Closely related to Northrop's Gamma mail plane, 13 were produced by the Northrop Corporation, followed by 19 aircraft built under license by Canadian Vickers Limited.
Terkait erat dengan pesawat surat Northrop Gamma, 13 di antaranya dihasilkan oleh Northrop Corporation, diikuti oleh 19 pesawat dibangun di bawah lisensi oleh Canadian Vickers Limited.