Individually Owned: 150,657
Corporate Owned: 137,281
Sterling Airport
Aircraft Accident/Incident Report
Sterling, Colorado 80751
Thursday, April 24, 2008 17:10 MDT
NTSB Narrative Summary Released at Completion of Accident
During the landing roll-out, the airline transport pilot said a 50-knot gust of wind hit the twin-engine airplane from the right side. The airplane weathervaned into the wind, at which time he applied full left rudder to compensate. The pilot tried to maintain control of the airplane as it skipped off the right side of the runway onto the grass. Subsequently, the left main gear collapsed due to the side load and the airplane came to an immediate stop. Examination of the airplane revealed that the nose gear had collapsed, the left main gear had separated from the airframe; the right main landing gear remained attached to the airframe, but the upper and lower torque links had separated, and the wheel was rotated to the right. Further examination of the upper and lower link assemblies securing bolt, bushing, two AN washers, castellated nut, and cotter pin, revealed it had pulled through the lower torque link boss, which allowed the main wheel, brake, and strut assembly to rotate inside the strut housing. In addition, both propellers were damaged and the left wing sustained substantial damage. The airplane was last inspected on March 13, 2008, at which time, the main gear camber and toe was adjusted. The failure occurred approximately 39.1 hours after this last inspection. On November 23, 1983, Cessna issued Service Kit SK 421-118, which called for the replacement of washers and for inspection of the main gear torque links. The Service Kit specified washer P/N 504518-2 to be installed under the bolt head and nut, with replacement washer P/N S1450-5H12-063 to be incorporated into the next revision to the Service Kit. Cessna issued a Service Information Letter in conjunction with the Service Kit for the purpose of "improved service life and main gear alignment retention." The washers listed in the Service Kit were not installed on the accident airplane. Compliance with the Service Kit and Service Information Letter is not mandatory.
NTSB Probable Cause Narrative
Failure and separation of the upper and lower right main gear torque links links, which resulted in a loss of directional control on landing roll-out.
Event Information
| Type of Event | Accident |
| Event Date | 4/24/2008 |
| Event Day of the Week | Thursday |
| Time of Event | 1710 |
| Event Time Zone | Mountain Daylight Time |
| Event City | Sterling |
| Event State | COLORADO |
| Event Country | -- |
| Zipcode of the event site | 80751 |
| Event Date Year | 2008 |
| Event Date Month | 4 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 403633N |
| Event Location Longitude | 1031532W |
| Event Location Airport | Sterling |
| Event Location Nearest Airport ID | STK |
| Indicates whether the acc/inc occurred off or on an airport | On Airport |
| Distance from airport in statute miles | 0 |
| Degrees magnetic from airport | -- |
| Airport Elevation | 4400 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1653 Mountain Daylight Time |
| Direction of event from weather observation facility (degrees) | 0 |
| Weather Observation Facility ID | STK |
| Elevation of weather observation facility | 4400 |
| Distance of event from weather observation facility (units?) | 0 |
| Time Zone of the weather observation | MDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 10000 |
| Lowest Non-Ceiling Height | 6000 |
| Sky/Lowest/Cloud Conditions | Scattered |
| Sky Condition for Lowest Ceiling | Overcast |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 17 |
| Dew Point at event time (in degress fahrenheit) | 0 |
| Wind Direction (degrees magnetic) | -- |
| Variable Wind Indicator | Variable |
| Wind Speed (knots) | 5 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Gusting |
| Wind Gust (knots) | 14 |
| Altimeter Setting at event time (in. Hg) | 29.71 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | None |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 3 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | -- |
| NTSB Docket Number (internal use) | 24317 |
| NTSB Notification Source | NTSB Com Center |
| NTSB Notification Date | Apr 24 2008 12:00AM |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Sep 26 2008 6:40PM |
| User who most recently changed record | NTSB\lema |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | Denver FAA/FSDO |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N513FS |
| NTSB Number | DFW08LA115 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 135: Air Taxi & Commuter |
| Type of Flight Plan filed | Company VFR |
| Flight plan Was Activated? | Yes |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Cessna |
| Aircraft Model | 421C |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 421-0510 |
| Certified Max Gross Weight | 7579 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | -- |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 8 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | 100 Hour |
| Date of Last Inspection | Mar 1 2008 12:00AM |
| Airframe hours since last inspection | 79.5 |
| Airframe Hours | 6000 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | ALPINE AIR LLC |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | Telluride |
| Aircraft Owner State | CO |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 81435 |
| Operator is an individual? | No |
| Operator Name | -- |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | -- |
| Operator City | -- |
| Operator State | -- |
| Operator Country | -- |
| Operator Zip code | -- |
| Operator Code | -- |
| Owner has at least one certificate | None |
| Other Operator of large aircraft? | -- |
| Certified for Part 133 or 137 Operation | -- |
| 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 | Passenger Only |
| Type of Flying (Per_Bus / Primary) | -- |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | COS |
| Departure City | Colorado Spring |
| Departure State | CO |
| Departure Country | USA |
| Departure Time | 1630 |
| Departure Time Zone | MDT |
| Destination Same as Local Flt | crash at destination city |
| Destination Airport Code | STK |
| Destination City | Sterling |
| Destination State | CO |
| Destination Country | USA |
| Specific Phase of Flight | Landing - roll |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Sep 12 2008 3:54PM |
| User who most recently changed record | GAMW |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | 33 |
| Runway Length | 4708 |
| Runway Width | 75 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |