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Aviation safety reports, made easier to study

NTSB Reports is an independent research and search tool for public aviation accident and incident records. It brings NTSB aviation reports, structured fields, docket files, extracted figures, photos, videos, and update history into one searchable interface.

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August 14, 1989 · Piper PA-23-250 · N4838P

Lake Tahoe, CA

Overview

Report Status
Probable Cause
Event Type
Accident
Date
August 14, 1989
Injury Outcomes
2 injuries (2 fatalities)
Location
Lake Tahoe, CA
Aircraft
Piper PA-23-250
Tail Number
N4838P
Injuries
Fatal
Aircraft Damage
Destroyed
NTSB Number
LAX89FA277

APPROACHING THE ARPT, THE PLT RECEIVED LDG INSTRUCTIONS. SECONDS LATER, HIS TRANSMISSIONS WERE ABRUPTLY TERMINATED. WITNESSES OBSERVED THE ACFT ABRUPTLY NOSE OVER & DESCEND INTO WATER AT A HIGH RATE OF SPEED. IT FRAGMENTED UPON IMPACT & IMMEDIATELY SANK. THE ACFT HAD RECENTLY UNDERGONE MAINTENANCE INVOLVING THE REMOVAL & INSTALLATION OF ITS WINGS, & INSTALLATION OF AN AUTOPILOT & ELECTRIC TRIM. FOLLOWING THIS WORK, THE ACFT WAS FLIGHT TESTED. DURING THE TEST, THE PLT EXPERIENCED A LOSS OF CONTROL & THE ACFT PITCHED DOWN IN A MANNER SIMILAR TO THAT DESCRIBED BY WITNESSES TO THE ACCIDENT. EXAM OF THE UPPER STABILATOR PULLEY ASSEMBLY REVEALED THAT ITS RESPECTIVE CONTROL CABLE HAD BEEN WORKING AGAINST THE SIDE OF THE PULLEY. THE PULLEY WAS FRACTURED, & THE CABLE HAD BECOME WEDGED IN THE PULLEY, WHICH (IN TURN) HAD BECOME WEDGED AGAINST THE SIDE OF ITS SUPPORT BRACKET. THIS ACTION RESTRICTED STABILATOR MOVEMENT.

NTSB Probable Cause

DISABLEMENT OF THE STABILATOR FLIGHT CONTROL SYSTEM. A CONTRIBUTING FACTOR WAS: INADEQUATE MAINTENANCE.

Full Narrative

APPROACHING THE ARPT, THE PLT RECEIVED LDG INSTRUCTIONS. SECONDS LATER, HIS TRANSMISSIONS WERE ABRUPTLY TERMINATED. WITNESSES OBSERVED THE ACFT ABRUPTLY NOSE OVER & DESCEND INTO WATER AT A HIGH RATE OF SPEED. IT FRAGMENTED UPON IMPACT & IMMEDIATELY SANK. THE ACFT HAD RECENTLY UNDERGONE MAINTENANCE INVOLVING THE REMOVAL & INSTALLATION OF ITS WINGS, & INSTALLATION OF AN AUTOPILOT & ELECTRIC TRIM. FOLLOWING THIS WORK, THE ACFT WAS FLIGHT TESTED. DURING THE TEST, THE PLT EXPERIENCED A LOSS OF CONTROL & THE ACFT PITCHED DOWN IN A MANNER SIMILAR TO THAT DESCRIBED BY WITNESSES TO THE ACCIDENT. EXAM OF THE UPPER STABILATOR PULLEY ASSEMBLY REVEALED THAT ITS RESPECTIVE CONTROL CABLE HAD BEEN WORKING AGAINST THE SIDE OF THE PULLEY. THE PULLEY WAS FRACTURED, & THE CABLE HAD BECOME WEDGED IN THE PULLEY, WHICH (IN TURN) HAD BECOME WEDGED AGAINST THE SIDE OF ITS SUPPORT BRACKET. THIS ACTION RESTRICTED STABILATOR MOVEMENT.

Flight

Event TypeAccident
Event Time11:12 PDT
Nearest AirportLake Tahoe (0nm N)
Runway0
Flight Plan FiledNone
Aircraft FireNo
Aircraft ExplosionNo

Aircraft

AircraftPiper PA-23-250
Tail NumberN4838P
Aircraft CategoryAir
DamageDestroyed
Operating RulePart 91
Engines2
Engine TypeReciprocating
Engine DetailsLycoming · O-540-A1D5 · Reciprocating · 250
Seats5

People & Injuries

Injury Summary2 injuries (2 fatalities)
Fatal2
Serious0
Minor0
Uninjured0
Total2
Crew 1Age 66 · Third Class

Conditions

ConditionsVMC
LightDaylight
Wind350° @ 8 kt
Visibility50 sm
CeilingNone
Temperature / Dew Point39 C
Altimeter30.00 inHg
Observation Time18:10
Weather SourceWIT

Appendix: Source Data