Bell OH-58A N911RN

Summary

On 6 November 1999 at about 17:50 local time, a Bell OH-58A registered N911RN was involved in an accident near La Puente, California, United States. One person was on board and one had minor injuries. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

6 November 1999 at 17:50

Classification

Accident

Location

La Puente, California, United States

Coordinates

34.0391, -117.9807

Aircraft

Bell OH-58A

Registration

N911RN

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Public Use

Phase of flight

Not recorded

Route

El Monte → Industry

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

LAX00TA030

1 person had minor injuries.

A loss of engine power for undetermined reasons.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

Following a loss of engine power, the helicopter slid forward on the ground and the main rotor blades severed a power pole during an autorotation to a city street. While in cruise flight at 100 knots and 600 feet above ground level, the N1 engine speed began to bleed off. The pilot modulated the throttle and attempted other corrective action. However, the N1 and N2 speeds continued to bleed off and the pilot began a right turn for a 180-degree autorotation. A vehicle moved onto the road where he planned to land. The pilot attempted to land on a traffic island, but the helicopter continued on into the power pole. Following a temporary loss of power in August, maintenance technicians had removed and replaced the fuel pump and fuel control units. The helicopter accumulated about 50 hours between this maintenance and the accident. A 50-hour inspection was completed just before this flight. All connections for the pneumatic, oil supply, and scavenge lines were secure. The oil screen was clean. Fuel was present in all the fuel lines and a vacuum check on the fuel system revealed no discrepancies. The fuel spray nozzle was sooty but clear. The electric fuel pump discharged over 1 gallon of fuel in 1 minute, and investigators pumped out a total of 30 gallons of fuel from the helicopter's fuel tank. The engine driven fuel pump filter was absent of contaminants. The airframe external fuel filter contained visible contaminants, but not enough to prevent normal engine operation. The engine and transmission chip detectors were clean. The compressor, N1 turbine, and N2 turbine turned freely when manually rotated. There were no leaks in the PG governor pressure lines. The engine was run in a test cell and tested satisfactorily through accelerations, decelerations, and horsepower checks in all parameters in accordance with the Allison overhaul manual.

Quoted verbatim from the NTSB record.