# NTSB FTW89LA167: Mooney M20E, N9462V, Brenham, TX, September 17, 1989

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: September 17, 1989, 11:54 local (16:54 UTC)
- Place: Brenham, TX
- Coordinates: 30.149183, -96.389686 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=30.1492&lon=-96.3897&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 2 minor
- Status: Completed, report July 29, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 22919
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW89LA167
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/22919/pdf
- Page: https://openairdocs.org/ntsb/FTW89LA167

## Probable cause

IMPROPER MAINTENANCE, IMPROPERLY SECURED OIL LINE TO THE PROPELLER GOVERNOR, FAILURE OF THE PROPELLER GOVERNOR OIL LINE, AND SUBSEQUENT LOSS OF OIL, WHICH RESULTED IN OIL EXHAUSTION.  FACTORS RELATED TO THE ACCIDENT WERE:  FAILURE OF MAINTENANCE PERSONNEL TO FOLLOW THE SERVICE BULLETIN/INSTRUCTION, AND THE TREE AND ROUGH TERRAIN IN THE EMERGENCY LANDING AREA.

## 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, cruise - normal
  - lubricating system,oil line - not secured (cause)
  - maintenance,top overhaul - improper, other maintenance personnel (cause)
  - maintenance,service bulletin/letter - not followed, other maintenance personnel (contributing factor)
  - lubricating system,oil line - failure,total (cause)
  - propeller governor control - leak (cause)
  - fluid,oil - exhaustion (cause)
- Forced landing, descent - emergency
- On ground/water collision with object, landing - roll
  - object - tree(s) (contributing factor)
- On ground/water encounter with terrain/water, landing - roll
  - terrain condition - rough/uneven (contributing factor)

## Analysis

DURING CRUISE AT 6500 FT, OIL APPEARED ON THE WINDSCREEN. FORWARD VISIBILITY WAS SOON RESTRICTED & SEVERE VIBRATIONS PROMPTED THE PLT TO SECURE THE ENG. SUBSEQUENTLY, THE ACFT WAS DMGD WHEN IT HIT A SMALL TREE & ENCTRD UNEVEN TERRAIN DRG A FORCED LNDG. INV REVEALED A 90 DEG ALUMINUM FITTING ON THE PROP GOVERNOR OIL LINE HAD FAILED WHERE IT ENTERED THE ENG CASE. THE OIL LINE WAS STAINLESS STEEL & ITS MOVEMENT WAS DESIGNED TO BE RESTRAINED BY CLAMPS, WHICH WERE NOT IN PLACE. A SVC INSTRN, ISSUED IN 1986, RCMNDD THAT ALUMINUM FITTINGS BE UPGRADED TO STAINLESS STEEL. A SVC BULLETIN DATED 9/8/89 RELATED TO NUMEROUS 'ENGINE FAILURES DUE TO OIL STARVATION RESULTING FROM BROKEN GOVERNOR LINES.' ACCORDING TO THAT BULLETIN, FAILURE TO RE-INSTALL THE GOVERNOR LINE CLAMPS AFTER MAINT HAD BEEN THE CAUSE OF NUMEROUS ENG FAILURES. MAINT PERSONNEL ACCOMPLISHED BOTH A TOP OVERHAUL & AN ANNUAL INSPN, 50 & 12 HRS, RESPECTIVELY, BFR THE ACDNT.

## Aircraft

- Registration: N9462V (not matched to a registry record)
- Reported make and model: MOONEY M20E
- Category: Airplane
- Serial number: 700036
- Airframe hours: 1442
- Engines: LYCOMING IO-360-A1A 200 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Hall, David W.
- Registered owner: David W Hall
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, March 2, 1989, 12 hours before
- Departed: 9XS2, PORTER, TX
- Destination: PEQ, PECOS, TX
- Flight plan: VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 63; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 2,226 total, 1,275 in this make and model, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 9 statute miles
- Lowest ceiling: none
- Temperature: 81 °F

## 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 19890917035369A](https://openairdocs.org/incident/19890917035369A), Sep 17, 1989: Mooney M20E, Brenham, TX, Substantial damage. Oil on windshiled en route. Shut down, landed in a field striking tree. Unsecured prop governor oil line elbow broke

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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