Modern-Aviation

The most famous, as well as the most important, British flying boat of the war was undoubtedly the Short S-25 Sunderland, which first flew in 1937. This four-engine RAF reconnaissance and maritime patrol flying boat was essentially the military version of the Short Empire civil transport. It was the first flying boat to be equipped with power operated gun turrets and was produced in four successive variations, the Mk. I, II, III and V. (The Mk. IV Sunderland was developed into the improved Seaford flying boat.) Typical defensive armament of the Sunderland V was 8-.303 machine guns arranged in a twin turret in the nose, a dorsal twin turret and a quad tail turret. Provision was made for the installation of four fixed .303 machine guns in the nose and two beam .303 machine guns. Disposable ordinance included bombs, depth charges and mines. There was a bombardier's position in the nose. The Mk. V's performance was improved over previous models by substituting 1200 hp Pratt & Whitney Twin Wasp radial engines with improved propellers for the underpowered Pegasus engines. This was a very satisfactory change, for while performance was increased, range and endurance remained about the same.

Sunderlands were fitted with airborne surface search radar early on, starting with the Mk. I. Their radar was continually upgraded as the war went on and later models had increasingly sophisticated installations that made them very effective submarine hunters.

749 Sunderlands were completed before production ceased in 1946. Sunderlands served in the RAF in the Far East until 1959 and with the Royal New Zealand Air Force until 1967. The type also served with the Australian Air Force, Canadian Air Force, South African Air Force, Norwegian Air Force, Portuguese Navy and the French Navy. After the war, converted Sunderland flying boats were operated by a number of civilian air lines. Following are some specifications for the Sunderland III, the most numerous model with some 467 completed.

General characteristics
Crew: 9–11 (two pilots, radio operator, navigator, engineer, bomb-aimer, three to five gunners)
Length: 85 ft 4 in (26.0 m)
Wingspan: 112 ft 9½ in (34.39 m)
Height: 32 ft 10½ in (10 m)
Wing area: 1,487 ft² (138 m²)
Empty weight: 34,500 lb (15,663 kg)
Loaded weight: 58,000 lb (26,332 kg)
Powerplant: 4 × Bristol Pegasus XVIII nine-cylinder radial engine, 1,065 hp (794 kW) each

Performance
Maximum speed: 210 mph (336 km/h) at 6,500 ft (2,000 m)
Cruise speed: 178 mph (285 km/h) at 5,000 ft (1,500 m)
Stall speed: 78 mph (125 km/h)
Range: 1,780 mi (2,848 km)
Service ceiling: 16,000 ft (4,880 m)
Rate of climb: 720 ft/min (3.67 m/s)
Wing loading: 39 lb/ft² (191 kg/m²)
Power/mass: .073 hp/lb (.121 kW/kg)

Armament
Guns:
16× 0.303 inch (7.7 mm) Browning machine guns
2× Browning 0.5 inch (12.7 mm) machine gun
Bombs: various defensive and offensive munitions, including bombs, mines and depth charges carried internally and, some, winched out beneath the wings. Manually launched flares, sea markers and smoke-floats.

Role: Military flying boat bomber
Manufacturer: Short Brothers
Designer: Arthur Gouge
First flight: 16 October 1937
Introduction: 1938
Retired: RAF: 1959
               RNZAF: 1967
Status: Retired
Primary users: Royal Air Force
                          French Navy
                          Royal Australian Air Force
                          Royal New Zealand Air Force
Produced: 1938–1946
Number built: 749
Variants: Short Sandringham
                Short Seaford