High Quality Content by WIKIPEDIA articles! The Gloster Gamecock was a biplane fighter of the Royal Air Force, a development of the Mk III Grebe, that first flew in February 1925. It differed from the Grebe primarily by way of its Bristol Jupiter engine, which replaced the unreliable Armstrong Siddeley Jaguar. Other changes included improved ailerons, refined fuselage contours, and internally mounted machine guns. The Gamecock had a fairly short RAF service life, partly because of its high accident rate - of the 90 operated by the RAF, 22 were lost in landing or spin accidents. These faults were remedied in the Mk. II version, by means of a longer upper wing and a modified tail unit. Gamecock Mk I : Single-seat fighter aircraft for the RAF. 90 built. Gamecock Mk II : Single-seat fighter aircraft with revised wing and tail. One new built for RAF with another Mk I converted to Mk II standard. Three were three exported to Finland in 1928, with a further 15 built under licence in Finland from 1929- 1930 as the Kukko. Gamecock Mk III : One RAF Gamecock Mk II modified with lengthened fuselage for spin trials.