Photo from: Juhani Riekkola / Museum Centre Vapriikki (Tampere)

Another mail helicopter experiment - a Swedish chopper landing of the roof of the Helsinki main post office. The Finnish parliament is visible on the left, the tower of the National Museum on the right. Photo from: Finnish Heritage Agency

Before acquiring any helicopters of their own, the Swedish armed forces held extensive trials with Ostermans Aero's Bell 47s and S-55s - fortunately for the company which had lost a lot of money using the two S-55s on a Malmö - Copenhagen passenger shuttle service in June and July 1955. Photo from: Sjöhistoriska Museet

'On land, at sea and in the air' slogan. Built in 1947 and shipped to Sweden with three other Seabees for AB Hans Osterman. Used by Ostermans Aero and other owners until about 1965, but with several accidents and long downtimes. Photo from: Länsmuseet Gävleborg

This was apparently the very first helicopter exported by Bell, making Ostermans the first commercial helicopter operator outside the USA in February 1947. It was at first unofficially marked SE-AZT. As in other countries, the helicopter was seen as a possible mail vehicle and one of the first cargoes was a few letters delivered to a lighthouse keeper. SE-HAA ditched and sank in the harbour of Stockholm on 20 May 1949. Photo from: Tekniska Museet