Individually Owned: 150,657
Corporate Owned: 137,281
Stellar Airpark Airport
Aircraft Accident/Incident Report
Chandler, Arizona 85248
Tuesady, March 15, 2011 14:00 MST
NTSB Narrative Summary Released at Completion of Accident
The flight instructor and a helicopter-rated pilot were conducting the flight for the purpose of transitioning the pilot to the piston-engine experimental helicopter. About 30 minutes into the flight, while flying straight and level, the pilots felt a jolt followed by loud noise and vibration. The flight instructor reduced power and began looking for a place to land. Erratic engine tachometer indications and additional power reduction then prompted the flight instructor to enter an autorotation for a forced landing. The helicopter had some forward velocity at touchdown on the firm, smooth ground. The skids dug in and the helicopter rolled over. Both pilots were uninjured.
The helicopter used a system of pulleys and sprockets to enable the engine to drive the main rotor at the desired rotational speed. The accident helicopter incorporated a design change for the main drive pulley attachment to the engine flywheel. The original design used three 3/8-inch diameter socket-head bolts to attach the pulley to the flywheel and one other drive component; the revised design used four 1/4-inch diameter cross-slot (Phillips) screws to attach the pulley only to the flywheel. Postaccident examination of the components revealed that the four attach screws had failed due to fatigue. Laboratory examination of other screws from the same manufacturing lot indicated that the screws were in compliance with their design specifications. The failed screws had about 20 hours in service. The torque that could be applied to the cross-slot screws was limited by the slippage of the screwdriver in the screw head, which in turn limited the preload on the screws and the induced friction in the pulley-to-flywheel joint. Those conditions contributed to the cyclic loading of the fasteners, which then resulted in their fatigue failure. Subsequent to the accident, the manufacturer reverted to its original flywheel-pulley attach method and replaced the newer design pulley assemblies with the original configuration.
NTSB Probable Cause Narrative
A design modification that changed the fasteners and components used to attach the main rotor drive pulley to the engine, which resulted in fatigue failure of those fasteners and a complete loss of power to the main rotor.
Event Information
| Type of Event | Accident |
| Event Date | 3/15/2011 |
| Event Day of the Week | Tuesday |
| Time of Event | 1400 |
| Event Time Zone | Mountain Standard Time |
| Event City | Chandler |
| Event State | ARIZONA |
| Event Country | -- |
| Zipcode of the event site | 85248 |
| Event Date Year | 2011 |
| Event Date Month | 3 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 331329N |
| Event Location Longitude | 1115753W |
| Event Location Airport | Stellar Airpark |
| Event Location Nearest Airport ID | P19 |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | 6 |
| Degrees magnetic from airport | -- |
| Airport Elevation | 1177 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1350 Mountain Standard Time |
| Direction of event from weather observation facility (degrees) | 45 |
| Weather Observation Facility ID | CHD |
| Elevation of weather observation facility | 1180 |
| Distance of event from weather observation facility (units?) | 7 |
| Time Zone of the weather observation | MST |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 20000 |
| Lowest Non-Ceiling Height | -- |
| Sky/Lowest/Cloud Conditions | -- |
| Sky Condition for Lowest Ceiling | Broken |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 35 |
| Air Temperature at event time (in degrees celsius) | 27 |
| Dew Point at event time (in degress fahrenheit) | -1 |
| Wind Direction (degrees magnetic) | 180 |
| 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) | 29.95 |
| 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) | 30545 |
| NTSB Notification Source | Operator |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Oct 2 2012 5:44PM |
| User who most recently changed record | coos |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N602RW |
| NTSB Number | WPR11LA167 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | No |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | ROTORWAY |
| Aircraft Model | A600 |
| Aircraft Series Identifier | Talon |
| Aircraft Serial Number | 8011 |
| Certified Max Gross Weight | 1500 |
| 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 | 2 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | 100 Hour |
| Date of Last Inspection | Feb 24 2011 12:00AM |
| Airframe hours since last inspection | 20 |
| Airframe Hours | 121 |
| ELT Installed | No |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | Rotorway International |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | Chandler |
| Aircraft Owner State | AZ |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 85226 |
| Operator is an individual? | No |
| Operator Name | Rotorway International |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | -- |
| Operator City | Chandler |
| Operator State | AZ |
| Operator Country | USA |
| Operator Zip code | 85226 |
| 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 | No |
| Departure Airport Code | P19 |
| Departure City | Chandler |
| Departure State | AZ |
| Departure Country | USA |
| Departure Time | 1330 |
| Departure Time Zone | MST |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | P19 |
| Destination City | Chandler |
| Destination State | AZ |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Oct 2 2012 6:15PM |
| User who most recently changed record | coos |
| Since inspection or accident | Last Inspection |
| Event Location Runway Number and Location | N/A |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |