Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Couer D'alene, Idaho 83814
Thursday, June 18, 1998 8:20 PDT
NTSB Narrative Summary Released at Completion of Accident
The pilot stated that he heard a loud metallic bang coming from the rear of the aircraft, followed immediately by a loss of power. He elected not to auto-rotate to a landing at the log-landing because of personnel in the vicinity, so he initiated an approach to a logging road adjacent to the log-landing. He landed with skids level, no power, and very low rotor rpm, but felt that he had the road made. After touching down, the helicopter rocked backward and rolled over on its left side. The engine was still running, and the pilot shut it down with the fuel valve. During the course of engine disassembly and inspection, output reduction gearbox damage was found to be consistent with a number one planet gearshaft separation caused by fatigue initiating at the outside diameter of the gear shaft within the shaft/gear web shoulder fillet radius. Laboratory analysis of the remnants of the number one planet gear noted that a cross section through the apparent fatigue origin did not exhibit evidence of material defects; however the fatigue initiation area was obscured as a result of secondary damage. The outer diameter of the planet gear shaft was found to have been plated with chromium or nickel and the case hardness of the carburized case on the planet gear was below that specified by the manufacturer. Investigation determined that none of the three planet gears in this engine were of OEM manufacture. Plating of the planet gear is not an authorized repair procedure, and no military repair procedure was identified authorizing this type of repair.
NTSB Probable Cause Narrative
Fatigue failure of a reduction drive planetary gear. Factors include an unapproved part and plating process, and uneven terrain at the emergency landing site.
Event Information
| Type of Event | Accident |
| Event Date | 6/18/1998 |
| Event Day of the Week | Thursday |
| Time of Event | 820 |
| Event Time Zone | Pacific Daylight Time |
| Event City | COUER D'ALENE |
| Event State | IDAHO |
| Event Country | -- |
| Zipcode of the event site | 83814 |
| Event Date Year | 1998 |
| 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 | 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) | 100 |
| Air Temperature at event time (in degrees celsius) | 21 |
| Dew Point at event time (in degress fahrenheit) | -- |
| Wind Direction (degrees magnetic) | 270 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 5 |
| 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 | 1 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 1485 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Jun 18 1998 12:00AM |
| NTSB Notification Time | 1000 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Dec 11 2000 11:33AM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N869W |
| NTSB Number | SEA98FA104 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 133: Rotorcraft Ext. Load |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | -- |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Garlick |
| Aircraft Model | UH-1H |
| Aircraft Series Identifier | UH-1H |
| Aircraft Serial Number | 68-15530 |
| Certified Max Gross Weight | 9500 |
| 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 | AAIP |
| Date of Last Inspection | Jun 12 1998 12:00AM |
| Airframe hours since last inspection | 21 |
| Airframe Hours | 6218 |
| ELT Installed | Yes |
| ELT Activated | Yes |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | HORIZON HELICOPTERS |
| Aircraft Owner Street Address | 7443 MURIETA DR |
| Aircraft Owner City | RANCHO MURIETA |
| Aircraft Owner State | CA |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 95683 |
| 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 | Yes - certificate holder |
| Other Operator of large aircraft? | No |
| Certified for Part 133 or 137 Operation | External Load |
| Operator Certificate Number | -- |
| Indicates whether an air carrier operation was scheduled or not | Unknown |
| Indicates Domestic or International Flight | Unknown |
| Operator carrying Pax/Cargo/Mail | Unknown |
| Type of Flying (Per_Bus / Primary) | Other Work Use |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | |
| Departure City | COEUR D'ALENE |
| Departure State | ID |
| Departure Country | |
| Departure Time | 750 |
| Departure Time Zone | PDT |
| Destination Same as Local Flt | crash at destination city |
| Destination Airport Code | |
| Destination City | |
| Destination State | |
| Destination Country | |
| Specific Phase of Flight | -- |
| 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 | -- |