# NTSB FTW91LA140: Beech K35, N8111R, Laredo, TX, August 3, 1991

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: August 3, 1991, 10:10 local (15:10 UTC)
- Place: Laredo, TX
- Coordinates: 27.549638, -99.459037 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=27.5496&lon=-99.4590&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor, 3 uninjured
- Status: Completed, report March 24, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 23383
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW91LA140
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/23383/pdf
- Page: https://openairdocs.org/ntsb/FTW91LA140

## Probable cause

THE IMPROPER INSTALLATION OF THE OIL FILTER ADAPTOR 'O' RING (SEAL) BY OTHER MAINTENANCE PERSONNEL WHO DISTORTED IT. A FACTOR WAS THE ROUGH, UNEVEN 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, cruise
  - lubricating system,oil seal - distorted (cause)
  - maintenance,installation - improper, other maintenance personnel (cause)
  - emergency procedure - performed, pilot in command
- Forced landing, descent - emergency
- Nose over, landing - roll
  - terrain condition - rough/uneven (contributing factor)

## Analysis

WHILE IN CRUISE FLIGHT, THE PILOT NOTED AN UNSUAL SMELL WHICH HE THOUGHT MIGHT HAVE BEEN ELECTRICAL OR SMOKE. SHORTLY THEREAFTER, THE AIRPLANE'S ENGINE OIL PRESSURE DECREASED. THE POWERPLANT THEN STARTED TO VIBRATE AND THE PILOT SHUT IT OFF. THE PILOT WAS COMMUNICATING WITH AIR TRAFFIC CONTROL AND WAS ATTEMPTING A PRECAUTIONARY LANDING AT AN AIRPORT WHEN THE FORCED LANDING OCCURRED. THE AIRPLANE WAS LANDED IN AN OPEN FIELD APPROXIMATELY ONE MILE FROM THE END OF THE RUNWAY THAT THE PILOT HAD BEEN CLEARED TO LAND ON. THE AIRPLANE FLIPPED OVER DURING THE LANDING ROLL ON THE UNSUITABLE TERRAIN. POST ACCIDENT EXAMINATION REVEALED THAT AN 'O' RING IN THE OIL FILTER ADAPTOR ASSEMBLY WAS CRUSHED AND THE ENGINE OIL ESCAPED AT THAT DAMAGED AREA CAUSING THE LOSS OF POWER. NO OIL REMAINED IN THE ENGINE. THE ADAPTOR ASSEMBLY HAD BEEN WORKED ON THE DAY BEFORE THE FLIGHT BY OTHER MAINTENANCE PERSONNEL.

## Aircraft

- Registration: [N8111R](https://openairdocs.org/deregistered/N8111R-2012-09-10), registration cancelled 2012-09-10, S/N D-5940, built 1959 (OpenAirDocs)
- Reported make and model: BEECH K35
- Registry model: [Beech K35](https://openairdocs.org/model/beech-k35) (registry code 1151524) (OpenAirDocs)
- Registry engine: [Continental I0-470 series](https://openairdocs.org/engine/continental-i0-470-series) (registry code 17027, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: D5940
- Airframe hours: 3114
- Engines: CONTINENTAL IO-470-C 250 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Dan R. Blaker
- Registered owner: Dan R. Blaker
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, March 8, 1991, 28 hours before
- Departed: HRL, HARLINGEN, TX
- Destination: 6R6, DRYDEN, TX
- Flight plan: VFR
- Airport: LRD, Laredo International, runway 14, 5,926 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 43; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 698 total, 181 in this make and model, 619 as pilot in command, 26 in the last 90 days, 7 in the last 30 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 140° at 10 knots
- Visibility: 12 statute miles
- Lowest ceiling: none
- Temperature: 84 °F, dew point 70 °F
- Altimeter: 30.00 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 19910803031339A](https://openairdocs.org/incident/19910803031339A), Aug 3, 1991: Beech K35, Laredo, TX, Substantial damage. Lost oil pressure. Engine seized. Landed short near airport. O ring oil filter adapter crushed. Just installed.

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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