Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Annette Bay, Alaska 99901
Thursday, June 17, 1993 18:00 AKD
NTSB Narrative Summary Released at Completion of Accident
THE HELICOPTER HAD BEEN INVOLVED IN A PREVIOUS TAIL ROTOR STRIKE AND THE DRIVESHAFT WAS INSPECTED. THE ADAPTER ON TAIL ROTOR DRIVE SHAFT NUMBER 4 DEBONDED AND ROTATED ON THE SHAFT. METALLURGICAL EXAMINATION SHOWED DEBONDING BUT THE MODE COULD NOT BE DETERMINED DUE TO ROTATIONAL DAMAGE. OTHER SHAFT ADAPTERS SHOWED DEBONDING AND WERE CAUSED BY PLASTIC BLASTING. THE INSPECTION PROCEDURE CALLS FOR INSPECTIONS ON THE SHAFT USING MAGNETIC PARTICLE OR FLUORESCENT PENETRANT METHODS AND DOES NOT CALL FOR PLASTIC MEDIUM BLASTING.
NTSB Probable Cause Narrative
THE FAILURE OF THE TAIL ROTOR DRIVE SHAFT COUPLING AND THE INADEQUATE INSPECTION OF THE TAIL ROTOR DRIVE SYSTEM BY COMPANY MAINTENANCE PERSONNEL AFTER THE FIRST TAIL ROTOR STRIKE.
Event Information
| Type of Event | Accident |
| Event Date | 6/17/1993 |
| Event Day of the Week | Thursday |
| Time of Event | 1800 |
| Event Time Zone | -- |
| Event City | ANNETTE BAY |
| Event State | ALASKA |
| Event Country | -- |
| Zipcode of the event site | 99901 |
| Event Date Year | 1993 |
| Event Date Month | 6 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| 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 | Not pertinent |
| Investigator's weather source | Pilot |
| Time of the weather observation | 1800 |
| Direction of event from weather observation facility (degrees) | 0 |
| Weather Observation Facility ID | |
| Elevation of weather observation facility | 0 |
| Distance of event from weather observation facility (units?) | 0 |
| Time Zone of the weather observation | |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 0 |
| Lowest Non-Ceiling Height | 0 |
| Sky/Lowest/Cloud Conditions | Clear |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 15 |
| Air Temperature at event time (in degrees celsius) | 10 |
| Dew Point at event time (in degress fahrenheit) | -- |
| Wind Direction (degrees magnetic) | 0 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 0 |
| Wind Velocity Indicator | Calm |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | -- |
| 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 | 4 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 2059 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Jun 18 1993 12:00AM |
| NTSB Notification Time | 1415 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Dec 18 2002 11:28AM |
| User who most recently changed record | NTSB\GIUV |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N21424 |
| NTSB Number | ANC93LA095 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | Company VFR |
| Flight plan Was Activated? | -- |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | Unknown |
| Aircraft Manufacturer's Full Name | Bell |
| Aircraft Model | B-3 |
| Aircraft Series Identifier | B-3 |
| Aircraft Serial Number | 3466 |
| Certified Max Gross Weight | 3200 |
| Aircraft Category | Helicopter |
| Aircraft Registration Class | U.S. Registered/U.S. Soil |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 5 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | AAIP |
| Date of Last Inspection | Jun 3 1993 12:00AM |
| Airframe hours since last inspection | 5 |
| Airframe Hours | 9850 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | ROCKY MOUNTAIN HELICOPTERS INC |
| Aircraft Owner Street Address | P.O. BOX 1337 |
| Aircraft Owner City | PROVO |
| Aircraft Owner State | UT |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 84601 |
| Operator is an individual? | -- |
| Operator Name | ROCKY MOUNTAIN HELICOPTERS INC |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | P.O. BOX 1337 |
| Operator City | PROVO |
| Operator State | UT |
| Operator Country | |
| Operator Zip code | 84601 |
| Operator Code | ZRHL |
| Owner has at least one certificate | Yes - certificate holder |
| Other Operator of large aircraft? | Yes |
| Certified for Part 133 or 137 Operation | External Load |
| 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) | Business |
| Second Pilot on Board | No |
| Departure Point Same as Event | Yes |
| Departure Airport Code | |
| Departure City | |
| Departure State | |
| Departure Country | |
| Departure Time | 1745 |
| Departure Time Zone | AST |
| 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 | Landing |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 2 2001 10:34AM |
| User who most recently changed record | dbo |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 0 |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |