- Date
- July 6, 1986, 08:20 local (15:20 UTC)
- Place
- Valencia, CA
- Injuries
- 1 serious
- Damage
- Substantial damage
- Phase of flight
- Maneuvering
- Aircraft
- N51856Texas Helicopter OH-13H/M
- Weather
- Visual (VMC) · Day
- Status
- Completed
- Report
- Approved by Office Director
- FAA report
- 19860706034439A
- Case key
- 25206
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
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 pilot reported that he heard a loud bang and grinding noise from the engine/main transmission area while on a swath run. He stated that the main rotor RPM decayed immediately after he heard the noise. As the helicopter descended to about 50 feet above the ground the pilot said he flared for the touchdown. The helicopter landed hard severing the skids, tail and spray booms. The pilot said the engine continued to run after the accident, however, the rotor was not turning. Post accident inspection of the transmission revealed a massive overload failure of the lower pinion gear assembly. Bogus pinion gears were found installed in the transmission.
Aircraft
- Registration
- N51856
- Reported as
- Texas Helicopter OH-13H/M
- Category
- Helicopter
- Serial number
- 78-023
- Airframe hours
- 2,743
- Engine
- Lycoming VO-435A/F, 260 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Aerial application · Part 137
- Registered owner
- Roy G. Cox
- Airworthiness certificate
- Special, Restricted (Special)
- Last inspection
- 100 hour · June 2, 1986 · 47 hours before
- Departed
- Valencia, CA
- Airport
- VNY · Van Nuys
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
- 39
- Certificate
- Commercial
- Medical
- Class 2, Valid Medical--no waivers/lim.
- Seat
- Center
- Flight hours
- 8,850 total · 1,500 in this make and model · 7,858 as pilot in command · 120 in the last 90 days · 40 in the last 30 days · 2 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- Calm
- Visibility
- 7 statute miles
- Lowest ceiling
- 2,000 ft overcast
- Temperature
- 61 °F, dew point 61 °F
- Altimeter
- 30.00 inHg
- Observed at
- VNY, 10 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.
Other investigations on N51856 · 1
Matched to the same aircraft by N-number and date.