Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Baker, Oregon 97814
Monday, March 30, 1998 9:10 PST
NTSB Narrative Summary Released at Completion of Accident
The pilot stated that he had lifted off from a road in open terrain so that a truck could get by. He stated that the lift-off was smooth. He noticed some shaking when he began forward flight. He increased the load on the rotor disk and the shaking became so violent that he couldn't see the ground. He dropped the collective and reached the ground. He said that the only way he could describe the situations was that 'it was like being in the spin cycle of a washing machine when all of the weight is on one side.' The helicopter had recently been imported to the US from Canada, and recertified with a US airworthiness certificate. The helicopter had been involved in a hard-landing accident in Japan on June 10, 1994. Damage to the aircraft at that time included the left skid, deformation of the fuselage and twisting of the tail boom. All three main-rotor blades had terrain impact The helicopter was later exported from Japan to Canada, where the importee stated that it was received in a repaired condition. No reference to the accident or its required repair was made in the Canadian maintenance or journey logs. No record was found for accomplishment of an inspection, as outlined in the Enstrom Maintenance Manual, for main rotor blade strike or hard landing inspections. The Safety Board materials laboratory inspected fragments from the steel tube pylon assembly, consisting of pieces of steel tubing that are welded to each other to form a frame structure for the helicopter. The steel tubes provide reinforcement for the four attachment points of the main transmission and other attachment points for the engine. Two of the steel tubes exhibited fatigue cracking, and completely separated during operation of the helicopter.
NTSB Probable Cause Narrative
Fatigue failure of the steel tubing pylon structure. Factors include inadequate inspection by maintenance personnel of damage after a previous accident.
Event Information
| Type of Event | Accident |
| Event Date | 3/30/1998 |
| Event Day of the Week | Monday |
| Time of Event | 910 |
| Event Time Zone | Pacific Standard Time |
| Event City | BAKER |
| Event State | OREGON |
| Event Country | -- |
| Zipcode of the event site | 97814 |
| Event Date Year | 1998 |
| Event Date Month | 3 |
| 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 | Weather Observation Facility |
| Time of the weather observation | 850 Pacific Daylight Time |
| Direction of event from weather observation facility (degrees) | 0 |
| Weather Observation Facility ID | BKE |
| Elevation of weather observation facility | 0 |
| Distance of event from weather observation facility (units?) | 0 |
| Time Zone of the weather observation | PDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 0 |
| Lowest Non-Ceiling Height | 20000 |
| 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) | 40 |
| Air Temperature at event time (in degrees celsius) | 8 |
| Dew Point at event time (in degress fahrenheit) | 6 |
| Wind Direction (degrees magnetic) | 0 |
| Variable Wind Indicator | Variable |
| Wind Speed (knots) | 3 |
| 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) | 1228 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Mar 30 1998 12:00AM |
| NTSB Notification Time | 1523 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Dec 11 2000 10:58AM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N171HH |
| NTSB Number | SEA98FA055 |
| 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 | Enstrom |
| Aircraft Model | F28F |
| Aircraft Series Identifier | F28F |
| Aircraft Serial Number | 758 |
| Certified Max Gross Weight | 2600 |
| 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 | 3 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | Mar 18 1998 12:00AM |
| Airframe hours since last inspection | 39 |
| Airframe Hours | 433 |
| ELT Installed | Yes |
| ELT Activated | Yes |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | HERMAN'S HELICOPTERS |
| Aircraft Owner Street Address | HHC 82 BOX 208 |
| Aircraft Owner City | KIMBERLY |
| Aircraft Owner State | OR |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 97484 |
| 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 | 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) | Positioning |
| Second Pilot on Board | No |
| Departure Point Same as Event | Yes |
| Departure Airport Code | |
| Departure City | |
| Departure State | |
| Departure Country | |
| Departure Time | 945 |
| Departure Time Zone | PST |
| 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 | Maneuvering |
| 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 | -- |