Airbus/Eurocopter AS 350 B3 N356EV

Summary

On 11 June 2014 at about 19:40 local time, a Airbus/Eurocopter AS 350 B3 registered N356EV, operated by Can See Aviation LLC, was involved in an accident near Anchorage, Alaska, United States. 3 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

11 June 2014 at 19:40

Classification

Accident

Location

Anchorage, Alaska, United States

Nearest airport

Merril Field (MRI)

Coordinates

61.2133, -149.8445

Aircraft

Airbus/Eurocopter AS 350 B3

Registration

N356EV

Category

Helicopter

Year built

2002

Engines

1

Operator

Can See Aviation LLC

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Anchorage → Gulkana

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ANC14LA041

Nobody was injured.

The pilot’s improper engine start procedure, which resulted in an overspeed of the engine and main rotor drive system.

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

Read the full NTSB narrative

The pilot had been hired to ferry the recently-purchased turbine-powered helicopter to the new owner’s facility and to provide the second pilot, the new owner, with transition flight training while en route. Unable to start the helicopter, despite believing he was following the correct procedures, the first pilot enlisted help from another pilot and eventually started the helicopters engine. While the helicopter was operating at flight-idle, the yellow "TWT.GRIP" light illuminated on the annunciator panel, and the first pilot instructed the second pilot to slowly advance the collective-mounted throttle twist grip to the open position until the light went out. As the second pilot advanced the throttle, the engine speed immediately increased to a high rpm and the helicopter began to shake violently. It subsequently rotated about 240° to the left, sustaining substantial damage to the tail boom and main rotor drive system. Examination of the engine and full authority digital engine control (FADEC) systems revealed no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. The accident pilot reported that he had extensive experience in helicopters that had two-channel FADEC systems, but did not recall how much time he had in helicopters with single-channel FADEC systems. The accident helicopter was equipped with a single-channel FADEC system, which required a different starting procedure than an engine with a two-channel FADEC. Given the absence of mechanical anomalies and the pilot’s unfamiliarity with the single-channel FADEC system, it is likely that he used the incorrect start and run-up procedure, which resulted in an inadvertent overspeed of the helicopter's engine and main rotor drive system.

Quoted verbatim from the NTSB record.