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Armstrong Whitworth AW681

United Kingdom (1965)
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Origin: United Kingdom
Year: 1965
Type: Four-Engined STOL Transport Aircraft
Manufacturer(s): Armstrong Whitworth / Hawker Siddeley / Whitworth Gloster - UK
Production: 0
Status: Cancelled

The Armstrong Whitworth AW681 briefly challenged as an STOL military transport product but the project was cancelled in February of 1965.

Detailing the development and operational history of the Armstrong Whitworth AW681 Four-Engined STOL Transport Aircraft.  Entry last updated on 1/12/2018. Authored by Staff Writer. Content ©

Like the United States Air Force (USAF) during the 1960s, the British Royal Air Force (RAF) also sought a tactically-minded Short Take-Off and Landing (STOL) aircraft of strong performance to replace a mixed and aging fleet of transports made up of Blackburn Beverly and Handley Page Hasting aircraft. Between two submissions, one from Hawker Siddeley and the other from Armstrong Whitworth (AW), the AW design was selected for development as the "AW.681" to fulfill "Operational Requirement 351". The project formally began in 1962 (under the designation of Hawker Siddeley "HS.681") with the goal of seeing a first-flight recorded sometime in 1966.

AW engineers selected a conventional arrangement for their new aircraft, incorporating swept-back wing mainplanes and a "T-style" tail unit. The empennage would be raised to accommodate a loading ramp under the tail and the flightdeck would be sat over the nose in the usual way. Two engine nacelles (with a deflected-thrust capability) would be held under each wing. The engine of choice became the Rolls-Royce RB.142 "Medway" of 13,790lb thrust each with the alternative being the Bristol Siddeley "Pegasus" ducted-flow turbofan (18,000lb thrust each) coupled with 18 x RB.162-64 "lifting fans" (6,000lb thrust output) installed to cover a Vertical Take-Off and Landing (VTOL) capability. A tricycle undercarriage would allow for ground-running. Blown flaps would aid in low-altitude control and short-field take-off and landing actions. Internally, the aircraft could carry around 35,000lb of cargo or sixty combat-ready troops.

Dimensions included a length of 104.1 feet, a wingspan of 134 feet and a height of 37.9 feet. Maximum Take-Off Weight (MTOW) would reach 181,200lb. Maximum speed was estimated at 545 miles per hour with a range out to 4,800 miles and a service ceiling of 25,000 feet.
Just as soon as the AW.681 project was to get "off the ground", it was cancelled by the incoming government (Labour Party) in February of 1965 after review of ongoing military programs. The RAF then decided to secure a fleet of Lockheed C-130 "Hercules" aircraft for the transport role instead and this marked the official end of the AW.681 tale. The aircraft existed for a short time beyond that when Armstrong-Whitworth attempted to sell the same aircraft (sans the complicated VTOL capability) by combining the existing designs of the AW.681 fuselage and tail with the wings and engines of the Hawker Siddeley "Nimrod". This idea did not progress.

The AW.681 product was also known as the Whitworth Gloster Model 681.

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.

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Relative Maximum Speed Rating
Hi: 750mph
Lo: 375mph
    This entry's maximum listed speed (544mph).

    Graph average of 562.5 miles-per-hour.
City-to-City Ranges
Graph showcases the Armstrong Whitworth AW681's operational range (on internal fuel) when compared to distances between major cities.
Aviation Era
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Unit Production Comparison
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
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Global Operators:
United Kingdom (cancelled)
Historical 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 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 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
* Ribbons not necessarily indicative of actual historical campaign ribbons. Ribbons are clickable to their respective campaigns/operations.
Measurements and Weights icon
Structural - Crew, Dimensions, and Weights:
Unless otherwise noted the presented statistics below pertain to the Armstrong Whitworth AW681 model. Common measurements, and their respective conversions, are shown when possible.




104.17 ft

31.75 m


134.02 ft

40.85 m


37.89 ft

11.55 m


181,573 lb

82,360 kg

Engine icon
Installed Power - Standard Day Performance:
4 x Rolls-Royce Medway turbofan engines (with thrust deflection) developing 13,800lb of thrust each.


544 mph

875 kph

472 kts


4,800 mi

7,725 km

Nautical Miles
4,171 nm


25,000 ft

7,620 m

4.73 mi

Armament - Hardpoints (0):

Variants: Series Model Variants
• AW.681 - Base Project Designation
• HS.681 - Alternative designation under the Hawker Siddeley brand label.
• Model 681 - Alternative designation under Whitworth Gloster brand label.