 Completion of the trials would be delayed until May 1947 when the trials of the VRDK itself would be completed and Mikoyan tried to sell the aircraft to Naval Aviation for use as escorts for torpedo bombers . Additional fuel tanks were fitted in the wings and fuselage of 3810102 to carry an additional 218 litres ( 48 imp gal ; 58 US gal ) of fuel and the capacity of the oil tank was increased to 78 litres ( 17 imp gal ; 21 US gal ) . These changes increased its empty weight to 3 @,@ 028 kg ( 6 @,@ 676 lb ) and its take @-@ off weight to 3 @,@ 931 kg ( 8 @,@ 666 lb ) . A new round of State trials began on 9 October 1947 , but these were delayed by bad weather and reliability issues . Only six flights totaling two hours and twenty @-@ five minutes had been completed by 21 January 1948 and the VRDK had only been run for a minute and half during a ground test . The I @-@ 250 was unsurprisingly declared to have failed the trials on 3 April 1948 . 
