# NTSB LAX85LA391: Mooney M20K, N5788U, Rosamond, CA, September 15, 1985

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: September 15, 1985, 14:05 local (21:05 UTC)
- Place: Rosamond, CA
- Coordinates: 34.870601, -118.339889 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=34.8706&lon=-118.3399&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 24835
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX85LA391
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/24835/pdf
- Page: https://openairdocs.org/ntsb/LAX85LA391

## 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 pressure pump - jammed (cause)
  - maintenance,inspection - inadequate, other maintenance personnel (cause)
  - lubricating system,oil pressure pump - foreign object (cause)
  - engine assembly,connecting rod - separation (contributing factor)
- Forced landing, descent - emergency

## Analysis

WHILE ENROUTE TO VAN NUYS ARPT AT ABOUT 9500 FT, THE PLT REPORTED TO EDWARDS AFB APCH CONTROL THAT HE WAS EXPERIENCING A ROUGH RUNNING ENG. THE PLT REQUESTED AND RECEIVED A RADAR VECTOR TO WM J. FOX ARPT, LANCASTER, CA. SHORTLY THEREAFTER THE ENG SUSTAINED A TOTAL PWR LOSS. THE PLT EXECUTED AN EMERGENCY NEAR ROSAMOND ARPT. THE ENG EXAMINATION DISCLOSED A 'DRILL BIT' REMNANT LODGED IN HE OIL PUMP CAUSING IT TO SIEZE. THE ENG SUSTAINED EXTREME HIGH TEMP DISTRESS FOLLOWED BY SEPARATION OF THE CON ROD. A 100-HOUR INSPECTION WAS PERFORMED ON THE ACFT WITHIN 80 HOURS PRECEDING THE ACCIDENT. THE MECHANIC REPORTED THAT HE COULD NOT REMEMBER IF HE HAD INSPECTED THE SCAVENGE PUMP OIL SCREEN DURING THE INSPECTION. METALURGICAL EXAMINATION DISCLOSED THE DRILL BIT HAD PENETRATED THE OIL SCREEN AND ENTERED INTO THE OIL PUMP. THE ORIGIN OF THE DRILL BIT COULD NOT BE DETERMINED. THE ENG HAD BEEN DISASSEMBLED 180 HOURS PRIOR TO THE ACCIDENT BY TELEDYNE CONTINENTAL MOTORS

## Aircraft

- Registration: [N5788U](https://openairdocs.org/deregistered/N5788U-2013-06-07), registration cancelled 2013-06-07, S/N 25-0852, built 1984 (OpenAirDocs)
- Reported make and model: MOONEY M20K
- Registry model: [Mooney M20K](https://openairdocs.org/model/mooney-m20k) (registry code 5870220) (OpenAirDocs)
- Category: Airplane
- Serial number: 25-0852
- Airframe hours: 180
- Engines: CONTINENTAL TSIO-360-LB 180 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Nicholas Mendoza
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, July 25, 1985, 80 hours before
- Departed: MMH, MAMMOTH, CA
- Destination: VNY, VAN NUYS, CA
- Flight plan: VFR
- Airport: LOO, Rosamond

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 44; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 430 total, 87 in this make and model, 379 as pilot in command, 60 in the last 90 days, 20 in the last 30 days, 6 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 270° at 25 knots
- Visibility: 30 statute miles
- Lowest ceiling: none
- Temperature: 54 °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 19850915045059A](https://openairdocs.org/incident/19850915045059A), Sep 15, 1985: Mooney M20K, Rosamond, CA, Substantial damage. Engine seized, impacted short of runway. A piece of drilling bit punctured oil screen. Lodged in stopped oil pump.

## Other investigations on N5788U (1)

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.

- [NTSB LAX94FA278](https://openairdocs.org/ntsb/LAX94FA278), Nov 30, 1993: Mooney M20K (N5788U), June Lake, CA, destroyed, 2 fatal. Probable cause: THE PILOT ALLOWED THE AIRPLANE TO EXCEED ITS DESIGN LIMITS (AIRSPEED AND/OR STRESS LIMITS) AFTER INADVERTENTLY ENTERING A DESCENT. FACTORS RELATING TO THE ACCIDENT WERE: DARKNESS (NIGHT OR LATE…

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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