Jefferson County Airport
Aircraft Accident/Incident Report

Broomfield, Colorado 80020
Thursday, December 5, 1991 16:45 MST

NTSB Narrative Summary Released at Completion of Accident

UPON RETURN FROM A LOCAL AREA INSTRUCTIONAL FLIGHT, THE LEFT MAIN LANDING GEAR FAILED TO EXTEND. AFTER REPEATED UNSUCCESSFUL ATTEMPTS TO EXTEND AND LOCK THE LEFT MAIN LANDING GEAR, THE PILOT MADE AN INTENTIONAL WHEELS UP LANDING. POST INCIDENT EXAMINATION DISCLOSED THE LANDING GEAR PIVOT ASSEMBLY FAILED IN DUCTILE TORSIONAL OVERSTRESS. THERE WAS NO EVIDENCE OF FATIGUE OR PREEXISTING CRACKS.

NTSB Probable Cause Narrative

FAILURE OF THE LEFT MAIN LANDING GEAR PIVOT ASSEMBLY DUE TO DUCTILE TORSIONAL OVERSTRESS.

Event Information

Type of Event Incident
Event Date 12/5/1991
Event Day of the Week Thursday
Time of Event 1645
Event Time Zone Mountain Standard Time
Event City BROOMFIELD
Event State COLORADO
Event Country --
Zipcode of the event site 80020
Event Date Year 1991
Event Date Month 12
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport JEFFERSON COUNTY
Event Location Nearest Airport ID BJC
Indicates whether the acc/inc occurred off or on an airport On Airport
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation 5657
Weather Briefing Completeness Unknown
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 Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 20000
Sky/Lowest/Cloud Conditions Thin Broken
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 20
Air Temperature at event time (in degrees celsius) 5
Dew Point at event time (in degress fahrenheit) -4
Wind Direction (degrees magnetic) 300
Variable Wind Indicator Unknown
Wind Speed (knots) 8
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
Density Altitude (feet) 5701
Intensity of Precipitation Unknown
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) 5036
NTSB Notification Source --
NTSB Notification Date --
NTSB Notification Time 0
Fiche Number and/or location -used to find docket information 45883
Date of most recent change to record Dec 12 2000 10:53AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N9320D
NTSB Number DEN92IA014
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Minor
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name CESSNA
Aircraft Model 172RG
Aircraft Series Identifier 172RG
Aircraft Serial Number 172RG1119
Certified Max Gross Weight 2650
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 4
Number of Engines 1
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Oct 4 1991 12:00AM
Airframe hours since last inspection 76
Airframe Hours 4458
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name KEIGTH A. FRANZ
Aircraft Owner Street Address 9867 SO. FALCON CREEK DR.
Aircraft Owner City HIGHLANDS RANCH
Aircraft Owner State CO
Aircraft Owner Country
Aircraft Owner Zipcode 80126
Operator is an individual? --
Operator Name AIRWEST FLYING CLUB
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address 11855 AIRPORT WAY HANGAR B4
Operator City BROOMFIELD
Operator State CO
Operator Country
Operator Zip code 80021
Operator Code CJJS
Owner has at least one certificate None
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 --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) Instructional
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code
Departure City
Departure State
Departure Country
Departure Time 1500
Departure Time Zone MST
Destination Same as Local Flt dest & departure same, accident can occur anywhere
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 29
Runway Length 9000
Runway Width 100
Sight Seeing flight No
Air Medical Flight No
Medical Flight --