Bell 407 N407HC

Summary

On 31 May 2013 at about 03:07 local time, a Bell 407 registered N407HC, operated by Howard County Police Department, was involved in an accident near Columbia, Maryland, United States. 4 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

31 May 2013 at 03:07

Classification

Accident

Location

Columbia, Maryland, United States

Coordinates

39.2161, -76.8711

Aircraft

Bell 407

Registration

N407HC

Category

Helicopter

Year built

2006

Engines

1

Operator

Howard County Police Department

Operating rule

Public Use

Phase of flight

Not recorded

Route

Fort Meade → Fort Meade

Aircraft damage

Substantial

Weather

VMC

Light

Night/Dark

NTSB number

ERA13TA261

Nobody was injured.

The short circuit failure of a tantalum capacitor, internal to the engine’s electronic control unit, resulting in an uncommanded shutdown of the engine in flight.

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

Read the full NTSB narrative

During a routine police patrol flight, while about 600 feet above the ground, the helicopter suddenly yawed to the left and the red "ENGINE OUT" warning light illuminated. The engine lost all power and the pilot performed an autorotation landing on a nearby football field. While avoiding obstacles, the helicopter landed hard, resulting in substantial damage to the airframe. A postaccident examination of the engine revealed no damage or obvious reason for the loss of power. The engine's electronic control unit (ECU) was removed and was shipped to the manufacturer's facility for evaluation and testing. The examination of the ECU revealed that the engine was operating normally until an unexpected activation of the full authority digital electronic control overspeed protection system fuel reduction solenoid, which is internal to the ECU, resulting in an uncommanded in-flight engine shutdown. A subsequent ECU functional review confirmed that a short circuit failure of a tantalum capacitor was the source of the ECU malfunction. After the accident, Bell Helicopter issued an Alert Service Bulletin and Rolls-Royce issued an accompanying Commercial Engine Bulletin that included the installation of an overspeed adapter to reduce the likelihood of a false overspeed activation.

Quoted verbatim from the NTSB record.