[1] Boulton & Paul designed and constructed the prototype P.64 Mailplane to address these requirements.

It was powered by two Bristol Pegasus IM2 supercharged radial engines rated at 555 horsepower (414 kW) driving two-bladed fixed pitch propellers and mounted under the upper wings.

It was destroyed during trials at Martlesham Heath when it struck the ground during an unexplained dive on 21 October 1933.

The company then addressed the specification's requirements with a new design transport aircraft which was lighter, slimmer and longer (the Boulton Paul P.71A).

Data from Boulton Paul Aircraft since 1915[3]General characteristics Performance