 Testing commenced in August 1937 and revealed a number of serious deficiencies in the design, including that the aircraft was overweight and impossible to control directionally when flying on only one engine as the ailerons caused severe drag tending to turn the aircraft in the opposite direction.The RCAF tested the 45-80 in October 1937, investigating its potential as a photographic platform, but ultimately rejecting it.Canadian Airways tests showed that the new design had a payload capacity no greater than the single-engine types that they were already operating.