The Martin 4-0-4 (also written as 404) is an American twin-engined piston airliner developed by the Glenn L. Martin Company.
The Martin 2-0-2 was envisaged as a replacement for the Douglas DC-3, but its lack of pressurization meant it could not compete with the Convair 240. The 2-0-2 was thus modified into the Martin 3-0-3, which was then given new wings due to structural problems in the original wings. The new aircraft was given the designation 4-0-4, and made its first flight on 21 October 1950.
The deliveries began in 1951 with Eastern Air Lines receiving 60 and Trans World Airlines 40. Two were ordered by the United States Coast Guard and used as executive transports. Despite the added pressurization, the 4-0-4 lost to the Convair 240 and no more 4-0-4s were sold. The Coast Guard 4-0-4s were given to the Navy in 1969, but retired soon after.
The old Martin 4-0-4s of Eastern and TWA later served with several smaller airlines until mid-1980s. They were among the last piston-engined airliners to be operated in commercial service in the United States. The last flight of the type was a ferry flight to a museum in 2008.
Eight intact 4-0-4s survive, along with a fuselage and a cockpit.
- 4-0-4 - The airliner version. 101 built.
- RM-1G - Executive transport of the United States Coast Guard. Two built. Later redesignated as RM-1 and finally VC-3A in 1962.
- Crew: 3 or 4
- Capacity: 40 passengers
- Length: 74 ft 7 in (22.73 m)
- Wingspan: 93 ft 3 in (28.42 m)
- Height: 28 ft 5 in (8.66 m)
- Wing area: 864 sq ft (80.3 m2)
- Airfoil: GLM-W 16
- Empty weight: 29,126 lb (13,211 kg)
- Max takeoff weight: 44,900 lb (20,366 kg)
- Powerplant: 2 × Pratt & Whitney R-2800-CB16 18-cylinder two-row air-cooled radial engine, 2,400 hp (1,800 kW) each (take off power), 1,800 hp (1,300 kW) (normal power)
- Propellers: 3-bladed Hamilton Standard 2H17K3-48R, 13 ft 2 in (4.01 m) diameter
- Maximum speed: 312 mph (502 km/h, 271 kn) at 14,500 ft (4,400 m)
- Cruise speed: 280 mph (450 km/h, 240 kn) at 18,000 ft (5,500 m)
- Stall speed: 81 mph (130 km/h, 70 kn) at sea level
- Range: 1,080 mi (1,740 km, 940 nmi)
- Ferry range: 2,600 mi (4,200 km, 2,300 nmi)
- Service ceiling: 29,000 ft (8,800 m)
- Rate of climb: 1,905 ft/min (9.68 m/s)
- Take-off distance to 50 ft (15 m): 1,980 ft (600 m)
- Landing distance from 50 ft (15 m): 1,750 ft (530 m)