Blackburn Kangaroo The Blackburn R . T . 1 Kangaroo was a British twin - engine reconnaissance torpedo biplane of the First World War , built by Blackburn Aircraft . World War I . In 1916 , the Blackburn Aircraft Company designed and built two prototypes of an anti - submarine floatplane designated the Blackburn G . P . or Blackburn General Purpose . It was not ordered but Blackburn developed a landplane version as the Blackburn R . T . 1 Kangaroo ( Reconnaissance Torpedo Type 1 ) . The first aircraft was delivered to Martlesham Heath in January 1918 . Test results were disappointing , with the rear fuselage being prone to twisting and the aircraft suffering control problems , which lead to the existing order for 50 aircraft being cut back to 20 , most of which were already part built . From the sixth aircraft onwards , they were powered by the more powerful Rolls - Royce Falcon III engine replacing the 250 hp ( 120 kW ) Rolls - Royce Falcon II . The Kangaroo entered service later that year with No . 246 Squadron RAF based at Seaton Carew , County Durham which had six months of wartime operations and they sank one U - Boat , " UC - 70 " , which was spotted lying submerged on the sea bottom near Runswick Bay on 28 August 1918 by a Kangaroo flown by Lt E . F . Waring , the U - boat being badly damaged by a near miss by a 520 lb ( 240 kg ) bomb and finished off by the destroyer HMS " Ouse " , and damaged four others . Post - World War I . In 1919 , three surviving RAF Kangaroos were sold to the Grahame - White Aviation Co Ltd based at Hendon Aerodrome . Eight others were sold back to Blackburn Aircraft , three being converted with a glazed cabin for its subsidiary , North Sea Aerial Navigation Co Ltd , also based at Brough Aerodrome . Several different configurations were embodied for the civil market , for cargo , pilot training and / or the accommodation of up to eight passengers . In the first few months of 1919 , most of these converted aircraft continued to fly ( and sometimes crash ) in military markings , then the survivors were repainted with civilian registrations and commercial titles . In May 1919 , joy - riding , cargo and passenger charters took place at locations including Brough , Leeds , West Hartlepool , Gosport , Hounslow Heath . During August 1919 , three Kangaroos flew to Amsterdam for the ELTA air traffic exhibition , and spent several weeks giving flights to an estimated 1 , 400 passengers . On 30 September 1919 , North Sea Aerial Navigation Co Ltd started a regular passenger service between Roundhay Park ( Leeds ) and Hounslow Heath . In 1920 , the company was renamed North Sea Aerial & General Transport Co Ltd , and services were extended to Amsterdam . On 21 November 1919 , one Kangaroo ( G - EAOW ) took off from Hounslow Heath in an attempt to win the Australian government prize of £A10 , 000 for the first Australian airman to fly a British aircraft from the UK to Australia within 30 consecutive days . The Kangaroo was forced to make an emergency landing at Suda Bay , Crete with a suspected sabotaged engine , and the aircraft was abandoned there . On 8 September 1922 , two Kangaroos took part in the King ' s Cup Air Race from Croydon Aerodrome , but both retired . In 1924 , under contract with the North Sea Aerial & General Transport Co Ltd , the RAF used three Kangaroos ( named Pip , Squeak and Wilfred after popular cartoon characters ) as dual - control trainers for refresher training , but by 1929 the last Kangaroo had been withdrawn from service , and scrapped .