Individually Owned: 151,845
Corporate Owned: 143,699
Aircraft Accident/Incident Report
Gregory, Michigan 48137
Monday, October 7, 2002 18:30 EDT
NTSB Narrative Summary Released at Completion of Accident
While in cruise flight, the secondary drive shaft failed completely and power to the main rotor was lost. The pilot executed an autorotation to an open field. However, on landing, the forward speed was higher than planned and the helicopter flipped forward and rolled to the left. The pilot stated that on his return to the airport, the secondary shaft bearing temperature started to rise. Once the bearing temperature reached 150 degrees Fahrenheit, the "drive let go", causing the engine RPM to surge. A post-accident inspection revealed that the secondary shaft had failed at a point inside the upper bearing race. Due to a history of failures of this secondary shaft design, Rotorway had released a 35 mm diameter shaft configuration in April 2001. The preceeding shaft diameter was 30 mm. An advisory bulletin was issued by Rotorway in May 2002. The 30 mm configuration was installed on the accident aircraft. In addition, the accident aircraft incorporated an after-market cog belt drive system between the secondary shaft and the main rotor shaft. The basic Rotorway design utilizes a chain drive system.
NTSB Probable Cause Narrative
Failure of the secondary drive shaft, which resulted in a complete loss of power to the main rotor, and a high forward airspeed on touchdown, causing the helicopter to flip forward.
Event Information
| Type of Event | Accident |
| Event Date | 10/7/2002 |
| Event Day of the Week | Monday |
| Time of Event | 1830 |
| Event Time Zone | Eastern Daylight Time |
| Event City | Gregory |
| Event State | MICHIGAN |
| Event Country | -- |
| Zipcode of the event site | 48137 |
| Event Date Year | 2002 |
| Event Date Month | 10 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 422700N |
| Event Location Longitude | 0840300W |
| Event Location Airport | -- |
| Event Location Nearest Airport ID | -- |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | -- |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1840 Eastern Daylight Time |
| Direction of event from weather observation facility (degrees) | 20 |
| Weather Observation Facility ID | OZW |
| Elevation of weather observation facility | 960 |
| Distance of event from weather observation facility (units?) | 12 |
| Time Zone of the weather observation | EDT |
| 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) | 11 |
| Dew Point at event time (in degress fahrenheit) | -3 |
| Wind Direction (degrees magnetic) | 310 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 3 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 30.19 |
| 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) | 13568 |
| NTSB Notification Source | FAA |
| NTSB Notification Date | Oct 7 2002 12:00AM |
| NTSB Notification Time | 1950 |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Jul 1 2003 9:44AM |
| User who most recently changed record | NTSB\MONR |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | Detroit FSDO |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N1955Z |
| NTSB Number | CHI03LA006 |
| 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 | Wolf |
| Aircraft Model | Rotorway Exec-162F |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 6365 |
| Certified Max Gross Weight | 1500 |
| Aircraft Category | Helicopter |
| Aircraft Registration Class | U.S. Registered/U.S. Soil |
| Aircraft is a homebuilt? | Yes |
| 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 | Conditional |
| Date of Last Inspection | Aug 28 2002 12:00AM |
| Airframe hours since last inspection | 25 |
| Airframe Hours | 155 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | J. Mark Wolf |
| Aircraft Owner Street Address | 2855 Masters Court |
| Aircraft Owner City | Pinkney |
| Aircraft Owner State | IL |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 48169 |
| Operator is an individual? | Yes |
| 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) | Instructional |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | OZW |
| Departure City | Howell |
| Departure State | MI |
| Departure Country | USA |
| Departure Time | 1800 |
| Departure Time Zone | EDT |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | -- |
| Destination City | -- |
| Destination State | -- |
| Destination Country | -- |
| Specific Phase of Flight | Cruise |
| Report sent to ICAO? | No |
| Evacuation occurred | No |
| Date of most recent change to record | May 1 2003 9:37AM |
| User who most recently changed record | SULP |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | N/A |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |