McDonnell Douglas 600N N745BW

Summary

On 5 February 2016 at about 21:30 local time, a McDonnell Douglas 600N registered N745BW was involved in an accident near Ashland, Oregon, United States. One person was 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

5 February 2016 at 21:30

Classification

Accident

Location

Ashland, Oregon, United States

Nearest airport

Ashland (S03)

Coordinates

42.1900, -122.6606

Aircraft

McDonnell Douglas 600N

Registration

N745BW

Category

Helicopter

Year built

1998

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Positioning

Phase of flight

Not recorded

Route

Alturas → Ashland

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR16LA081

Nobody was injured.

Fatigue cracking of a main rotor blade for reasons that could not be determined based on the available information.

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

Read the full NTSB narrative

The commercial pilot reported that, during a cross-country helicopter flight, the main rotor blades seemed minimally out of track. After departing on the last leg of the flight, he noticed a slight "hop" as he made an ascending 180° right turn, but later stated that he had experienced worse with gusting winds and door-off operations. In straight and level flight, the blade track appeared to be no different than on the previous legs. During the descent toward the destination, he noticed that the hop became more apparent when the blades were unloaded. Maintenance personnel subsequently found a crack in one main rotor blade from the trailing edge forward to the spar at a point midspan near the beginning of the trim tab. Examination revealed a visible crack on the top skin, with an opposing crack on the bottom skin. The crack surfaces were flat and light grey with features indicative of fatigue cracking from the trailing edges of the upper and lower skins forward to an internal "C" channel. No gross mechanical damage was visible, and abrasions visible after stripping paint from the blade appeared to be too small to initiate the fatigue crack. The blade had been in service for about 2/3 of its service hour life and more than half of its cycle life at the time of discovery. The reason for crack initiation could not be determined.  

Quoted verbatim from the NTSB record.