Aircraft Incident/Accident Report


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

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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 EventAccident 
Event Date3/14/2000 
Event Day of the WeekTuesday 
Time of Event1911 
Event Time ZonePacific Standard Time 
Event CityCOMPTON  
Event StateCALIFORNIA 
Event Country-- 
Zipcode of the event site90220  
Event Date Year2000 
Event Date Month
MidAir Collision IndicatorNo 
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 airportOff Airport/Airstrip 
Distance from airport in statute miles-- 
Degrees magnetic from airport-- 
Airport Elevation-- 
Weather Briefing CompletenessUnknown 
Investigator's weather sourceWeather Observation Facility 
Time of the weather observation1953 Pacific Standard Time 
Direction of event from weather observation facility (degrees)275 
Weather Observation Facility IDHHR  
Elevation of weather observation facility57 
Distance of event from weather observation facility (units?)
Time Zone of the weather observationPST 
Lighting ConditionsNight/Bright 
Lowest Ceiling Height
Lowest Non-Ceiling Height
Sky/Lowest/Cloud ConditionsClear 
Sky Condition for Lowest CeilingNone 
Visibility Runway Visual Range (Feet)
Visibility Runway Visual Value (Statute Miles)
Visibility (Statute Miles)
Air Temperature at event time (in degrees celsius)61 
Dew Point at event time (in degress fahrenheit)52 
Wind Direction (degrees magnetic)
Variable Wind IndicatorUnknown 
Wind Speed (knots)
Wind Velocity Indicator Calm 
Wind Gust IndicatorNot Gusting 
Wind Gust (knots)
Altimeter Setting at event time (in. Hg) 29 
Density Altitude (feet)-- 
Intensity of PrecipitationUnknown 
METAR weather report -- 
Event Highest InjuryMinor 
On Ground, Fatal Injuries
On Ground, Minor Injuries
On Ground, Serious Injuries
Injury Total Fatal-- 
Injury Total Minor
Injury Total None-- 
Injury Total Serious-- 
Injury Total All
Investigating AgencyNTSB 
NTSB Docket Number (internal use)10273 
NTSB Notification Source-- 
NTSB Notification DateMar 14 2000 12:00AM 
NTSB Notification Time1942 
Fiche Number and/or location -used to find docket informationIMAGE 
Date of most recent change to recordJul 30 2001 11:11AM 
User who most recently changed recordMONR  
Basic weather conditionsVisual Meteorological Cond 
FAA District Office-- 
Aircraft Involved
Aircraft #1
Aircraft Registration NumberN911JN 
NTSB NumberLAX00GA114  
Missing Aircraft Indicator
Federal Aviation Reg. PartPart 91: General Aviation 
Type of Flight Plan filedNone 
Flight plan Was Activated?-- 
DamageDestroyed 
Aircraft FireNone 
Aircraft ExplosionNone 
Aircraft Manufacturer's Full NameBell  
Aircraft ModelOH-58C  
Aircraft Series IdentifierOH-58C  
Aircraft Serial Number68-16751  
Certified Max Gross Weight3200 
Aircraft CategoryHelicopter 
Aircraft Registration ClassU.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
Number of Engines
Fixed gear or retractable gearFixed 
Aircraft, Type of Last InspectionContinuous Airworthiness 
Date of Last InspectionFeb 28 2000 12:00AM 
Airframe hours since last inspection77 
Airframe Hours7126 
ELT InstalledNo 
ELT ActivatedUnknown 
ELT Aided Location of Event SiteUnknown 
ELT Type-- 
Aircraft Owner NameCOMPTON POLICE DEPARTMENT  
Aircraft Owner Street Address301 S. WILLOWBROOK AVENUE  
Aircraft Owner CityCOMPTON  
Aircraft Owner StateCA 
Aircraft Owner Country  
Aircraft Owner Zipcode90220  
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 certificateNone 
Other Operator of large aircraft?No 
Certified for Part 133 or 137 OperationUnknown 
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 BoardNo 
Departure Point Same as EventYes 
Departure Airport CodeCPM  
Departure City  
Departure State  
Departure Country  
Departure Time1730 
Departure Time ZonePDT 
Destination Same as Local Fltdest & departure same, accident can occur anywhere 
Destination Airport Code  
Destination City  
Destination State  
Destination Country  
Specific Phase of FlightCruise 
Report sent to ICAO?-- 
Evacuation occurred-- 
Date of most recent change to recordJul 16 2001 8:28AM 
User who most recently changed recorddbo  
Since inspection or accident-- 
Event Location Runway Number and Location0  
Runway Length-- 
Runway Width-- 
Sight Seeing flightNo 
Air Medical FlightNo 
Medical Flight--