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Armstrong Whitworth F.K.9

United Kingdom (1916)
Picture of Armstrong Whitworth F.K.9 Quadruplane Reconnaissance Fighter Prototype

The Armstrong Whitworth F.K.9 successfully sold the Royal Flying Corps on the idea of a quadruplane fighter - this was realized in the F.K.10 series.


Detailing the development and operational history of the Armstrong Whitworth F.K.9 Quadruplane Reconnaissance Fighter Prototype.  Entry last updated on 1/12/2018. Authored by Staff Writer. Content ©www.MilitaryFactory.com

There proved plenty of experimentation with multi-winged aircraft designs during World War 1 (1914-1918). The biplane was more or less the standardized fighter/bomber form while some monoplane fighters did go on to see considerable time in the air. Triplanes managed a short, though useful, revolution but quickly fell out of favor. Beyond these categories was the "quadruplane" - four-winged arrangement intended to harness the agility and control offered from use of four parallel planes in the wing structure, this providing for exceptional lifting and turning properties, qualities critical to close-in dogfights. Several firms of the period experimented with such types but many fell by the wayside as being much too impractical for military service.

Armstrong Whitworth of Britain tried its hand at a quadruplane in the form of the FK.9. It was a two-seat, single-engine form intended for reconnaissance and fighter duties. Development was through private venture in the hopes of interesting the Royal Flying Corps on the design. Its offshoot, the FK.10, would become one of the few quadruplane designs of the war to be adopted form formal service.

First-flight of a prototype FK.9 was had in the summer of 1916 and changes were instituted to remedy several issues: the engine cowling was completely reworked and the tail fin given greater surface area. All-new wings were added and these carried larger-area ailerons as well. The undercarriage track was made wider for improved ground running. Power was served from a Clerget 9Z rotary engine of 110 horsepower driving a simple, two-bladed wooden propeller in the nose. The crew of two sat in tandem across two open-air cockpits, these positioned aft of the four horizontal planes cranked forward. Standard armament was 1 x .303 Vickers machine gun in a fixed, forward-firing emplacement operated by the pilot and 1 x .303 Lewis Gun managed from a trainable mounting by the rear gunner / observer.
The FK.9 was officially evaluated at the Central Flying School during November and into December of 1916. It proved worthy enough to warrant a serial production contract for fifty aircraft - though improvements to the design necessitated the change in designation to "FK.10" for these mounts.

A single FK.9 aircraft was built followed by just 8 x FK.10 - the 50-strong order never fulfilled due to the design's heavy drag. None saw combat service in the whole of the war.






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: 100mph
Lo: 50mph
    This entry's maximum listed speed (84mph).

    Graph average of 75 miles-per-hour.
City-to-City Ranges
NYC
 
  LON
LON
 
  PAR
PAR
 
  BER
BER
 
  MOS
MOS
 
  TOK
TOK
 
  SYD
SYD
 
  LAX
LAX
 
  NYC
Graph showcases the Armstrong Whitworth F.K.9's operational range (on internal fuel) when compared to distances between major cities.
Aviation Era
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Pie graph section
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Unit Production Comparison
Comm. Market HI*: 44,000 units
Military Market HI**: 36,183 units
1
1


  * Commercial Market High belongs to Cessna 172.

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


Altitude Visualization
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National Flag Graphic
Origin: United Kingdom
Year: 1916
Type: Quadruplane Reconnaissance Fighter Prototype
Manufacturer(s): Armstrong Whitworth - United Kingdom
Production: 1
Status: Retired, Out-of-Service
Global Operators:
United Kingdom
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 F.K.9 model. Common measurements, and their respective conversions, are shown when possible.

Operational
CREW


Personnel
2


Dimension
LENGTH


Feet
22.24 ft


Meters
6.78 m


Dimension
WIDTH


Feet
27.89 ft


Meters
8.5 m


Dimension
HEIGHT


Feet
11.48 ft


Meters
3.5 m


Weight
EMPTY


Pounds
1,246 lb


Kilograms
565 kg


Weight
LOADED


Pounds
2,039 lb


Kilograms
925 kg

Engine icon
Installed Power - Standard Day Performance:
1 x Clerget 9Z rotary engine of 110 horsepower driving two-bladed propeller at nose.

Performance
SPEED


Miles-per-Hour
84 mph


Kilometers-per-Hour
135 kph


Knots
73 kts


Performance
RANGE


Miles
211 mi


Kilometers
340 km


Nautical Miles
184 nm


Performance
CEILING


Feet
9,843 ft


Meters
3,000 m


Miles
1.86 mi


Performance
CLIMB RATE


Feet-per-Minute
455 ft/min


Meters-per-Minute
139 m/min

Supported Weapon Systems:

Graphical image of an aircraft medium machine gun
Armament - Hardpoints (0):

1 x .303 Vickers machine gun in fixed, forward-firing position over the nose, synchronized to fire through the spinning propeller blades.
1 x .303 Lewis Gun on trainable mounting in rear cockpit.
Variants: Series Model Variants
• F.K.9 - Base Series Designation; single prototype completed.