Inside Out Library · ExploreThe Avro 627 "Mailplane" (English): A Single-Seat Biplane (1931)NASA Technical Reports Server (NTRS) · leaf 9Aircraft Circular lTo.150 Fip. 1 5 301 10" mNASA Technical Reports Server (NTRS)Internet Archive · NASA Technical Reports · Public domain (US government work). Free to use for anything.More pictures from The Avro 627 "Mailplane" (English): A Single-Seat BiplaneMore like this