Individually Owned: 150,657
Corporate Owned: 137,281
Memorial Airport
Aircraft Accident/Incident Report
Chandler, Arizona 85226
Thursday, April 6, 2000 8:00 MST
NTSB Narrative Summary Released at Completion of Accident
The helicopter landed hard collapsing the left skid and resulting in the main rotor blades striking the tail boom. While in the traffic pattern, during the downwind leg, the pilot heard a loud noise from the rear of the helicopter. He entered an autorotation and checked the cockpit instruments. Noting no anomalies, he rolled on the throttle and discovered that the engine speed would increase but the rotor speed would not. The pilot flared to avoid a fence then landed hard. Subsequent examination of the engine secondary shaft that transmits power to the main rotor through drive belts revealed that the shaft had failed in fatigue. There were numerous longitudinal and circumferential score marks on the secondary shaft indicating removal and reinstallation of the shaft many times. The fatigue fracture originated at one of the circumferential score marks and exhibited oxidation, indicating it had been fractured for some time.
NTSB Probable Cause Narrative
The inadequate maintenance inspection of the secondary shaft which resulted in its fatigue failure that emanated from a corroded circumferential score mark. A factor was the fence that the pilot flared to avoid, resulting in a hard landing.
Event Information
| Type of Event | Accident |
| Event Date | 4/6/2000 |
| Event Day of the Week | Thursday |
| Time of Event | 800 |
| Event Time Zone | Mountain Standard Time |
| Event City | CHANDLER |
| Event State | ARIZONA |
| Event Country | -- |
| Zipcode of the event site | 85226 |
| Event Date Year | 2000 |
| Event Date Month | 4 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | -- |
| Event Location Longitude | -- |
| Event Location Airport | MEMORIAL |
| Event Location Nearest Airport ID | |
| 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 | 1185 |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 756 Mountain Standard Time |
| Direction of event from weather observation facility (degrees) | 300 |
| Weather Observation Facility ID | PHX |
| Elevation of weather observation facility | 1135 |
| Distance of event from weather observation facility (units?) | 13 |
| Time Zone of the weather observation | MST |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 0 |
| Lowest Non-Ceiling Height | 25000 |
| Sky/Lowest/Cloud Conditions | Scattered |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 68 |
| Dew Point at event time (in degress fahrenheit) | 36 |
| Wind Direction (degrees magnetic) | 80 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 6 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | 29 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | Unknown |
| METAR weather report | -- |
| Event Highest Injury | None |
| On Ground, Fatal Injuries | 0 |
| On Ground, Minor Injuries | 0 |
| On Ground, Serious Injuries | 0 |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 2 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 10883 |
| NTSB Notification Source | FAA |
| NTSB Notification Date | Apr 27 2000 12:00AM |
| NTSB Notification Time | 1400 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Nov 1 2001 7:36AM |
| User who most recently changed record | NTSB\MONR |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N21901 |
| NTSB Number | LAX00LA173 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | -- |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Rotorway |
| Aircraft Model | EXEC 162F |
| Aircraft Series Identifier | EXEC 162F |
| Aircraft Serial Number | RI6035 |
| 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 | 100 Hour |
| Date of Last Inspection | Apr 3 2000 12:00AM |
| Airframe hours since last inspection | 8 |
| Airframe Hours | 1200 |
| ELT Installed | Unknown |
| ELT Activated | Unknown |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | COBB INTERNATIONAL |
| Aircraft Owner Street Address | 4140 W. MERCURY WAY |
| Aircraft Owner City | CHANDLER |
| Aircraft Owner State | AZ |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 85226 |
| Operator is an individual? | -- |
| 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? | No |
| Certified for Part 133 or 137 Operation | Unknown |
| 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 | P19 |
| Departure City | |
| Departure State | AZ |
| Departure Country | |
| Departure Time | 0 |
| Departure Time Zone | |
| 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 | Approach |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Oct 17 2001 10:40AM |
| User who most recently changed record | dbo |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 12 |
| Runway Length | 8500 |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |