The final version of the Sunderland to enter service was the Mk V, which remained in use in the RAF from early in 1945 until 1959. Early in 1944 Shorts experimented with the use of Pratt & Whitney Twin Wasp engines on a Sunderland III. These engines provided 150 more horsepower each than the Pegasus XVIII used on the Sunderland II and III, and gave the aircraft spare power for the first time.
This had two big advantages. The Pegasus engines of the Sunderland III had to operate at war settings (close to maximum power) most of time, significantly reducing their lifespan. In contrast the Twin Wasps of the Mk V could run at lower power in normal operation, making them much more reliable. The Sunderland V was also the first version of the aircraft that could safely fly even if two engines failed on the same time.
The Sunderland V was equipped with 9cm ASV Mk. VIC radar, as used in the last batch of Mk IIIs. This radar set used split scanners installed in radomes on the wing tips instead of the array of aerials of earlier types of radar.
The Sunderland V went into production late in 1944, and entered service with Nos.228 and 461 Squadrons at Pembroke Dock in February 1945. A total of 153 were produced – 53 by Short and Harland in Belfast and 100 by Blackburn at Dumbarton. Another 88 existing Mk IIIs were given the Pratt & Whitney engines to bring them up to Mk V standard.
It would be the Mk V that remained in RAF service to the end of the 1950s, taking part in the Berlin air lift, patrolling the Yellow Sea during the Korean War and helping to support the British North Greenland expedition.
Engine: Four Pratt & Whitney R-1830-90 Twin Wasp 14 cylinder air-cooled radial
Power: 1,200hp each
Span: 112ft 9in
Length: 85ft 3in
Height: 34ft 6in
Max Speed: 213mph at 5,000ft
Loaded Weight: 60,000lb
Armament: Four fixed forward firing 0.303in machine guns, two 0.303in guns in dorsal turret, four 0.303in guns each in front and tail turret and two (later four) 0.5in guns in beam positions
Bomb load: 2,000lb on retractable racks