Individually Owned: 151,845
Corporate Owned: 143,699
Usaf Academy Airfield Airport
Aircraft Accident/Incident Report
Colorado Springs, Colorado 80840
Wednesday, December 8, 2010 13:10 MST
NTSB Narrative Summary Released at Completion of Accident
The flight instructor and student pilot were performing their fourth touch-and-go landing of the day when the student pilot bounced the airplane. The instructor determined that the bounce was not severe and allowed the student to remain on the controls for a second touchdown. As the airplane contacted the runway, the instructor observed the airplane’s nose wheel depart the airplane. The airplane skidded down the runway for about 120 feet on its main landing gear and nose wheel strut before coming to a stop. An examination of the nose landing gear determined that multiple fatigue cracks had originated in the forward machined pockets of the left and right sides of the nose wheel fork. The cracks propagated until the fork could no longer sustain the applied operational loads, at which point overload failure occurred. As a result of the investigation, the airplane manufacturer developed a reinforced nose wheel fork, and the operator conducted a one-time inspection of its fleet of airplanes to identify any other nose wheel forks with fatigue cracks. The operator also implemented a method to nondestructively inspect all their airplanes’ nose wheel forks for fatigue cracks on a periodic basis. Additionally, the operator evaluated and implemented ways to decrease low cycle, high intensity stress brought on by nose wheel shimmy during takeoffs and landings and published guidance outlining specific steps to take in the event of hard landings, bounces, nose wheel strikes, and excessive nose wheel shimmy or vibration.
NTSB Probable Cause Narrative
Fatigue failure of the nose wheel fork, which resulted in separation of the nose wheel.
Event Information
| Type of Event | Incident |
| Event Date | 12/8/2010 |
| Event Day of the Week | Wednesday |
| Time of Event | 1310 |
| Event Time Zone | Mountain Standard Time |
| Event City | Colorado Springs |
| Event State | COLORADO |
| Event Country | -- |
| Zipcode of the event site | 80840 |
| Event Date Year | 2010 |
| Event Date Month | 12 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 385811N |
| Event Location Longitude | 1044846W |
| Event Location Airport | USAF Academy Airfield |
| Event Location Nearest Airport ID | AFF |
| 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 | 6572 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Pilot |
| Time of the weather observation | 1300 Mountain Standard Time |
| Direction of event from weather observation facility (degrees) | 90 |
| Weather Observation Facility ID | AFF |
| Elevation of weather observation facility | -- |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | MST |
| Lighting Conditions | Day |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | -- |
| Sky/Lowest/Cloud Conditions | Clear |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 10 |
| Dew Point at event time (in degress fahrenheit) | -12 |
| Wind Direction (degrees magnetic) | 200 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 4 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 30.09 |
| 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 | 2 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 30036 |
| NTSB Notification Source | US Air Force |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Aug 2 2012 6:22PM |
| User who most recently changed record | snyg |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N326AF |
| NTSB Number | CEN11IA114 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | Military VFR |
| Flight plan Was Activated? | Yes |
| Damage | Minor |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | DIAMOND AIRCRAFT IND INC |
| Aircraft Model | DA 40 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 40.986 |
| Certified Max Gross Weight | 2646 |
| 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 | 4 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | AAIP |
| Date of Last Inspection | Nov 19 2010 12:00AM |
| Airframe hours since last inspection | -- |
| Airframe Hours | 560 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | Unknown |
| Aircraft Owner Name | DOSS AVIATION INC |
| Aircraft Owner Street Address | 3320 CAREFREE CIRCLE WEST |
| Aircraft Owner City | COLORADO SPRINGS |
| Aircraft Owner State | CO |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 80917 |
| Operator is an individual? | No |
| Operator Name | DOSS AVIATION INC |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | 3320 CAREFREE CIRCLE WEST |
| Operator City | COLORADO SPRINGS |
| Operator State | CO |
| Operator Country | USA |
| Operator Zip code | 80917 |
| Operator Code | -- |
| Owner has at least one certificate | None |
| Other Operator of large aircraft? | No |
| Certified for Part 133 or 137 Operation | -- |
| 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 | Yes |
| Departure Point Same as Event | Yes |
| Departure Airport Code | AFF |
| Departure City | Colorado Springs |
| Departure State | CO |
| Departure Country | USA |
| Departure Time | 1250 |
| Departure Time Zone | MST |
| Destination Same as Local Flt | crash at destination city |
| Destination Airport Code | AFF |
| Destination City | Colorado Springs |
| Destination State | CO |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jun 20 2012 4:25PM |
| User who most recently changed record | bowl |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | 16L |
| Runway Length | 3500 |
| Runway Width | 75 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |