Sunday, May 6, 2018

McDonnell Douglas Helicopter (MDHI) 600N, N745BW: Accident occurred February 05, 2016 in Ashland, Jackson County, Oregon

The National Transportation Safety Board did not travel to the scene of this accident.

Additional Participating Entities: 
Federal Aviation Administration / Flight Standards District Office; Portland FAA-FSDO; Hillsboro, Oregon
Brim Aviation; Ashland, Oregon
MD Helicopters Inc; Mesa, Arizona
Helicopter Technology Company; Los Angeles, California

Aviation Accident Factual Report - National Transportation Safety Board:  https://app.ntsb.gov/pdf

Investigation Docket  - National Transportation Safety Board:  https://dms.ntsb.gov/pubdms

http://registry.faa.gov/N745BW

Aviation Accident Factual Report - National Transportation Safety Board 

Location: Ashland, OR
Accident Number: WPR16LA081
Date & Time: 02/05/2016, 1430 PDT
Registration: N745BW
Aircraft: MCDONNELL DOUGLAS HELICOPTER 600N
Aircraft Damage: Substantial
Defining Event: Sys/Comp malf/fail (non-power)
Injuries: 1 None
Flight Conducted Under: Part 91: General Aviation - Positioning 

On February 5, 2016, about 1430 Pacific daylight time, a McDonnell Douglas Helicopter (MDHI) 600N, N745BW, experienced a cracked main rotor blade at Ashland, Oregon. The commercial pilot was not injured; the helicopter sustained substantial damage to a main rotor blade. Brim Aviation was operating the helicopter under the provisions of 14 Code of Federal Regulations Part 91. Visual instrument meteorological conditions prevailed, and no flight plan had been filed. The cross-country positioning flight departed Alturas, California, about 1340 and was destined for Ashland.

The pilot reported that he was in one helicopter, while another pilot flew in another helicopter for the ferry flight to Ashland. Three intermediate stops were planned along the route of flight. All flight operations and characteristics had been normal, but he noted that the main rotor blades seemed minimally out of track. After departure from Alturas, he noticed a slight hop as he made an ascending 180° right turn out but stated that he had experienced worse with gusting winds and door off operations. In straight and level flight, blade track appeared to be no different than on the previous legs. During the descent into Ashland, he noticed that the hop had become more apparent when the blades were unloaded. He asked the trailing pilot to look at the rotor system for any abnormalities in flight, and the trail pilot indicated that they looked out of track. After landing, the pilot informed maintenance that the track and balance of both helicopters needed to be checked prior to the next operation. Maintenance personnel reported that there was 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.

After the operator discovered the crack, the blade was initially sent to Helicopter Technology Company for examination. The damage to the rotor blade was reported to the National Transportation Safety Board (NTSB) on March 9, 2016. 

Pilot Information

Certificate: Commercial
Age: 53, Male
Airplane Rating(s): Single-engine Land
Seat Occupied: Left
Other Aircraft Rating(s): Helicopter
Restraint Used: 4-point
Instrument Rating(s): None
Second Pilot Present: No
Instructor Rating(s): None
Toxicology Performed: No
Medical Certification: Class 2 Without Waivers/Limitations
Last FAA Medical Exam: 12/21/2015
Occupational Pilot: Yes
Last Flight Review or Equivalent: 03/01/2016
Flight Time:  9400 hours (Total, all aircraft), 3000 hours (Total, this make and model), 9400 hours (Pilot In Command, all aircraft), 115 hours (Last 90 days, all aircraft), 55 hours (Last 30 days, all aircraft), 2 hours (Last 24 hours, all aircraft)

Aircraft and Owner/Operator Information

Aircraft Manufacturer: MCDONNELL DOUGLAS HELICOPTER
Registration: N745BW
Model/Series: 600N
Aircraft Category: Helicopter
Year of Manufacture: 1998
Amateur Built: No
Airworthiness Certificate: Normal
Serial Number: RN045
Landing Gear Type: Skid;
Seats:
Date/Type of Last Inspection: 03/07/2016, 100 Hour
Certified Max Gross Wt.: 4500 lbs
Time Since Last Inspection:
Engines: 1 Turbo Shaft
Airframe Total Time: 4672 Hours as of last inspection
Engine Manufacturer: ALLISON
ELT: C126 installed, not activated
Engine Model/Series: 250-M47
Registered Owner: BRIM EQUIPMENT LEASING INC
Rated Power: 808 hp
Operator: On file
Operating Certificate(s) Held: None

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: KMIR
Observation Time: 1353 PDT
Distance from Accident Site:
Direction from Accident Site:
Lowest Cloud Condition:  Scattered / 5500 ft agl
Temperature/Dew Point: 16°C / 6°C
Lowest Ceiling: None
Visibility:  10 Miles
Wind Speed/Gusts, Direction: Calm
Visibility (RVR):  
Altimeter Setting: 30.22 inches Hg
Visibility (RVV):
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Alturas, CA (KAAT)
Type of Flight Plan Filed: None
Destination: Ashland, OR (S03)
Type of Clearance: None
Departure Time: 1340 PDT
Type of Airspace:

Airport Information

Airport: Ashland (S03)
Runway Surface Type: Asphalt
Airport Elevation: 1885 ft
Runway Surface Condition: Dry
Runway Used: 30
IFR Approach: None
Runway Length/Width: 3603 ft / 75 ft
VFR Approach/Landing: Full Stop

Wreckage and Impact Information

Crew Injuries: 1 None
Aircraft Damage: Substantial
Passenger Injuries: N/A
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 1 None
Latitude, Longitude: 42.190000, -122.660556 (est) 

Tests And Research

The damaged blade was examined by the NTSB Material's Laboratory. The blade had a time in service (TIS) of 2,013.4 hours, 11,065 torque events, and a retirement index number (RIN) of 587,640. The blade's published service life is 3,200 hours or 1 million RIN.

Visual examination revealed a visible crack on the top skin with an opposed 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.

Examination using a scanning electron microscope showed striations and other fracture features within the fatigue crack region. The initial area of origin was in the area of the trailing edge of the upper skin, and striation orientations pointed to the vicinity of the upper corner of the skin.

From the origin, the fatigue crack propagated forward in the upper skin to just past the "C" channel. At the "V" strip, the fatigue crack reinitiated at the upper aft corner of the strip and propagated forward in the upper leg of the "V" and down and forward through the lower leg of the "V." In the lower skin crack surface, additional fatigue crack propagation initiated adjacent to the lower aft corner of the "V" strip then propagated forward and aft in the skin. Two additional fatigue crack paths were discovered in the "C" channel. The complete Material Laboratory Report can be found in the public docket.

The other five main rotor blades were sent to the manufacturer for examination, and no anomalies were detected.

NTSB Identification: WPR16LA081
14 CFR Part 91: General Aviation
Accident occurred Friday, February 05, 2016 in Ashland, OR
Aircraft: MCDONNELL DOUGLAS HELICOPTER 600N, registration: N745BW
Injuries: 1 Uninjured.

This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed. NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

On February 5, 2016, about 1430 Pacific standard time, a McDonnell Douglas Helicopter (MDHI) 600N, N745BW, experienced a cracked main rotor blade at Ashland, Oregon. Brim Aviation was operating the helicopter under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91. The commercial rated pilot was not injured. The helicopter sustained substantial damage to a main rotor blade. The cross-country positioning flight departed Alturas, California, about 1340, with a planned destination of Ashland. Visual instrument meteorological conditions prevailed, and no flight plan had been filed.

The pilot reported that two helicopters departed Ogden, Utah, about 0830 with three intermediate stops including Alturas, which was the last one. All flight operations and characteristics had been normal, but he noted that the blades seemed minimally out of track. Upon departure from Alturas, he noticed a slight hop as he made an ascending right 180-degree turn out, but stated that he had experienced worse with gusting winds and door off operations. In straight and level flight, blade track appeared to be no different than on the previous legs. During descent into Ashland, he noticed that the hop had become more apparent when the blades were unloaded. He asked the trailing pilot to look at the rotor system for any abnormalities in flight, and the trail pilot indicted that they looked out of track. After landing, the pilot informed maintenance that the Track and Balance of both helicopters needed to be checked prior to the next operation. Maintenance personnel reported that there was 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. The blade had a total time of 1,942 hours.

The damage was reported to the National Transportation Safety Board on March 9, 2016.

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