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NTSB Report
November 29, 1991 · Piper PA-31-350 · N354AC
Denver, CO
Overview
Report Status
Probable Cause
Event Type
Accident
Date
November 29, 1991
Injury Outcomes
No injuries (2 uninjured)
Location
Denver, CO
Aircraft
Piper PA-31-350
Tail Number
N354AC
Operator
Alpine Air
Injuries
None
Aircraft Damage
Substantial
NTSB Number
DEN92LA012
DURING THE APPROACH, THE PILOT COULD NOT OBTAIN A GEAR DOWN AND LOCKED INDICATION ON THE LEFT MAIN LANDING GEAR. HE ELECTED TO LAND GEAR UP WHICH CAUSED SUBSTANTIAL DAMAGE TO THE BOTTOM OF THE FUSELAGE. POSTACCIDENT TESTS REVEALED THAT THE LEFT MAIN LANDING GEAR DOWN LOCK SWITCH HAD FROZEN FROM AN ACCUMULATION OF ICE. WEATHER CONDITIONS AT THE TIME INCLUDED ICING, LOW CEILINGS AND LOW VISIBILITY. PRIOR TO THE ACCIDENT, THE PILOT REPORTED ACCUMULATIONS OF MODERATE ICE. FOLLOWING THE ACCIDENT, ICE ACCUMULATION OF UP TO 3 INCHES WAS FOUND ON THE AIRCRAFT.
NTSB Probable Cause
A FALSE UNSAFE LANDING GEAR INDICATION DUE TO A FROZEN DOWN LOCK SWITCH. FACTORS WERE: ICING CONDITIONS AND LOW CEILINGS.
Full Narrative
DURING THE APPROACH, THE PILOT COULD NOT OBTAIN A GEAR DOWN AND LOCKED INDICATION ON THE LEFT MAIN LANDING GEAR. HE ELECTED TO LAND GEAR UP WHICH CAUSED SUBSTANTIAL DAMAGE TO THE BOTTOM OF THE FUSELAGE. POSTACCIDENT TESTS REVEALED THAT THE LEFT MAIN LANDING GEAR DOWN LOCK SWITCH HAD FROZEN FROM AN ACCUMULATION OF ICE. WEATHER CONDITIONS AT THE TIME INCLUDED ICING, LOW CEILINGS AND LOW VISIBILITY. PRIOR TO THE ACCIDENT, THE PILOT REPORTED ACCUMULATIONS OF MODERATE ICE. FOLLOWING THE ACCIDENT, ICE ACCUMULATION OF UP TO 3 INCHES WAS FOUND ON THE AIRCRAFT.
Flight
Event TypeAccident
Event Time03:05 MST
Nearest AirportStapleton International (0nm N)
Runway26
Runway Length10004 ft
Runway Width150 ft
Flight Plan FiledIFR
Aircraft FireNo
Aircraft ExplosionNo
Aircraft
AircraftPiper PA-31-350
Tail NumberN354AC
Aircraft CategoryAir
DamageSubstantial
OperatorAlpine Air
Operating RulePart 135
Engines2
Engine TypeReciprocating
Engine DetailsLycoming · LTSID-540-J2B · Reciprocating · 350
Seats2
People & Injuries
Injury SummaryNo injuries (2 uninjured)
Fatal0
Serious0
Minor0
Uninjured2
Total2
Crew 1Age 30 · First Class
Conditions
ConditionsIMC
LightDark Night
Wind360°
Visibility1 sm
CeilingOvercast 400 ft
Temperature / Dew Point28 C / 28 C
Altimeter29.00 inHg
Weather SourceWIT