Douglas M-1 / M-2 / M-3 / M-4 (Mailplane)
Mail Aircraft
The Douglas M-1 / M-2 / M-3 / M-4 is a series of single-engine single-seat mailplanes produced by the US-American manufacturer Douglas Aircraft Company. The M-2 was the first production model.
The Douglas M-series is a development of the Douglas O-2 observation aircraft.
| Crew | 1 | |
| Propulsion | 1 Piston Engine | |
| Engine Model | Liberty L-12 | |
| Engine Power | 298 kW | 400 hp |
| max. Cruise Speed | 178 km/h | 96 kts 110 mph |
| max. Speed (vne) | 224 km/h | 121 kts 139 mph |
| Service Ceiling | 5.029 m | 16.500 ft |
| Range | 1.128 km | 609 NM 701 mi. |
| Empty Weight | 1.542 kg | 3.400 lbs |
| max. Takeoff Weight | 2.223 kg | 4.900 lbs |
| Wing Span | 13,56 m | 44 ft 6 in |
| Wing Area | 38,2 m² | 411 ft² |
| Length | 8,81 m | 28 ft 11 in |
| Height | 3,07 m | 10 ft 1 in |
| First Flight | 1925 | |
| Production Status | out of production | |
| Total Production | 57 | |
| Developed from | Douglas O-2 | |
| Data for (Version) | Douglas M-4 | |
| Variants | Douglas M-1, M-2, M-3, M-4 | |
| [Photo-ID: 10265] © Karsten Palt 2014-05-28 | |
![]() | Douglas M-4 Mailplane Western Air Express Reg.: NC1475 c/n: 338 last existing Douglas Mailplane, displayed as Douglas M-2, NC150, c/n 244 |
| NASM Udvar Hazy Center [Chantilly, VA] | |
| [Photo-ID: 10266] © Karsten Palt 2014-05-28 | |
![]() | Douglas M-4 Mailplane Western Air Express Reg.: NC1475 c/n: 338 last existing Douglas Mailplane, displayed as Douglas M-2, NC150, c/n 244 |
| NASM Udvar Hazy Center [Chantilly, VA] | |



