Registration: [N8177K](https://openairdocs.org/deregistered/N8177K-1998-08-10), registration cancelled 1998-08-10, S/N 8D (OpenAirDocs)
- Reported make and model: Schweizer G164D
- Registry model: [Gulfstream-Schweizer A/C GULFSTREAM AM G-164D](https://openairdocs.org/model/gulfstream-schweizer-a-c-gulfstream-am-g-164d) (registry code 3979908) (OpenAirDocs)
- Category: Airplane
- Serial number: 8D
- Airframe hours: 9628
- Engines: P&W PT6A-34AG 750 horsepower turbo prop
- Damage: Destroyed
- Flight: Aerial application, Part 137
- Registered owner: Avag, Incorporated
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, April 25, 1998, 62 hours before
- Departed: PVT, CA
- Airport: Thompson Strip, runway 16, 2,000 × 30 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 57; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: front; flight hours: 37,000 total, 8,000 in this make and model, 50 in the last 90 days, 50 in the last 30 days, 8 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 280° at 8 knots
- Visibility: 60 statute miles
- Lowest ceiling: none
- Temperature: 70 °F, dew point 46 °F
- Altimeter: 30.00 inHg
- Observed at: CIC, 18 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 19980517009779A](https://openairdocs.org/incident/19980517009779A), May 17, 1998: Scwzer G164D, Richvale, CA, Destroyed. On takeoff, the pilot experienced a loss of engine power and completed a forced landing on soft ground and the aircraft nosed over. During the post accident…

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.