Aircraft Accident/Incident Report

Compton, California 90220
Tuesady, March 14, 2000 19:11 PST

NTSB Narrative Summary Released at Completion of Accident

The helicopter hit a trailer and the ground during an autorotation precipitated by pilot perceived malfunctions in the electrical and hydraulic systems during cruise. A city police department operated the helicopter for law enforcement patrol missions. After exiting an orbit around a ground situation, the crew saw the low rotor rpm warning light flash on, then back off, then on again. Normal rotor and engine rpm was shown on the tach. They were only 3 miles from their airport base and the pilot decided to return there. The low rotor warning light began to flash on and off, with an increasing frequency until it was steady. Suddenly all the cockpit warning and caution lights illuminated, both on the eyebrow panel and center pedestal panel. The hydraulic system also turned off and the pilot had to resort to manual force on the flight controls. The pilot checked the engine and rotor gages and noted that the rotor needle was pointing off scale high; however, neither crewmember heard any change in the engine and rotor sounds. The observer reported that he believed they lost their radios and exterior lights at this time and also said that the engine and rotor tach needles were married together at 100 percent until the autorotation. The pilot was on an extended final approach to the runway and helicopter control was becoming difficult. Suddenly, an airplane appeared on base leg to the runway and the pilot had to maneuver to avoid a collision. With the control difficulties and uncertainty about what was happening to the helicopter, the pilot decided to autorotate to a clear area in a schoolyard. The night sun spotlight failed during the autorotation and the pilot cleared a building but could not avoid a parked trailer that he had not seen before. The helicopter collided with the trailer, then the ground, and rolled over. The hydraulic system solenoid valve is electrically operated and it takes electrical power to close the valve and turn off the hydraulics; the valve fails to the open position when electrical power is lost. Post accident testing of the hydraulic system found normal operation. The complete electrical system wiring was traced from the generator and battery to the ground points on each circuit, with no discrepancies found. The main rotor tach drive and the cockpit gauge were functionally tested. No like events were found during searches of the historical records for the US Army, Bell Helicopters, or in the FAA SDR database. Bell Helicopter opined that an almost complete electrical system voltage spike/surge simultaneously in a large number of circuits would be required to replicate the event as described by the crew.

NTSB Probable Cause Narrative

An undetermined electrical system voltage surge.

Event Information

Type of Event Accident
Event Date 3/14/2000
Event Day of the Week Tuesday
Time of Event 1911
Event Time Zone Pacific Standard Time
Event City COMPTON
Event Country --
Zipcode of the event site 90220
Event Date Year 2000
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 Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 1953 Pacific Standard Time
Direction of event from weather observation facility (degrees) 275
Weather Observation Facility ID HHR
Elevation of weather observation facility 57
Distance of event from weather observation facility (units?) 7
Time Zone of the weather observation PST
Lighting Conditions Night/Bright
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) 4
Air Temperature at event time (in degrees celsius) 61
Dew Point at event time (in degress fahrenheit) 52
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) 29
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury Minor
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor 2
Injury Total None --
Injury Total Serious --
Injury Total All 2
Investigating Agency NTSB
NTSB Docket Number (internal use) 10273
NTSB Notification Source --
NTSB Notification Date Mar 14 2000 12:00AM
NTSB Notification Time 1942
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Jul 30 2001 11:11AM
User who most recently changed record MONR
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N911JN
NTSB Number LAX00GA114
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Destroyed
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Bell
Aircraft Model OH-58C
Aircraft Series Identifier OH-58C
Aircraft Serial Number 68-16751
Certified Max Gross Weight 3200
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 Continuous Airworthiness
Date of Last Inspection Feb 28 2000 12:00AM
Airframe hours since last inspection 77
Airframe Hours 7126
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Street Address 301 S. WILLOWBROOK AVENUE
Aircraft Owner City COMPTON
Aircraft Owner State CA
Aircraft Owner Country
Aircraft Owner Zipcode 90220
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 --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) Public Use
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code CPM
Departure City
Departure State
Departure Country
Departure Time 1730
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 Cruise
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jul 16 2001 8:28AM
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 --