Skip to content

LAX91FA052

1990-12-09 · PERRIS VALLEY, California, United States · Minor · 1 aircraft · Status: Completed

Airport L65

Current FAA registration · N121PM

Make / Model
DEHAVILLAND DHC-6 TWIN OTTER
Year of manufacture
1966 · 24 years old at event
Engine
U/A CANADA PT6 SER 578HP (550 hp)
Seats / Engines
16 seats · 2 engines
ADS-B equipped
Yes — Mode-S A058BA

Source: FAA Aircraft Registry (releasable master file).

Aircraft involved

Probable cause & findings

A LOSS OF POWER ON THE LEFT ENGINE DUE TO A FATIGUE FAILURE OF A COMPRESSOR TURBINE BLADE LEADING TO FURTHER COMPRESSOR BLADE DAMAGE; A WORN POWER TURBINE GOVERNOR THROTTLE CAM ASSEMBLY WHICH LED TO LOSS OF POWER ON THE RIGHT ENGINE; AND INADEQUATE MAINTENANCE AND INSPECTION BY THE OPERATOR.

Factual narrative

AFTER LIFT-OFF, AT ABOUT 100 FT AGL AND 85 KTS, THE LEFT ENG DECELERATED AND THE AIRPLANE BEGAN TO YAW AND ROLL LEFT. THE PIC ABORTED THE TAKEOFF, TURNED LEFT AND LANDED ON A FLAT LEVEL FIELD. THE AIRPLANE STRUCK A FENCE, THEN TREES. EXAMINATION OF THE LEFT ENG REVEALED THE LOSS OF POWER WAS ATTRIBUTED TO A FATIGUE FRACTURE OF A COMPRESSOR TURBINE BLADE, WHICH LED TO SUBSEQUENT BLADE FRACTURES. THE RIGHT ENG WAS EXAMINED AND FOUND TO HAVE ADVANCE WEAR ON THE THROTTLE CAM ASSEMBLY OF THE POWER TURBINE GOVERNOR. IN A TEST CELL, ONLY APRX 28% OF TAKEOFF POWER COULD BE ACHIEVED. THE CAM LOBE WEAR HAD PROGRESSED OVER AN EXTENDED PERIOD OF TIME. THE RIGHT ENGINE PROP GOVERNOR WAS REPLACED 11/18/90, FOLLOWED BY A TEST RUN. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12

Verbatim from NTSB's published report. Source file NTSB_1990_LAX91FA052.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.

Search this event elsewhere

External sources are reported, not agency: signal that something happened, not fact about what happened.

Related research

Matched on aircraft type or causal vocabulary (maintenance). All research papers