Date:	Friday 11 March 2016
Time:	13:18 LT
Type:	Eurocopter AS 365N3 Dauphin 2
Owner/operator:	National Airborne Service Corps (NASC)
Registration:	NA-107
MSN:	6556
Year of manufacture:	1999
Fatalities:	Fatalities: 2 / Occupants: 5
Other fatalities:	0
Aircraft damage:	Destroyed
Category:	Accident
Location:	0.3nm off Shimen District, New Taipei -   Taiwan
Phase:	Manoeuvring (airshow, firefighting, ag.ops.)
Nature:	Passenger - Non-Scheduled/charter/Air Taxi
Departure airport:	Song Shan Airport
Destination airport:	Song Shan Airport
Investigating agency:	ASC
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
The helicopter crashed while supporting a salvage operation. Two crew members died from the injuries sustained. The three other POB were seriously injured.
Video shows the aircraft in the hover at c100ft before yawing rapidly, turning through 360 degrees several times and impacting the sea.
The helicopter was dispatched to take an engineer and two Coast Guard (CGA-SSC) specialists to a Taiwan-registered 13,500-ton freighter, that ran aground 10 March 2016 about 300 meters off the coast, to see how much oil had been leaked by the ship.
All 21 of the freighter's crew members were earlier airlifted to safety after they abandoned ship.

The GPS system indicated that the aircraft began yawing towards the left at 1317:44. Before the aircraft yawed
towards the left, the pilot said, "mission abort, mission abort". Four seconds later (1317:48), the aircraft began to turn drastically. According to the copilot's interview, the aircraft was shaking in all directions as the aircraft drastically spun towards the left. The copilot also heard the pilot saying, "What is happening to the aircraft?" As the spinning speed of the aircraft accelerates, the CGA-SSC member performing the hoisting mission was thrown up by the great centrifugal force generated by the spinning motions and aircraft altitude changed. After the CGA-SSC member impacted the main rotor and crashing into the sea, the aircraft plummeted on the sea surface to the left of the cargo ship at 1317:59 with a right roll in an easterly direction.

Findings related to probable causes:
The available evidence indicated that maintenance performed the tail gear box control rod bearing inspection through the periodic check in accordance with the Alert Service Bulletin AS365-05.00.61R4 and all successive measurements were within the criteria. The maintenance personnel did not detect the bearing was worn, the tactile/sensitive manual axial play check is mainly based on the judgment of the operator and therefore subjective to detect manually.
The bearing wear continued, which spalled off the inner ring shoulder, completely detached the outer ring, and eventually led to the malfunction of pitch control in the tail rotor bearing. Due to the failure of the tail rotor pitch function, the pilot could not control the flight direction. Flying at a low altitude and driven by large horsepower, the main rotor was damaged from impact. The pilot could no longer perform relevant emergency procedures according to the flight manual and eventually lost control and crashed into the sea.

There were 14 safety recommendations issued.

https://www.asc.gov.tw/main_en/docDetail.aspx?uid=318&pid=318&docid=794
https://www.taiwannews.com.tw/en/news/2893639
http://focustaiwan.tw/news/asoc/201603110016.aspx (registration source)
http://www.airliners.net/photo/Taiwan---National/Eurocopter-AS-365N-3-Dauphin/2712018/M
https://www.asc.gov.tw/main_en/docDetail.aspx?uid=318&pid=318&docid=745
http://www.taipeitimes.com/News/front/archives/2016/03/12/2003641375
https://www.bea.aero/en/investigation-reports/notified-events/detail/event/perte-de-controle-en-lacet-collision-avec-la-surface-de-leau-lors-dune-operation-de-treuillage/
https://www.flightglobal.com/news/articles/taiwan-as365-crash-caused-by-maintenance-oversights-436070/
http://aerossurance.com/helicopters/trpc-loss-hoisting-as365/
https://www.asc.gov.tw/main_en/docaccident.aspx?acd_no=208&uid=343&pid=296

#OTD 2016: The undetected failure of a TR pitch change bearing while hoisting. We delve into the ASC's final report (only published in full in Chinese). https://t.co/9So0koBcUc #aviationsafety #flightsafety #helicopter #accident #sar #searchandrescue #airworthiness pic.twitter.com/NQdu3eNJw3

— Aerossurance (@Aerossurance) March 11, 2021

Date/time	Contributor	Updates
11-Mar-2016 08:39	gerard57	Added
11-Mar-2016 13:14	Aerossurance	Updated [Time, Aircraft type, Nature, Source, Narrative, ]
11-Mar-2016 13:20	Aerossurance	Updated [Phase, Embed code, Narrative, ]
11-Mar-2016 14:14	franka	Updated [Registration, Source, ]
11-Mar-2016 15:08	Iceman 29	Updated [Cn, Source, Embed code, ]
12-Mar-2016 15:54	TB	Updated [Aircraft type, Location, Narrative, ]
12-Mar-2016 15:57	Black Typhoon	Updated [Time, Aircraft type, ]
12-Mar-2016 16:12	TB	Updated [Aircraft type, Location, ]
12-Mar-2016 17:02	Aerossurance	Updated [Operator, Location, Departure airport, Source, ]
12-Mar-2016 17:11	Aerossurance	Updated [Operator, ]
14-Mar-2016 09:36	Aerossurance	Updated [Source, ]
04-May-2016 12:57	Aerossurance	Updated [Source, Narrative, ]
08-Apr-2017 06:22	harro	Updated [Source, Narrative, ]
10-Apr-2017 17:24	Aerossurance	Updated [Source, Narrative, ]
20-Apr-2017 20:33	Aerossurance	Updated [Location, Source, ]
11-Mar-2021 07:54	Aerossurance	Updated [Embed code, ]
11-Mar-2021 07:55	Aerossurance	Updated [Destination airport, Embed code, ]
05-Jun-2021 14:29	harro	Updated [Accident report, ]