- Date
- May 12, 1993, 07:15 local (14:15 UTC)
- Place
- Anatone, WA
- Injuries
- 1 fatal
- Damage
- Destroyed
- Phase of flight
- Maneuvering
- Aircraft
- N846DKaman HH-43F
- Weather
- Visual (VMC) · Day
- Status
- Completed · report June 22, 1994
- Report
- Approved by Office Director
- FAA report
- 19930512013379A
- Case key
- 43019
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
Fatigue failure of the rotor transmission drive system, resulting from the improper certification/approval of the aircraft modification by the federal aviation administration.
Sequence of events
NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.
Analysis
The converted military helicopter was in a hover lifting an external load of logs when the main rotor pylons separated in flight, resulting in an uncontrolled inverted descent into the ground. On-scene examination revealed that the transmission rotor input gear shaft, p/n K774515-5F, had fractured. Safety board metallurgical examination showed that the fracture was characteristic of fatigue failure, and indicated repetitive high loads. The FAA type-certificate, based on military configuration, lists the approved engine as 1100 shp, and the external load limit as 2,300 lbs. The FAA had approved installation of a 1400 shp engine, and operations with an increased external load limit of 4,000 lbs.
Aircraft
- Registration
- N846D
- Reported as
- Kaman HH-43F
- Category
- Helicopter
- Serial number
- 58-1846
- Airframe hours
- 7,266
- Engine
- Lycoming T53-L-13B, 1,400 horsepower, turbo shaft
- Damage
- Destroyed
- Fire
- On-Ground
- Flight
- Other work use · Part 133
- Operator
- Woody Contracting, Inc
- Registered owner
- Robert & Sharon Woody
- Airworthiness certificate
- Special, Restricted (Special)
- Last inspection
- 100 hour · April 27, 1993 · 42 hours before
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 45
- Certificates
- Commercial, Flight instructor
- Instrument ratings
- Helicopter
- Medical
- Class 2, Valid Medical--no waivers/lim.
- Seat
- Left
- Toxicology
- Performed
- Flight hours
- 18,970 total · 3,051 in this make and model · 18,051 as pilot in command · 344 in the last 90 days · 113 in the last 30 days
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 130° at 8 knots
- Visibility
- 30 statute miles
- Lowest ceiling
- None
- Temperature
- 64 °F, dew point 46 °F
- Altimeter
- 29.00 inHg
- Observed at
- LWS, 26 nm away
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.