Individually Owned: 151,845
Corporate Owned: 143,699
Aircraft Accident/Incident Report
Mount Zion, Kentucky 41030
Thursday, April 30, 1992 13:25 EDT
NTSB Narrative Summary Released at Completion of Accident
WHILE FLYING IN A CRUISE CONFIGURATION AT 1500 FEET MEAN SEA LEVEL, AND ABOUT 10 MINUTES INTO THE FLIGHT THE HELICOPTER STARTED TO VIBRATE. THE PILOT ELECTED TO MAKE A FORCED LANDING IN THE MOST SUITABLE AREA AVAILABLE. DURING THE DESCENT THE VIBRATION CONTINUED TO WORSEN. AT ABOUT 5 FEET ABOVE THE SELECTED LANDING SITE THE PILOT HEARD A LOUD BANG, THE HELICOPTER YAWED TO THE RIGHT AND PITCHED NOSE DOWN. THE PILOT LOWERED THE COLLECTIVE AND PUT THE HELICOPTER ON THE GROUND. METALLURGICAL EXAMINATION DETERMINED THAT THE LOSS OF THE ABRASION STRIP FROM THE LEADING EDGE OF TAIL ROTOR BLADE S/N 5086 INDUCED VIBRATIONAL STRESSES THAT WERE HIGH ENOUGH TO INITIATE FATIGUE FAILURE IN THE TAIL ROTOR GEAR BOX MOUNTING STUDS WHICH RESULTED IN THE SEPARATION OF THE GEAR BOX ASSEMBLY FROM THE HELICOPTER.
NTSB Probable Cause Narrative
AN IN-FLIGHT SEPARATION OF THE TAIL ROTOR ASSEMBLY AS THE RESULT OF THE LOSS OF AN ABRASION STRIP FROM THE LEADING EDGE OF ONE OF THE TAIL ROTOR BLADES, WHICH INDUCED VIBRATIONAL STRESSES HIGH ENOUGH TO INITIATE FATIGUE FAILURE IN THE TAIL ROTOR GEAR BOX MOUNTING STUDS.
Event Information
| Type of Event | Accident |
| Event Date | 4/30/1992 |
| Event Day of the Week | Thursday |
| Time of Event | 1325 |
| Event Time Zone | Eastern Daylight Time |
| Event City | MOUNT ZION |
| Event State | KENTUCKY |
| Event Country | -- |
| Zipcode of the event site | 41030 |
| Event Date Year | 1992 |
| Event Date Month | 4 |
| 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 | 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) | 25 |
| Air Temperature at event time (in degrees celsius) | 24 |
| 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 | Unknown |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | 30 |
| 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 | 3 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 563 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Apr 30 1992 12:00AM |
| NTSB Notification Time | 1500 |
| Fiche Number and/or location -used to find docket information | 47961 |
| Date of most recent change to record | Dec 11 2000 2:51PM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N97BR |
| NTSB Number | NYC92GA089 |
| 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 | MCDONNELL DOUGLAS |
| Aircraft Model | 500E |
| Aircraft Series Identifier | 500E |
| Aircraft Serial Number | 145E |
| Certified Max Gross Weight | 3500 |
| 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 | 4 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | 100 Hour |
| Date of Last Inspection | Jan 2 2000 12:00AM |
| Airframe hours since last inspection | 59 |
| Airframe Hours | 1350 |
| ELT Installed | Yes |
| ELT Activated | Yes |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | US CUSTOMS SERVICE |
| Aircraft Owner Street Address | BOX 115 NAS JACKSONVILLE |
| Aircraft Owner City | JACKSONVILLE |
| Aircraft Owner State | FL |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 32212 |
| Operator is an individual? | -- |
| Operator Name | US CUSTOMS SERVICE |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | BOX 115 NAS JACKSONVILLE |
| Operator City | JACKSONVILLE |
| Operator State | FL |
| Operator Country | |
| Operator Zip code | 32212 |
| 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) | Public Use |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | No |
| Departure Airport Code | CVG |
| Departure City | CINCINNATI |
| Departure State | OH |
| Departure Country | |
| Departure Time | 1310 |
| Departure Time Zone | EDT |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | CVG |
| Destination City | |
| Destination State | |
| Destination Country | |
| Specific Phase of Flight | Descent |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 2 2001 10:30AM |
| 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 | -- |