Stapleton International Airport
Aircraft Accident/Incident Report

Denver, Colorado 80217
Friday, November 29, 1991 3:05 MST

NTSB Narrative Summary Released at Completion of Accident

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 Narrative

A FALSE UNSAFE LANDING GEAR INDICATION DUE TO A FROZEN DOWN LOCK SWITCH. FACTORS WERE: ICING CONDITIONS AND LOW CEILINGS.

Event Information

Type of Event Accident
Event Date 11/29/1991
Event Day of the Week Friday
Time of Event 305
Event Time Zone Mountain Standard Time
Event City DENVER
Event State COLORADO
Event Country --
Zipcode of the event site 80217
Event Date Year 1991
Event Date Month 11
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport STAPLETON INTERNATIONAL
Event Location Nearest Airport ID DEN
Indicates whether the acc/inc occurred off or on an airport On Airport
Distance from airport in statute miles 0
Degrees magnetic from airport 0
Airport Elevation 5333
Weather Briefing Completeness Full
Investigator's weather source Witness
Time of the weather observation 0
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID
Elevation of weather observation facility 0
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation
Lighting Conditions Night/Dark
Lowest Ceiling Height 400
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Unknown
Sky Condition for Lowest Ceiling Overcast
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 1
Air Temperature at event time (in degrees celsius) -2
Dew Point at event time (in degress fahrenheit) -2
Wind Direction (degrees magnetic) 360
Variable Wind Indicator Unknown
Wind Speed (knots) 0
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 29
Density Altitude (feet) 0
Intensity of Precipitation Moderate
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor --
Injury Total None 2
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 1523
NTSB Notification Source --
NTSB Notification Date --
NTSB Notification Time 0
Fiche Number and/or location -used to find docket information 45374
Date of most recent change to record Dec 12 2000 10:51AM
User who most recently changed record dbo
Basic weather conditions Instrument Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N354AC
NTSB Number DEN92LA012
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 135: Air Taxi & Commuter
Type of Flight Plan filed IFR
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name PIPER
Aircraft Model PA-31-350
Aircraft Series Identifier PA-31-350
Aircraft Serial Number 31-7752049
Certified Max Gross Weight 7000
Aircraft Category Airplane
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 2
Number of Engines 2
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Unknown
Date of Last Inspection --
Airframe hours since last inspection 0
Airframe Hours --
ELT Installed Yes
ELT Activated Yes
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name
Aircraft Owner Street Address
Aircraft Owner City
Aircraft Owner State
Aircraft Owner Country
Aircraft Owner Zipcode
Operator is an individual? --
Operator Name ALPINE AIR, INC.
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address P.O. BOX 691
Operator City PROVO
Operator State UT
Operator Country
Operator Zip code 84603
Operator Code TIMA
Owner has at least one certificate Yes - certificate holder
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation Unknown
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not Non-scheduled
Indicates Domestic or International Flight Domestic
Operator carrying Pax/Cargo/Mail Cargo
Type of Flying (Per_Bus / Primary) Unknown
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code SLC
Departure City SALT LAKE CITY
Departure State UT
Departure Country
Departure Time 30
Departure Time Zone MST
Destination Same as Local Flt crash at destination city
Destination Airport Code
Destination City
Destination State
Destination Country
Specific Phase of Flight Landing
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:35AM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 26
Runway Length 10004
Runway Width 150
Sight Seeing flight No
Air Medical Flight No
Medical Flight --