Piasecki HUP-3 (Retriever)
"As for that clattery Piasecki thing..."
This aircraft arrived in US Army colours at RCNAS Shearwater in Dartmouth NS in May 1954. After being given a paint job it eventually became part of HU-21 (Helicopter Utility Sqdn.).
The photograph was possibly taken whilst this aircraft, as part of HU-21 Detachment 2, was operating from the Arctic Patrol Vessel HMCS "Labrador" which in 1955 was supporting construction of the Canadian/US DEW line in Northern Canada.
Originally it was numbered 947 but on 1/6/55, when "Labrador" sailed from Halifax for Hudson Bay/Foxe Basin, the number was changed to 247. It remained with the ship together with two Bell HTL-4 machines until late November and operated more or less continuously in that period sometimes in very bad weather conditions. "Clattery" it may have been but it was a very good helicopter.