Individually Owned: 150,657
Corporate Owned: 137,281
Renton Municipal Airport
Aircraft Accident/Incident Report
Renton, Washington 98055
Friday, December 28, 2012 10:15 PST
NTSB Narrative Summary Released at Completion of Accident
On December 28, 2012, about 1015 Pacific standard time (PST), a Bell Helicopter, Model 407, N407KS, made a hard landing during a ground handling operation at Renton Municipal Airport (RNT), Renton, Washington. King County Sheriff’s Department was operating the helicopter under public-use. The commercial pilot was not injured; the helicopter sustained substantial damage to the tail rotor system and to the fuselage. The local law enforcement flight was preparing to departed Renton when the accident occurred. Visual meteorological conditions prevailed, and no flight plan had been filed.
The pilot reported that while preparing to depart from the raised platform, as he increased the throttle the platform started to rotate. The pilot attempted to stop the rotation by retarding the throttle, but was unsuccessful. The helicopter came off of the platform and the helicopter sustained damage to the tail rotor system, fuselage, and the landing gear.
The platform was locally fabricated by the King County Sheriff’s Department. It consisted of a platform with 8 sets of casters (total of 16 wheels). The sheriff uses these carts to move aircraft in and out of their hangar. With the exception of the rear fixed casters, the remaining 6 sets of casters swivel. The fixed casters (one wheel in each corner of the cart) were chocked to prevent movement of the cart before the aircraft was operated.
Other operators at RNT use similar landing platforms which use six casters. It was noted that these operators chock the corner swivel casters to prevent movement of the cart.
NTSB Probable Cause Narrative
Not Yet Reported
Event Information
| Type of Event | Accident |
| Event Date | 12/28/2012 |
| Event Day of the Week | Friday |
| Time of Event | 1015 |
| Event Time Zone | Pacific Standard Time |
| Event City | Renton |
| Event State | WASHINGTON |
| Event Country | -- |
| Zipcode of the event site | 98055 |
| Event Date Year | 2012 |
| Event Date Month | 12 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 472921N |
| Event Location Longitude | 1221234W |
| Event Location Airport | Renton Municipal Airport |
| Event Location Nearest Airport ID | RNT |
| 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 | 32 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Unknown |
| Time of the weather observation | 953 Pacific Standard Time |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | RNT |
| Elevation of weather observation facility | 32 |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | PST |
| 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) | 40 |
| Dew Point at event time (in degress fahrenheit) | 38 |
| 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) | 30.14 |
| 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) | -- |
| NTSB Notification Source | FAA NWM Operations Center |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Jan 10 2013 12:58PM |
| User who most recently changed record | coos |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N407KS |
| NTSB Number | WPR13TA081 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Public Use |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | No |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | -- |
| Aircraft Manufacturer's Full Name | BELL HELICOPTER TEXTRON CANADA |
| Aircraft Model | 407 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 53812 |
| Certified Max Gross Weight | -- |
| Aircraft Category | Helicopter |
| 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 | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | -- |
| Date of Last Inspection | -- |
| Airframe hours since last inspection | -- |
| Airframe Hours | -- |
| ELT Installed | Unknown |
| ELT Activated | Unknown |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | KING COUNTY SHERIFFS OFFICE |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | SEATTLE |
| Aircraft Owner State | WA |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 98104-2392 |
| Operator is an individual? | No |
| Operator Name | KING COUNTY SHERIFFS OFFICE |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | -- |
| Operator City | SEATTLE |
| Operator State | WA |
| Operator Country | USA |
| Operator Zip code | 98104-2392 |
| 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) | -- |
| Second Pilot on Board | No |
| Departure Point Same as Event | Yes |
| Departure Airport Code | RNT |
| Departure City | Renton |
| Departure State | WA |
| Departure Country | USA |
| Departure Time | -- |
| Departure Time Zone | PST |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | RNT |
| Destination City | Renton |
| Destination State | WA |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 10 2013 12:58PM |
| User who most recently changed record | coos |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | N/A |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |