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Westland Welkin Twin-Engine High-Altitude Interceptor / Heavy Fighter

The Westland Welkin was a promising twin-engine, high-altitude interceptor designed in anticipation of another Luftwaffe bombing campaign over Britain.

 Updated: 7/12/2017; Authored By Staff Writer; Content ¬©

With its origins in the Westland Whirlwind, the Westland Welkin (meaning "Vault of Heaven") was a twin-engined fighter designed as a high-altitude interceptor to defend against another possible Luftwaffe bombing campaign against the English mainland. The appearance of Germany's modified Junkers Ju 86 reconnaissance bombers brought about the memories of the Battle of Britain Luftwaffe bombing raids that were an all-too-common occurrence throughout the summer of 1940. The Welkin was eventually developed and produced but led on non-descript operational existence for the Royal Air Force as the new Luftwaffe bombing campaign over England never materialized. As such, the Welkin was deemed unnecessary and modified high-altitude Supermarine Spitfires were more than capable of achieving the same result.

Designed by W.E.W. Petter, the Welkin was first flown on November 1st, 1942 as a development to fulfill Specification F.4/40 requiring a new high-altitude fighter for the Royal Air Force. The Welkin fitted a single pilot in the extreme forward portion of a streamlined central fuselage. The pilot was afforded good views from his raised position. Engines were fitted to nacelles under each high-mounted monoplane wing. Wings were a distinctive characteristic of the Welkin, formed as long-span, high-aspect ratio assemblies emanating from the forward fuselage. Powerplants were of Rolls-Royce-brand Merlin 76 series, liquid-cooled, inline piston engines delivering up to 1,233 horsepower each. The empennage consisted of a conventional "T-style" arrangement. Armament centered on nose-mounted 4 x 20mm Hispano cannons fitted to an underside-fuselage tray for ease-of-maintenance, repair and reloading while protecting the pilot from the flashing of his cannons if fired in the dark.

Performance specifications for the Welkin were impressive, allowing for top speeds of up to 330 miles-per-hour. The Welkin was one of the first Royal Air Force aircraft design attempts to feature a pressurized cockpit, allowing the aircraft to reach altitudes upwards of 44,000 feet but at the same time requiring the use of a high-altitude suit and the wearing of an oxygen mask. The long span wings were essential in providing for stabilized high-altitude flying.

The Welkin was introduced into active service in May of 1944 as the F.Mk I with Royal Air Force's Fighter Interception Group at Wittering. Two prototype night-fighters also appeared under the designation of NF.Mk IIA based on Specification F.9/43 and were to be of a twin-seat derivative based on the single-seat interceptor model but instead outfitted for night-interception sorties. The night-fighter form never materialized into production examples.

Total production of the base Welkin F.Mk I interceptor totaled 75 examples along with 26 other airframes (sans engines) completed.

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Westland Welkin F.Mk I Technical Specifications

Service Year: 1944
Type: Twin-Engine High-Altitude Interceptor / Heavy Fighter
National Origin: United Kingdom
Manufacturer(s): Westland - UK
Production Total: 75

Structural (Crew Space, Dimensions and Weights)

Operating Crew (Typical): 1
Overall Length: 41.57 feet (12.67 meters)
Overall Width: 69.88 feet (21.30 meters)
Overall Height: 15.75 feet (4.80 meters)

Weight (Empty): 8,307 lb (3,768 kg)
Weight (MTOW): 11,409 lb (5,175 kg)

Installed Power and Standard Day Performance

Propulsion: 2 x Rolls-Royce Merlin 76 liquid-cooled inline piston engines developing 1,233 horsepower each.

Maximum Speed: 388 mph (625 kph; 337 knots)
Maximum Range: 1,200 miles (1,931 km)
Service Ceiling: 44,029 feet (13,420 meters; 8.34 miles)

Armament / Mission Payload

4 x 20mm Hispano cannons in nose

Global Operators / Customers

United Kingdom

Model Variants (Including Prototypes)

Welkin F.Mk I - Base Production Designation
Welkin NF.Mk II - Two -Seat Night-fighter Prototype tested in 1945.