Hawker Hart in Swedish service
The Hawker Hart was a large family of pre-War British fighters, light bombers and liaison aircraft fitted with a variety of engines.
By 1932 Sweden needed a replacement for their Fokker S 6 reconnaissance aircraft. Britain demonstrated the Hart, and Sweden selected the Bristol Pegasus version to become the S 7. In 1932 Britain delivered 3 aircraft which would serve as pattern aircraft for Swedish local production. During evaluation the Swedes chose the aircraft to be repurposed as a dive bomber. Hawker engineers issued a formal objection as the Hart had not been designed for the stresses involved, but testing by the Swedes demonstrated that the airframe was suitably rugged to undertake the task. The aircraft were then redesignated as the B 4.
Various manufacturers in Sweden constructed 40 Harts using locally made Pegasus engines, designated as the B 4A. A further 2 aircraft were completed with Bristol Perseus IX engines as the B 4B.
The Swedish Harts were probably the only Harts to see combat action in WWII, with a detachment of 5 aircraft serving with the Swedish volunteer group of F19 serving in Finland during the Winter War against the Soviets.
With the end of the Winter War the Harts were withdrawn from frontline use, to fill target tugs and liaison duties. A single aircraft is preserved in the Swedish Flygvapenmuseum, painted in Winter War colours.