08/31/2012. Remarks by Johan Visschedijk: "The aircraft was registered to Sikorsky as N411A on April 27, 1955, ten weeks later, July 6, the registration was cancelled as the aircraft was sold to Sweden.

Sikorsky S-55 (SE-HBB) (Johan Visschedijk Collection)

It became the second S-55 to be used by the Swedish company Osterman Aero AS, registered as SE-HBB. (The first S-55 for Osterman, SE-HBA c/n 55759, was delivered a year earlier, July 22, 1954.)

Bell 47B (SE-HAA) (Johan Visschedijk Collection)

Osterman was formed as Aero Services AB in 1943, and became an Auster dealer in late 1945. The company imported the first helicopter to Sweden in November 1946 (Bell 47B, SE-HAA), subsequently it was renamed Osterman Aero AS and it became the Bell dealer for Scandinavia, while in 1947 it became an agent for the Republic Seabee. In the 1950s the company focused on helicopter activities (transport, training, maintenance) and in 1981 it was renamed Osterman Helicopter AB and presently Osterman states it is the world's oldest helicopter company."