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Avro 531 Spider

Single-Seat Biplane Fighter Prototype

Avro 531 Spider

Single-Seat Biplane Fighter Prototype

OVERVIEW
SPECIFICATIONS
ARMAMENT
VARIANTS
HISTORY
MEDIA
OVERVIEW



The Avro 531 Spider failed to overtake the venerable Sopwith Camel in terms of performance - leaving just two prototypes completed.
National Flag Graphic
ORIGIN: United Kingdom
YEAR: 1918
STATUS: Cancelled
MANUFACTURER(S): A.V.Roe (Avro) - United Kingdom
PRODUCTION: 2
OPERATORS: United Kingdom (cancelled)
SPECIFICATIONS



Unless otherwise noted the presented statistics below pertain to the Avro 531 Spider model. Common measurements, and their respective conversions, are shown when possible.
CREW: 1
LENGTH: 20.51 feet (6.25 meters)
WIDTH: 28.54 feet (8.7 meters)
HEIGHT: 7.87 feet (2.4 meters)
WEIGHT (EMPTY): 970 pounds (440 kilograms)
WEIGHT (MTOW): 1,543 pounds (700 kilograms)
ENGINE: 1 x Clerget (Gwynnes) 9B air-cooled rotary piston engine developing 130 horsepower and driving a two-bladed wooden propeller at the nose.
SPEED (MAX): 121 miles-per-hour (195 kilometers-per-hour; 105 knots)
RANGE: 249 miles (400 kilometers; 216 nautical miles)
CEILING: 19,685 feet (6,000 meters; 3.73 miles)
RATE-OF-CLIMB: 1,250 feet-per-minute (381 meters-per-minute)




ARMAMENT



PROPOSED:
1 x 7.7mm Vickers machine gun over the nose synchronized to fire through the spinning propeller blades.
VARIANTS



Series Model Variants
• Model 531 "Spider" - Base Series Name; two prototypes completed.
• Model 531A - Proposed refined variant; left incomplete.
• Model 538 - Proposed racer form built upon the Model 531 framework.


HISTORY



Detailing the development and operational history of the Avro 531 Spider Single-Seat Biplane Fighter Prototype.  Entry last updated on 8/21/2018. Authored by Staff Writer. Content ©www.MilitaryFactory.com.
The Avro 531 "Spider" began life as a private venture attempt by the company to provide an all-modern biplane fighter for British service during the latter stages of World War 1 (1914-1918). Its design was attributed to Roy Chadwick and was influenced heavily by work related to the company's earlier Type 504 biplane (detailed elsewhere on this site). With a first-flight held during April of 1918, the Avro 531 was not adopted for service as British authorities committed to the competing Sopwith Snipe (detailed elsewhere on this site) going forward. This left just two Spider prototypes completed.

In the Model 531 design, the traditional biplane arrangement of the period was featured. However, the upper wing section was held close to the dorsal surface of the fuselage thus affording the pilot with better vision over and around his aircraft. Additionally, the lower wing section was of much smaller surface area than the larger (sesquiplane). V-type (Warren truss-style) interplane struts were used for bracing the wing members to one another and this gave the appearance of a spider's web when viewing the aircraft from the front profile - hence the aircraft's name of "Spider". The engine was held in a forward compartment and the tail unit was wholly traditional. The undercarriage was fixed and of a tail-dragger arrangement. Seating was for one in an open-air cockpit and proposed armament being 1 x 7.7mm Vickers machine gun sat over the nose and synchronized to fire through the spinning propeller blades.

Power was from a French-originated, British-produced (by Gwynnes Ltd) Clerget 9B air-cooled rotary piston engine of 130 horsepower output driving a two-bladed propeller at the nose. Maximum speed became 120 miles per hour with an operational range out to 250 miles and a service ceiling of 19,000 feet. Rate-of-climb was listed at 1,250 feet per minute.

All told, the Spider exhibited excellent control and was highly agile in addition to providing better situational awareness for the pilot when compared to contemporaries. However, in the opinion of the War Office, it did not best the overall performance of the competing in-service Sopwith Camel fighter and the Air Service moved on the Sopwith Snipe instead.

The Model 531A (with revised strutworks) was also in development at the time and was to appear as a refined version of the original. It appears that this variant was not finished and went on to influence the related high-speed Model 538 racer. This design, too, failed to see completion and the whole airframe was scrapped by 1920.




MEDIA









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 Rating
Hi: 150mph
Lo: 75mph
    This entry's maximum listed speed (121mph).

    Graph average of 112.5 miles-per-hour.
City-to-City Ranges
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  LDN
LDN
 
  PAR
PAR
 
  BER
BER
 
  MSK
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  TKY
TKY
 
  SYD
SYD
 
  LAX
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  NYC
Graph showcases the Avro 531 Spider's operational range (on internal fuel) when compared to distances between major cities.
Aviation Era
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Useful in showcasing the era cross-over of particular aircraft/aerospace designs.
Unit Production Comparison
Comm. Market HI*: 44,000 units
Military Market HI**: 36,183 units
2
2

  * Commercial Market High belongs to Cessna 172.

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


Altitude Visualization
Small airplane graphic
Supported Roles
A2A
Interception
UAV
Ground Attack
CAS
Training
ASW
Anti-Ship
AEW
MEDEVAC
EW
Maritime/Navy
SAR
Aerial Tanker
Utility/Transport
VIP
Passenger
Business
Recon
SPECOPS
X-Plane/Development
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