Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Nunavaugaluk Lk, Alaska 99576
Wednesday, September 9, 1992 10:10 AKD
NTSB Narrative Summary Released at Completion of Accident
SHORTLY AFTER TAKEOFF, AT 1,000 FT AGL, THE PILOT EXPERIENCED AIRFRAME VIBRATION AND A GRINDING SOUND. HE ENTERED AUTOROTATION, AND AT 200 FT AGL THE TAIL ROTOR AND PART OF THE T/R GEAR BOX SEPARATED FROM THE HELICOPTER. IT THEN ROTATED APPROXIMATELY 720 DEG AND IMPACTED THE GROUND. ONE OF THE T/R BLADES WAS MISSING THE ABRASION STRIP. AN AIRWORTHINESS DIRECTIVE (AD) & SERVICE BULLETIN (SB) WERE IN EFFECT DIRECTING INSTALLATION OF RIVETS WITHIN 300 HRS TO PREVENT POSSIBLE LOSS OF TAILROTOR CONTROL. DUE TO SEASONAL USE, HELICOPTER HAD LESS THAN 160 HRS SINCE ISSUANCE OF THE AD. TAIL ROTOR BLADE FOUND INTACT WAS 40% DEBONDED, BUT WOULD PASS A 'TAP TEST' IAW MANUFACTURER'S SB. FAILED BLADE ESTIMATED TO BE 90% DEBONDED. DAILY VISUAL INSPECTION REQUIRED BY SB REPORTEDLY DID NOT DETECT DEBONDING IN PROGRESS.
NTSB Probable Cause Narrative
THE SEPARATION OF THE TAIL ROTOR ABRASION STRIP AND THE SUBSEQUENT TOTAL LOSS OF THE TAIL ROTOR. FACTORS CONTRIBUTING TO THE ACCIDENT WERE: INSUFFICIENT MANUFACTURER'S MAINTENANCE DESIGN CHANGES, INADEQUATE AIRCRAFT EQUIPMENT DESIGN BY THE MANUFACTURER AND INSUFFICIENT STANDARDS OF THE FAA CERTIFICATION ORGANIZATION.
Event Information
| Type of Event | Accident |
| Event Date | 9/9/1992 |
| Event Day of the Week | Wednesday |
| Time of Event | 1010 |
| Event Time Zone | -- |
| Event City | NUNAVAUGALUK LK |
| Event State | ALASKA |
| Event Country | -- |
| Zipcode of the event site | 99576 |
| Event Date Year | 1992 |
| Event Date Month | 9 |
| 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 | 0 |
| Degrees magnetic from airport | 0 |
| Airport Elevation | -- |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Pilot |
| Time of the weather observation | 0 |
| 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 | 3500 |
| Sky/Lowest/Cloud Conditions | Scattered |
| Sky Condition for Lowest Ceiling | Unknown |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 0 |
| Air Temperature at event time (in degrees celsius) | 7 |
| Dew Point at event time (in degress fahrenheit) | 1 |
| Wind Direction (degrees magnetic) | 340 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 8 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Unknown |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | 29 |
| Density Altitude (feet) | 1100 |
| Intensity of Precipitation | Unknown |
| METAR weather report | -- |
| Event Highest Injury | Serious |
| On Ground, Fatal Injuries | 0 |
| On Ground, Minor Injuries | 0 |
| On Ground, Serious Injuries | 0 |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | -- |
| Injury Total Serious | 2 |
| Injury Total All | 2 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 609 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Sep 9 1992 12:00AM |
| NTSB Notification Time | 1350 |
| Fiche Number and/or location -used to find docket information | 48007 |
| Date of most recent change to record | Dec 11 2000 3:17PM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N8697F |
| NTSB Number | ANC92FA159 |
| 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 | None |
| Aircraft Manufacturer's Full Name | HUGHES |
| Aircraft Model | 369D |
| Aircraft Series Identifier | 369D |
| Aircraft Serial Number | 1170221D |
| Certified Max Gross Weight | 3000 |
| 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 | 2 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | May 16 1992 12:00AM |
| Airframe hours since last inspection | 152 |
| Airframe Hours | 3527 |
| ELT Installed | Yes |
| ELT Activated | Yes |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | EBERLE, TERRANCE |
| Aircraft Owner Street Address | 3819 EAST LASALLE ST |
| Aircraft Owner City | PHOENIX |
| Aircraft Owner State | AZ |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 85040 |
| Operator is an individual? | -- |
| Operator Name | EBERLE, TERRANCE |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | 3819 E LASALLE ST |
| Operator City | PHOENIX |
| Operator State | AZ |
| Operator Country | |
| Operator Zip code | 85040 |
| 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) | Business |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | |
| Departure City | CRYSTAL CR LODG |
| Departure State | AK |
| Departure Country | |
| Departure Time | 945 |
| Departure Time Zone | ADT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | |
| Destination City | KOKWOK RIVER |
| Destination State | AK |
| Destination Country | |
| Specific Phase of Flight | Cruise |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 2 2001 10:35AM |
| 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 | -- |