Van Nuys Airport
Aircraft Accident/Incident Report

Valencia, California 91355
Sunday, July 6, 1986 8:20 PDT

NTSB Narrative Summary Released at Completion of Accident

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.

NTSB Probable Cause Narrative

Not Yet Reported

Event Information

Type of Event Accident
Event Date 7/6/1986
Event Day of the Week Sunday
Time of Event 820
Event Time Zone Pacific Daylight Time
Event City VALENCIA
Event State CALIFORNIA
Event Country --
Zipcode of the event site 91355
Event Date Year 1986
Event Date Month 7
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport VAN NUYS
Event Location Nearest Airport ID VNY
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles 10
Degrees magnetic from airport 325
Airport Elevation 0
Weather Briefing Completeness Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 746 Pacific Daylight Time
Direction of event from weather observation facility (degrees) 145
Weather Observation Facility ID VNY
Elevation of weather observation facility 0
Distance of event from weather observation facility (units?) 10
Time Zone of the weather observation PDT
Lighting Conditions Day
Lowest Ceiling Height 2000
Lowest Non-Ceiling Height 1000
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling Overcast
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 7
Air Temperature at event time (in degrees celsius) 16
Dew Point at event time (in degress fahrenheit) 16
Wind Direction (degrees magnetic) 0
Variable Wind Indicator Unknown
Wind Speed (knots) 0
Wind Velocity Indicator Calm
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
Density Altitude (feet) 1200
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury Serious
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor --
Injury Total None --
Injury Total Serious 1
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 2276
NTSB Notification Source --
NTSB Notification Date Jul 6 1986 12:00AM
NTSB Notification Time 1150
Fiche Number and/or location -used to find docket information 32932
Date of most recent change to record Jan 2 2001 9:14AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N51856
NTSB Number LAX86LA283
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 137: Agricultural
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name TEXAS HELICOPTER
Aircraft Model OH-13H/M
Aircraft Series Identifier OH-13H/M
Aircraft Serial Number 78-023
Certified Max Gross Weight 2450
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 1
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Jun 2 1986 12:00AM
Airframe hours since last inspection 47
Airframe Hours 2743
ELT Installed No
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name ROY G. COX
Aircraft Owner Street Address PO BOX 1022
Aircraft Owner City RIALTO
Aircraft Owner State CA
Aircraft Owner Country
Aircraft Owner Zipcode 92376
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 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 Unknown
Indicates Domestic or International Flight Unknown
Operator carrying Pax/Cargo/Mail Unknown
Type of Flying (Per_Bus / Primary) Aerial Application
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code
Departure City VALENCIA
Departure State CA
Departure Country
Departure Time 800
Departure Time Zone PDT
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 Landing
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:36AM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 0
Runway Length 0
Runway Width 0
Sight Seeing flight No
Air Medical Flight No
Medical Flight --