# NTSB LAX91LA265: Glasair SH-2-RG, N306AT, Visalia, CA, June 18, 1991

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: June 18, 1991, 13:40 local (20:40 UTC)
- Place: Visalia, CA
- Coordinates: 36.400089, -119.379615 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=36.4001&lon=-119.3796&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 2 minor
- Status: Completed, report May 7, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27252
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX91LA265
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27252/pdf
- Page: https://openairdocs.org/ntsb/LAX91LA265

## Probable cause

TOTAL LOSS OF ENGINE POWER DUE TO THE FAILURE OF THE NUMBER 4 ENGINE EXHAUST VALVE.

## 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,valve,exhaust - failure,total (cause)
- Forced landing, descent - emergency
- In flight collision with terrain/water, descent - emergency
  - weather condition - high wind (contributing factor)
- Gear collapsed, landing - roll

## Analysis

THE CERTIFICATED PRIVATE PILOT/OWNER STATED THAT AN HOUR AND HALF INTO THE FLIGHT THE ENGINE STARTED TO RUN ROUGH AND LOST RPM.  ALL INSTRUMENTS WERE IN THE GREEN.  HE HEADED THE AIRCRAFT FOR A SUITABLE AIRPORT BUT THE ENGINE QUIT IN THE PATTERN.  DUE TO WINDS HE WAS UNABLE TO MAKE THE RUNWAY.  EXAMINATION OF THE ENGINE BY FAA INSPECTORS REVEALED THAT THE NUMBER 4 CYLINDER EXHAUST VALVE FAILED.

## Aircraft

- Registration: [N306AT](https://openairdocs.org/deregistered/N306AT-2013-07-16), registration cancelled 2013-07-16, S/N 306 (OpenAirDocs)
- Reported make and model: GLASAIR SH-2-RG
- Registry model: [Sigler Frank/Norma GLASAIR SHA](https://openairdocs.org/model/sigler-frank-norma-glasair-sha) (registry code 05655SJ) (OpenAirDocs)
- Registry engine: [Lycoming I0360 SER A&C](https://openairdocs.org/engine/lycoming-i0360-ser-a-c) (registry code 41511, reciprocating) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: 306
- Engines: LYCOMING IO-360-A1B 200 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Frank R. Sigler
- Registered owner: Frank R. Sigler
- Last inspection: Unknown, January 2, 2000
- Departed: L18, FALLBROOK, CA
- Destination: TVL, LAKE TAHOE, CA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 63; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; flight hours: 1,330 total, 370 in this make and model, 1,330 as pilot in command, 16 in the last 90 days, 4 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 310° at 20 knots
- Visibility: 30 statute miles
- Lowest ceiling: none

## 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 19910618022369A](https://openairdocs.org/incident/19910618022369A), Jun 18, 1991: Amtr GLASAIR, Visalia, CA, Substantial damage. Engine failed en route. Tried for airport but unable to line up with runway. NR4 cylinder exhaust valve failed.

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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