WPR16LA081 · McDonnell Douglas Helicopter 600N
McDonnell Douglas Helicopter 600N · Accident: system/component malfunction/failure (non-power) en route
From Alturas Municipal Airport (KAAT) to Ashland Municipal Airport Sumner Parker Field (S03)
Event
- NTSB case
- WPR16LA081
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
McDonnell Douglas Helicopter 600N
- Aircraft type
- McDonnell Douglas 600
- Category
- Helicopter
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N745BW
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Alturas Municipal Airport (KAAT), Alturas, CATo Ashland Municipal Airport Sumner Parker Field (S03), Ashland, OR
- Aircraft age
- About 18 years (built 1998)
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · cruise
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- System/component malfunction/failure (non-power)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Aircraft › Aircraft propeller/rotor
- Not determined › Not determined
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
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.
Probable cause
Fatigue cracking of a main rotor blade for reasons that could not be determined based on the available information.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR16LA081
- Event ID
- 20160309X75504
- Case number
- WPR16LA081
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: c6b3d628cc5bee5e71b98d46f6f0643bc3b2ab98c75819d276aff9149a007a2c; retrieved 2026-09-16T03:12:41.480Z.