# NTSB LAX90DVG13: Charles T. Brietigam RV-4, N87CT, San Andreas, CA, July 21, 1990

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Final report
- Date: July 21, 1990, 09:05 local (16:05 UTC)
- Place: San Andreas, CA
- Coordinates: 38.200897, -120.620712 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=38.2009&lon=-120.6207&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious
- Status: Completed, report November 23, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 26581
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX90DVG13
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/26581/pdf
- Page: https://openairdocs.org/ntsb/LAX90DVG13

## Probable cause

THE FAILURE OF FOUR PROPELLER RETENTION BOLTS WHICH REQUIRED THE ENGINE TO BE SHUT DOWN. A FACTOR IN THE ACCIDENT WAS THE PILOT'S MISJUDGEMENT OF THE FORCED LANDING APPROACH.

## Sequence of events

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

- Airframe/component/system failure/malfunction, cruise - normal
  - propeller system/accessories,prop blade retention - elongated
  - propeller system/accessories,prop blade retention - sheared
  - propeller system/accessories,prop blade retention - undertorqued (cause)
- Undershoot, maneuvering - turn to landing area (emergency)
  - planned approach - misjudged, pilot in command (contributing factor)
- In flight collision with object, descent - emergency
  - object - wire,transmission

## Analysis

THE PILOT OF A HOMEBUILT EXPERIENCED A SEVERE ENGINE VIBRATION DURING FLIGHT AND SHUT THE ENGINE DOWN PRIOR TO THE APPROACH. GROUND AND AIRBORNE WITNESSES OBSERVED THE AIRCRAFT APPROACH THE FIELD FROM OVERHEAD. HE PROCEEDED TO LINE THE AIRCRAFT WITH THE RUNWAY AND THEN EXECUTED A 360 DEGREE TURN WHEN OVER THE RUNWAY AT AN ESTIMATED 100 TO 150 FEET. RUNWAY IS 3600 FEET LONG. DURING THE TURN THE AIRCRAFT COLLIDED WITH A POWER LINE AND DESCENDED INTO THE GROUND SHORT OF THE RUNWAY. EXAMINATION OF THE ENGINE FOUND FOUR BROKEN PROPELLER BOLTS AND SEVERE BOLT AND BUSHING ELONGATION ON THE PROPELLER EXTENSION AND SPINNER BULKHEAD.

## Aircraft

- Registration: [N87CT](https://openairdocs.org/deregistered/N87CT-1991-07-12), registration cancelled 1991-07-12, S/N CTB1 (OpenAirDocs)
- Reported make and model: CHARLES T. BRIETIGAM RV-4
- Registry model: [Brietigam Charles T RV-4](https://openairdocs.org/model/brietigam-charles-t-rv-4) (registry code 05612CX) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: CTB-1
- Airframe hours: 115
- Engines: LYCOMING O-320-E2A 150 horsepower reciprocating
- Damage: Destroyed
- Fire: On-Ground
- Flight: Personal, Part 91
- Operator: Brietigam, George S.
- Registered owner: Charles T. Brietigam
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Annual, March 20, 1990, 25 hours before
- Departed: Q60, FRESNO, CA
- Destination: 070, JACKSON, CA
- Airport: O03, Calaveras Co., runway 31, 3,600 × 60 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 45; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: front; flight hours: 450 total, 400 as pilot in command, 25 in the last 90 days, 10 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 50 statute miles
- Lowest ceiling: none
- Temperature: 79 °F, dew point 57 °F
- Altimeter: 29.00 inHg
- Observed at: MHR, 40 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 19900721029229A](https://openairdocs.org/incident/19900721029229A), Jul 21, 1990: Amtrvn VANSRV4, San Andreas, CA, Destroyed. Under torqued prop bolts loosened. Severe vibration. Overshot runway on forced landing,struck wires second approach

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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