Individually Owned: 150,657
Corporate Owned: 137,281
Steamboat Springs/Bob Adams Fi Airport
Aircraft Accident/Incident Report
Steamboat Sprng, Colorado 80487
Thursday, November 30, 2006 8:50 MST
NTSB Narrative Summary Released at Completion of Accident
During takeoff, the pilot applied power to the engine and the takeoff roll was smooth. The pilot noted that the runway centerline was somewhat obscured by snow and the airplane drifted slightly to the right of centerline. Approximately 50 to 60 knots (1/3 of the way down the runway), the airplane "suddenly turned hard to the left and started to skid." The pilot immediately reduced power to idle and did not apply brakes or reverse. Subsequently, the airplane departed the left side of the runway. After repairs were completed from a previous incident, the accident airplane was equipped with a Supplemental Type Certificate (STC) engine mount that eliminated the need for repetitive inspections required by the airframe manufacturer service bulletins. Due to the number of runway excursions, nose gear failures and recurring cracked engine mounts, the original engine mount was redesigned. The redesign process included finite element model analysis and various testing programs. The original mount design had not incorporated these types of design tools. Post-event engineering examination of the original engine mount and STC'd engine mount revealed that there was compliance (flexibility) in the engine mount actuator attach feet structure, sometimes resulting in the cracking of the engine mount at the actuator feet. This compliance issue was sometimes exasperated at various speeds, resulting in a high speed shimmy effect and subsequent uncommanded left or right turn of the nose wheel during takeoff and/or landing. The new engine mount incorporates a one piece design at the actuator attach point, eliminating the two piece feet design. The one piece design provides a less compliant structure, which prevents relative motion between the two feet in the original engine mount design.
NTSB Probable Cause Narrative
The inadequate design of the engine mount which caused an uncommanded left turn, loss of directional control, and impact with snow covered terrain.
Event Information
| Type of Event | Accident |
| Event Date | 11/30/2006 |
| Event Day of the Week | Thursday |
| Time of Event | 850 |
| Event Time Zone | Mountain Standard Time |
| Event City | Steamboat Sprng |
| Event State | COLORADO |
| Event Country | -- |
| Zipcode of the event site | 80487 |
| Event Date Year | 2006 |
| Event Date Month | 11 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 403058N |
| Event Location Longitude | 1065158W |
| Event Location Airport | STEAMBOAT SPRINGS/BOB ADAMS FI |
| Event Location Nearest Airport ID | SBS |
| 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 | 6878 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Pilot |
| Time of the weather observation | |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | -- |
| Elevation of weather observation facility | -- |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | -- |
| 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) | -27 |
| Dew Point at event time (in degress fahrenheit) | -- |
| Wind Direction (degrees magnetic) | -- |
| Variable Wind Indicator | Variable |
| Wind Speed (knots) | -- |
| Wind Velocity Indicator | Light and Variable |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 30.42 |
| 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 | 1 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 21845 |
| NTSB Notification Source | FAA-Northwest Mountain Region |
| NTSB Notification Date | Nov 30 2006 12:00AM |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Jul 25 2007 12:22PM |
| User who most recently changed record | NTSB\lema |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | Denver, Colorado |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N804JH |
| NTSB Number | DEN07LA030 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | IFR |
| Flight plan Was Activated? | Yes |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Piper |
| Aircraft Model | PA-46-500TP |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 4697044 |
| Certified Max Gross Weight | 3451 |
| 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 | 6 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | Aug 1 2006 12:00AM |
| Airframe hours since last inspection | 55 |
| Airframe Hours | 595 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | Twin Landfill Corporation |
| Aircraft Owner Street Address | 36 Gallatin Field |
| Aircraft Owner City | Bozeman |
| Aircraft Owner State | MT |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 59714 |
| 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 | -- |
| Indicates Domestic or International Flight | -- |
| Operator carrying Pax/Cargo/Mail | -- |
| Type of Flying (Per_Bus / Primary) | Personal |
| Second Pilot on Board | No |
| Departure Point Same as Event | Yes |
| Departure Airport Code | SBS |
| Departure City | STEAMBOAT SPRIN |
| Departure State | CO |
| Departure Country | USA |
| Departure Time | 850 |
| Departure Time Zone | MST |
| Destination Same as Local Flt | -- |
| Destination Airport Code | 1V6 |
| Destination City | CANON CITY |
| Destination State | CO |
| Destination Country | USA |
| Specific Phase of Flight | Takeoff - roll/run |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jun 28 2007 3:11PM |
| User who most recently changed record | BOWL |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | 32 |
| Runway Length | 4482 |
| Runway Width | 100 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |