Date:	Saturday 17 February 2018
Time:	12:00
Type:	AgustaWestland AW189
Owner/operator:	Bristow Helicopters opf. HM Coastguard
Registration:	G-MCGR
MSN:	92004
Year of manufacture:	2014
Engine model:	General Electric CT7-2E1
Fatalities:	Fatalities: 0 / Occupants: 4
Other fatalities:	0
Aircraft damage:	None
Category:	Serious incident
Location:	Beinn Narnain, Arrochar, Argyll and Bute, Grampian Mountains, Scotland -   United Kingdom
Phase:	Manoeuvring (airshow, firefighting, ag.ops.)
Nature:	Ambulance
Departure airport:	Glasgow-Prestwick Airport (PIK/EGPK)
Destination airport:
Investigating agency:	AAIB
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
AAIB investigation to Agusta Westland AW189, G-MCGR: Pilot became temporarily spatially disorientated in cloud at night, Beinn Narnain, Scotland, 17 February 2018.The incident was the subject of an AAIB Investigation, and the following is the summary from the AAIB Report:

"The helicopter was tasked to rescue three climbers in the area of the Beinn Narnain mountain. The flight was at night and the crew made several attempts to reach them from different directions but due to low cloud were unable to do so. On the fourth attempt, from another direction, the visual references seen through each pilot’s Night Vision Imaging System (NVIS) were lost and a turn back down the re-entrant was attempted. Due to the proximity of the ground, the pilot climbed the helicopter but lost airspeed after which the helicopter yawed to the right. The Pilot Flying (PF) attempted to use the Automatic Flight Control System (AFCS) upper modes to assist him but decoupled them because they caused the collective control lever to lower. The helicopter spot-turned through some 370° before regaining VMC on top. Control was regained and the aircraft subsequently landed. The crew liaised with the Mountain Rescue Team (MRT) who recovered the climbers on foot.

AAIB Conclusion
The incident happened when visual references were lost as the helicopter made an inadvertent entry into cloud during the valley turn. The escape heading required to exit the re-entrant was missed due to the pilot attempting to locate visual references which, due to being IMC, were not available. Use of the AFCS modes, which operated correctly, did not improve the situation but created concern at the unwanted lowering of the collective control lever, and this resulted in the AFCS modes being disengaged. The situation was being resolved, by the PF using his basic IF skills and with the assistance of the PM announcing that they were above the high ground, when the helicopter regained VMC on top of the cloud.

=Safety action=
Shortly after the incident, the operator introduced a scenario-based training exercise for all pilots that reproduced the incident during six-monthly recurrent training and testing. The training was continued with an emphasis on unusual attitude recovery

=Damage Sustained to Airframe=
Per the above AAIB report "None"

Beinn Narnain (sometimes anglicised as Ben Narnain) is a 926 metre (3,038 ft) mountain in the southern Highlands of Scotland, near Arrochar. It forms part of a group of hills known (unofficially) as the Arrochar Alps, and is a Munro. The name Beinn Narnain means "hill of notches", and describes the mountain's notched profile.

1. AAIB Report: https://assets.publishing.service.gov.uk/media/5f463c9dd3bf7f69a50a1a40/Agusta_Westland_AW189__G-MCGR_09-19.pdf
2. https://archive.news.stv.tv/west-central/1440022-helicopter-rescue-mission-aborted-due-to-loss-of-control.html
3. https://www.helis.com/database/cn/41439/
4. https://www.pprune.org/rotorheads/624634-loss-visual-references.html
5. https://en.wikipedia.org/wiki/Beinn_Narnain

G-MCGR: AgustaWestland AW189 at Glasgow Prestwick Airport (PIK/EGPK) 26 August 2017

Date/time	Contributor	Updates
18-Aug-2019 09:09	harro	Added
20-Jun-2024 17:56	Dr. John Smith	Updated [Time, Operator, Location, Source, Embed code, Narrative, Category, ]