 By this point the Air Ministry was desperate to get any unit into service . Satisfied with his visit in May , Dowding suggested that the Mk . I was good enough for operational testing purposes . On 11 June 1939 , AI was given the highest priority and provisions were made to supply 11 additional Blenheims to No 25 squadron at RAF Hawkinge ( for a total of 21 ) . Since each of the parts came from different suppliers , and the fitters were unfamiliar with any of it , members of the AI team would have to hand @-@ assemble the components as they arrived and instruct the fitters on the sets . 
