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Westland Welkin

Twin-Engine High-Altitude Interceptor / Heavy Fighter

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.
National Flag Graphic
ORIGIN: United Kingdom
YEAR: 1944
STATUS: Retired, Out-of-Service
OPERATORS: United Kingdom

Unless otherwise noted the presented statistics below pertain to the Westland Welkin F.Mk I model. Common measurements, and their respective conversions, are shown when possible.
LENGTH: 41.57 feet (12.67 meters)
WIDTH: 69.88 feet (21.3 meters)
HEIGHT: 15.75 feet (4.8 meters)
WEIGHT (EMPTY): 8,307 pounds (3,768 kilograms)
WEIGHT (MTOW): 11,409 pounds (5,175 kilograms)
ENGINE: 2 x Rolls-Royce Merlin 76 liquid-cooled inline piston engines developing 1,233 horsepower each.
SPEED (MAX): 388 miles-per-hour (625 kilometers-per-hour; 337 knots)
RANGE: 1,200 miles (1,931 kilometers; 1,043 nautical miles)
CEILING: 44,029 feet (13,420 meters; 8.34 miles)

4 x 20mm Hispano cannons in nose
Graphical image of an aircrat automatic cannon

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


Detailing the development and operational history of the Westland Welkin Twin-Engine High-Altitude Interceptor / Heavy Fighter.  Entry last updated on 1/21/2019. 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.


Our Data Modules allow for quick visual reference when comparing a single entry against contemporary designs. Areas covered include general ratings, speed assessments, and relative ranges based on distances between major cities.

Image of collection of graph types

Relative Maximum Speed
Hi: 400mph
Lo: 200mph
This entry's maximum listed speed (388mph).

Graph average of 300 miles-per-hour.
City-to-City Ranges
Graph showcases the Westland Welkin F.Mk I's operational range (on internal fuel) when compared to distances between major cities.
Aviation Era
Pie graph section
Pie graph section
Pie graph section
Pie graph section
Pie graph section
Useful in showcasing the era cross-over of particular aircraft/aerospace designs.
Unit Production (75)
Comm. Market HI*: 44,000 units
Military Market HI**: 36,183 units

  * Commercial Market High belongs to Cessna 172.

  ** Military Market High belongs to Ilyushin Il-2.

Altitude Visualization
Small airplane graphic
Supported Roles
Ground Attack
Aerial Tanker
A2A=Air-to-Air; UAV=Unmanned; CAS=Close Support; ASW=Anti-Submarine; AEW=Airborne Early Warning; MEDEVAC=Medical Evac; EW=Electronic Warfare; SAR=Search-Rescue
Commitments / Honors
Military lapel ribbon for Operation Allied Force
Military lapel ribbon for the Arab-Israeli War
Military lapel ribbon for the Battle of Britain
Military lapel ribbon for the Battle of Midway
Military lapel ribbon for the Berlin Airlift
Military lapel ribbon for the Chaco War
Military lapel ribbon for the Cold War
Military lapel ribbon for the Cuban Missile Crisis
Military lapel ribbon for pioneering aircraft
Military lapel ribbon for the Falklands War
Military lapel ribbon for the French-Indochina War
Military lapel ribbon for the Golden Age of Flight
Military lapel ribbon for the 1991 Gulf War
Military lapel ribbon for the Indo-Pak Wars
Military lapel ribbon for the Iran-Iraq War
Military lapel ribbon for the Korean War
Military lapel ribbon for the 1982 Lebanon War
Military lapel ribbon for the Malayan Emergency
Military lapel ribbon representing modern aircraft
Military lapel ribbon for the attack on Pearl Harbor
Military lapel ribbon for the Six Day War
Military lapel ribbon for the Soviet-Afghan War
Military lapel ribbon for the Spanish Civil War
Military lapel ribbon for the Suez Crisis
Military lapel ribbon for the Vietnam War
Military lapel ribbon for Warsaw Pact of the Cold War-era
Military lapel ribbon for the WASP (WW2)
Military lapel ribbon for the World War 1
Military lapel ribbon for the World War 2
Military lapel ribbon for the Yom Kippur War
Military lapel ribbon for experimental x-plane aircraft
* Ribbons not necessarily indicative of actual historical campaign ribbons. Ribbons are clickable to their respective campaigns/operations.

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