Frank Whittle runs the first British jet engine. 26 April 1937 Bombardment of Guernica. About 1600 people were killed. The Fairey Battle light bomber enters RAF service. His place in the Spitfire development team is taken by Joseph 'Joe' Smith.
Japan invades China.
The Messerschmitt Bf 109B appears in Spain. 17 August 1937 First flight of a radar installed in an aircraft. This is an experimental ASV radar. 2 September 1937 First flight of the Grumman XF4F-2, the prototype of the F4F Wildcat carrier fighter. 19 September 1937 Ejector exhaust are fitted to K5054, replacing the original flush exhausts.