Circa 1923.
Awana
Engine: 2 x 450hp Napier Lion
Take-off weight: 8373 kg / 18459 lb
Empty weight: 4536 kg / 10000 lb
Wingspan: 32.16 m / 105 ft 6 in
Length: 20.72 m / 67 ft 12 in
Height: 6.17 m / 20 ft 3 in
Wing area: 213.68 sq.m / 2300.03 sq ft
Max. speed: 156 km/h / 97 mph
Ceiling: 2438 m / 8000 ft
Range: 579 km / 360 miles
Circa 1923.
Engine: 1 x 350hp Jaguar III
Take-off weight: 1855 kg / 4090 lb
Empty weight: 1220 kg / 2690 lb
Wingspan: 12.14 m / 39 ft 10 in
Length: 9.45 m / 31 ft 0 in
Height: 3.96 m / 12 ft 12 in
Wing area: 45.34 sq.m / 488.04 sq ft
Max. speed: 177 km/h / 110 mph
Ceiling: 4618 m / 15150 ft
After the Siddeley Deasy Car Co Ltd acquired in 1921 the name and goodwill of Sir W G Armstrong Whitworth & Co Ltd, which had closed down its aviation department, the Siskin was developed from the Siddeley S.R.2 Siskin, a single-seat fighter of 1919.
The initial Siskin of all-wood construction flew with the Dragonfly engine for the first time in May of 1919. The aircraft itself proved a capable mount though the engine left much to be desired. Retaining the basic features, the Siskin II was redesigned structurally, with fuselage and wing spars of high-tensile steel tubing and strip. The Siskin II appeared in August 1922 as a two-seater powered by a 325hp Armstrong Siddeley Jaguar I 14-cylinder two-row radial. A second prototype followed in October 1923 was a single-seat fighter. The first prototype was later modified as a single-seater. The Siskin II did not attract any orders, and the second prototype was eventually sold to the Swedish Air Force.
The air-cooled radial piston engine was fitted to the extreme forward end of the fuselage sans a cowl and powered a two-blade propeller. The fuselage itself, though all-metal throughout her internal structure, was still covered over in tight fabric and was originally slab-sided and boxy in appearance. This later gave way to a more circular design thanks to an all-new engine installation. As a biplane, the Siskin featured an unequal-span upper and lower straight-wing assembly with slight dihedral. Wings were set in a single bay arrangement and featured V-type struts and were further braced to the fuselage via additional struts located just forward of the cockpit.
The cockpit was set aft from the powerplant and was open. The fuselage was capped aft by a conventional empennage featuring a rounded vertical stabilizer and applicable horizontal planes. The undercarriage was fixed in place and consisted of two main single-wheeled landing gear legs and a simple tail skid at the rear.
Armament was 2 x .303 (7.7mm) Vickers brand machine guns synchronized to fire through the spinning propeller via an interrupter gear. These were fitted to the forward fuselage just ahead of the pilot’s windscreen. An external load of 4 x 20lb bombs was carried externally under the wings (two to a wing).
By this time, the British Air Ministry had made a decision to pursue all-metal fighters for their future needs – the fear being that another war could spell shortages of wood and thusly affect the capability of wood-based fighter production in the UK. As such, the Siskin was redesigned in 1923 to incorporate an all-metal aluminum alloy internal frame.
Embodying considerable redesign, the Siskin III featured an enlarged upper wing, a lower wing of reduced chord and Vee-type interplane struts. The Siskin III was powered by the 350hp Armstrong Siddeley Jaguar III engine, and was ordered for the RAF to Specification 15/22 and flown on May 7th, 1923.
The Royal Air Force (RAF) ordered six for evaluation. Tests were conducted in January of 1924 and proved quite promising to the point that the Siskin III was officially accepted into service with the RAF. The Siskin became the RAFs first all-metal fighter, the first production example flying on 24 March 1924. Armament comprised two 7.7mm Vickers machine guns, and 50 single-seat examples were built for the RAF, one of these later being passed to the RCAF. Twelve two-seat trainer models were also built.
The definitive Siskin became the Siskin IIIA, built to Specification 19/23, of which some 348 were produced with 340 of these slated for the RAF and the remaining 8 for the Royal Canadian Air Force. The IIIA brought about a longer fuselage with raised aft decking, greater gap and less upper wing dihedral, redesigned vertical tail surfaces, and a rounded sided fuselage. Performance specifications included a top speed of 156 miles per hour, a range of 280 miles, a service ceiling of 27,000 feet and a rate-of-climb of 2,953 feet per minute. Endurance 1 x 425hp Armstrong Siddeley Jaguar IV or super-charged Jaguar IVS series radial piston engine provided for a good “bump” to performance above 10,000 feet was listed at roughly 1 hour and 12 minutes. Retaining the twin 7.7mm Vickers gun armament, the Siskin IIIA could reach 10,000 feet in just over 7 minutes (7minutes, 5 seconds).
The Siskin IIIA first flew on 20 October 1925, and was ordered for the RAF in June 1926, 412 being built, including 47 dual-control trainers, 17 of the single-seaters were supplied to the RCAF. Of the total production, Armstrong Whitworth built 159, Blackburn 42, Bristol 85, Gloster 74 and Vickers 52.
The Siskin IIIB was a one-off experimental prototype fitting an improved engine in a Townend ring.
The Siskin IIIDC was a two-seat dual control trainer that was built in 53 examples with deliveries to the RAF, Canada and Estonia. The Siskin IV was a single example civilian racer.
The Siskin V preceded the Siskin IIIA and was essentially a development of the Siskin II. The V retained the shorter span upper wing, broader chord lower wing and parallel struts of the original model, but with redesigned vertical tail surfaces, a forward fuselage with rounded sides, and a 385hp Armstrong Siddeley Jaguar III. Armament was two 7.7mm machine guns.
An order for 70 was received from the Romanian government and production was initiated early in 1925, but in March 1925 one of the Romanian Siskin Vs was destroyed in a crash while being flown in the UK by a Romanian test pilot, and the order was cancelled. At that time at least 10 had been completed, but no deliveries had been made. Two Siskin Vs were subsequently flown with civil registrations. The Siskin IV, the sole example of which was built for the 1925 King’s Cup Race, was similar.
The Siskin in British service was fielded by No. 1, 17, 19, 23, 24, 25, 29, 32, 41, 43, 54, 56 and 111 Squadrons. No. 41 Squadron was the first to receive the type (in their base Siskin III forms) in May of 1924 operating out of Northolt and No. 111 Squadron followed. The Siskin IIIA was accepted into service and served the RAF up until October of 1932, which saw the aircraft replaced by the Bristol Bulldog.
In Canadian service, the Siskin flew with No. 1 Squadron. Canada originally evaluated two Siskin III models and ended up ordering 12 IIAs from 1926 through 1931. The evaluation versions were initially field-tested through two British aircraft on loan in an effort to validate its in-flight operation in a winter environment. Canadian use of the Siskin spanned from 1926 through to 1939. The Siskin was finally replaced by the Hawker Hurricane in 1939.
Siskin II
Take-off weight: 1021 kg / 2251 lb
Wingspan: 8.63 m / 28 ft 4 in
Length: 6.55 m / 21 ft 6 in
Height: 2.89 m / 9 ft 6 in
Wing area: 23.50 sq.m / 252.95 sq ft
Max. speed: 238 km/h / 148 mph
Siskin III
Take-off weight: 1241 kg / 2736 lb
Empty weight: 830 kg / 1830 lb
Wingspan: 10.08 m / 33 ft 1 in
Length: 6.85 m / 22 ft 6 in
Height: 2.97 m / 9 ft 9 in
Wing area: 27.50 sq.m / 296.01 sq ft
Max. speed: 216 km/h / 134 mph
Siskin IIIA
Engine: 1 x Armstrong Siddeley Jaguar IV or IVS, 313/336kW
Wingspan: 10.11 m / 33 ft 2 in
Length: 7.72 m / 25 ft 4 in
Height: 3.10 m / 10 ft 2 in
Wing area: 27.22 sq.m / 292.99 sq ft
Take-off weight: 1366 kg / 3012 lb
Empty weight: 935 kg / 2061 lb
Max. speed: 251 km/h / 156 mph / 136kt
Maximum Range: 280miles (450km)
Rate-of-Climb: 1,538ft/min (469m/min)
Ceiling: 8230 m / 27000 ft
Armament: 2 x 7.7mm Vickers machine-guns, 4 x 20lb / 9kg bombs
Hardpoints: 4
Crew: 1
Siskin V
Take-off weight: 1116 kg / 2460 lb
Wingspan: 8.63 m / 28 ft 4 in
Length: 6.55 m / 21 ft 6 in
Height: 2.89 m / 9 ft 6 in
Wing area: 23.50 sq.m / 252.95 sq ft
Max. speed: 249 km/h / 155 mph
One of three new types of airliner ordered by Imperial Airways on its formation in 1924, the others being the Handley Page W.8f and de Havilland Hercules. First flown on 16 March 1926, the Argosy was the aeroplane that introduced luxury air travel on regular services, except for the pilot, who still sat out in the open up front.
The Argosy had a steel tube fuselage and all steel wing construction and was powered by three 385 hp (later 420 hp) Armstrong Siddeley Jaguars.
Armstrong Whitworth Argosy Article
Three Mk.I machines entered service with Imperial Airways on August 5, 1926, and inaugurated the world’s first named luxury air service the lunchtime Silver Wing from London to Paris in May of the following year. Accommodation was reduced from 20 to 18 Passengers, to make room for a steward and buffet.
The four 28 seat Mk.II Argosies followed in 1929 and were had more powerful (420 h.p.) engines in circular, rather than square, nacelles, and the addition of Handley Page slots and servo tabs on the lower wing trailing edge. These latter made the aileron controls finger light and applied bank automatically in a sideslip or flat turn, which made the pilot’s work very much easier.
On 31 March 1929 Imperial Airways Argosy ‘City of Glasgow left Croydon with the first airmail for India.
Argosies were not withdrawn from service until 1935.
Argosy Mk I
Engines: 3 x Armstrong Siddeley Jaguar, 385hp
Take-off weight: 8165 kg / 18001 lb
Wingspan: 27.64 m / 90 ft 8 in
Length: 20.07 m / 65 ft 10 in
Height: 6.05 m / 19 ft 10 in
Wing area: 175.22 sq.m / 1886.05 sq ft
Max. speed: 177 km/h / 110 mph
Cruise speed: 153 km/h / 95 mph
Range: 531 km / 330 miles
Passengers: 20
Argosy Mk II
Engines: 3 x Armstrong Siddeley Jaguar, 420hp
Span 90 ft.
Length 64 ft 6 in.
Height 19 ft.
Wing area 1,890 sq. ft.
Empty weight 12,090 lb
Loaded weight 19,200 lb
Max. speed 110 m.p.h.
Range 405 miles at 90 mph.
Pax cap: 18-20.
Sir W G Armstrong Whitworth & Co Ltd was a major British manufacturing company of the early years of the 20th century. With headquarters in Elswick, Newcastle upon Tyne, Armstrong Whitworth engaged in the construction of armaments, ships, locomotives, automobiles, and aircraft.
In 1847, engineer William George Armstrong founded the Elswick works at Newcastle, to produce hydraulic machinery, cranes and bridges, soon to be followed by artillery, notably the Armstrong breech-loading gun, which re-equipped the British Army after the Crimean War. In 1882, it merged with the shipbuilding firm of Charles Mitchell to form Armstrong Mitchell & Company and at the time its works extended for over a mile (about 2 km) along the bank of the River Tyne. Armstrong Mitchell merged again with the engineering firm of Joseph Whitworth in 1897. The company expanded into the manufacture of cars and trucks in 1902, and created an “aerial department” in 1913, which became the Armstrong Whitworth Aircraft subsidiary in 1920.
In September 1914 built the unsuccessful F.K.1 single-seater. Later (during the war) the F.K.3 and F.K.8 two-seat observation aircraft were delivered in quantity, as improvements on the Government designed B.E.2c.
Armstrong-Whitworth built in 1914 a gondola for non-rigid naval airship HMA No.2 “Willows IV”. This was followed by gondolas for SS.40-49 airships in 1915, developed from F.K.3 fuselage, with 100 hp Green (probably 20 built as spares required), a gondola for SS.27 (also from an F.K.3 fuselage) but with a Renault engine.
The F.K.15 is described as an airship gondola design for the Beta II, F.K.16 and F.K.17 as an airship gondola design for North Sea airships based on the F.K.3 fuselage.
Experimental First World War types included quadruplanes and Armadillo and Ara biplane single-seat fighters. The Airplane Department closed in late 1919, but a new company, named Armstrong Whitworth, was formed in 1920. Products between the wars were the Siskin single-seat fighter and Atlas army cooperaton aircraft for the RAF, both introducing some steel construction. The Scimitar fighter (1934) was among the world’s fastest with a radial engine, partly due to company’s associations with engine-builder Armstrong Siddeley.
By the end of 1924 Armstrong’s was virtually bankrupt. The bank of England discreetly moved in, and eventually brought pressure to force a merger with Vickers, using the Sun Insurance Company as their front to guarantee the new company, now called Vickers Armstrong. It was a condition of the rescue that the new company would restrict themselves to ship building, heavy engineering, and predominantly armaments.
In 1927, it merged with Vickers Limited to form Vickers-Armstrongs.
Notable airliners were the three-engined Argosy biplane (1926), four-engined Atalanta monoplane (1932), and the much larger Ensign (1938). The company’s most famous product was the Whitley twin-engined bomber of 1936, in which year Hawker Siddeley Group was formed, with Armstrong Whitworth as a member company. In July 1943 the 1,824th Whitley left the assembly line at Baginton, Coventry, the type having achieved several historic “firsts” in RAF service. The Albemarle (600 built) was used as glider-tug and transport, and Avro Lancaster bombers were built in dispersed factories. After the war, from the basic Gloster design, the company developed and produced in quantity Meteor two-seat nightfighters. When this type was well advanced they undertook development of the Hawker Sea Hawk naval fighter. Avro Lincolns, Hawker Hunters, and Gloster Javelins also produced. Experiments made with flying-wing aircraft and prone-pilot position were undertaken. The Apollo turboprop airliner (1949) had no commercial success, though the Argosy twin-boom four-turboprop freighter (1959) gained limited civil and military orders.
Gloster, Armstrong Whitworth and Avro joined Hawker Siddeley Aviation in 1965.
The Armstrong Siddeley Tiger was a British 14-cylinder air-cooled aircraft radial engine developed by Armstrong Siddeley in the 1930s from their Jaguar engine. First run in 1932, the engine was built in a number of different versions but performance and dimensions stayed relatively unchanged. The Tiger VIII was the first British aircraft engine to use a two-speed supercharger.
Applications:
Armstrong Whitworth A.W.19
Armstrong Whitworth AW.23
Armstrong Whitworth A.W.29
Armstrong Whitworth Ensign
Armstrong Whitworth Whitley
Blackburn B-6
Blackburn B-7
Blackburn Shark
Blackburn Ripon
Fairey G4/31
Handley Page H.P.51
Short Calcutta
Specifications:
Tiger VIII
Type: 14-cylinder supercharged two-row air-cooled radial engine
Bore: 5.5 in (139.7 mm)
Stroke: 6.0 in (152.4 mm)
Displacement: 1,995 in³ (32.7 l)
Length: 64.6 in (1,641 mm)
Diameter: 50.8 in (1,290 mm)
Dry weight: 1,287 lb (584 kg)
Valvetrain: Two pushrod-actuated valves per cylinder
Supercharger: Two-speed centrifugal type supercharger, first gear ratio 5.34:1, second gear 7.96:1.
Fuel system: Claudel-Hobson carburettor
Fuel type: 87 octane rating petrol
Cooling system: Air-cooled
Reduction gear: Spur, 0.594:1
Power output:
907 hp (677 kW) at 2,375 rpm for takeoff
850 hp (634 kW) at 2,450 rpm at 7,150 ft (2,180 m) – first supercharger gear
771 hp (575 kW) at 2,450 rpm at 16,240 ft (4,950 m) – second supercharger gear
582 hp (434 kW) at 2,200 rpm economy cruise
Specific power: 0.45 hp/in³ (20.7 kW/l)
Compression ratio: 6.25:1
Specific fuel consumption: 0.49 lb/(hp•h) (294 g/(kW•h))
Oil consumption: 0.21–0.42 oz/(hp•h) (8–16 g/(kW•h))
Power-to-weight ratio: 0.70 hp/lb (1.16 kW/kg)
The Serval was a ten-cylinder, double-row, air-cooled radial piston engine. It was developed from the Armstrong Siddeley Mongoose and was, more or less, two Mongooses built around a single crankcase. In fact, it first appeared as the Double Mongoose in May 1928.
Built in several variants, power output was about 340 hp (254 kW).
Variants:
Serval I initially Double Mongoose
(1931) 340 hp.
Serval III
(1932)
Serval IIIB
(1932) 310 hp.
Serval IV
310 hp.
Serval V
(1933) 340 hp.
Applications:
Airco DH.9
Armstrong Whitworth Atalanta
BFW M.36
Canadian Vickers Vancouver
Fairey Fox
ICAR Comercial
Saro Cloud
Specifications:
Serval I
Type: 10-cylinder double-row radial
Bore: 5 in (127 mm)
Stroke: 5.5 in (139.7 mm)
Displacement: 1,080 cu in (17.7 L)
Length: 54.25 in (1,378 mm)
Diameter: 45.6 in (1,158 mm)
Dry weight: 714 lb (324 kg)
Valvetrain: Overhead poppet valves
Fuel type: 77 Octane petrol
Cooling system: Air-cooled
Reduction gear: Direct drive, Left hand tractor
Power output: 340 hp at 2,000 rpm at sea level
Compression ratio: 5:1
Power-to-weight ratio: 0.47 hp/lb
The Armstrong Siddeley Panther was a 27-litre 14-cylinder twin-row air-cooled radial aero engine developed by Armstrong Siddeley. First run in 1929, it was originally named the Jaguar Major.
Applications:
Armstrong Whitworth Atlas Mk II
Armstrong Whitworth A.W.XIV Starling MkII
Armstrong Whitworth A.W.16
Armstrong Whitworth A.W.35 Scimitar
Fairey Gordon
Fokker C.V
Hawker Hoopoe
Marinens Flyvebaatfabrikk M.F.11
Supermarine Air Yacht
Westland Wapiti V (first prototype)
Panther IIA
Type: 2 row 14-cyl radial
Overall diameter: 46.45 in
Length: 31.35 in
Bore 5.25 in
Stroke: 5.5 in
Compression ratio: 5-1
Reduction gear: Epicyclic .657-1
Crankshaft rotation: left hand tractor
Airscrew shaft rotation: left hand tractor
Normal crankshaft rpm: 2000
Max crankshaft rpm: 2300
Rated altitude: 3000 ft
BHP normal rpm 3000 ft: 535
BHP max rpm 3000 ft: 600
Dry weight: 1004 lb
Oil spec: Spec. D.T.D. 109
Oil consumption 90% pwr normal rpm: 12-16 pint/hr
Normal oil pressure: 50 lb/sq.in
Min permissible oil pressure: 30 lb/sq.in
Oil release valve lifts at: 65 lb/sq.in
Min outlet oil temp before flight: 15 deg C
Oil circulation: 3-5 gal/min
Carburetter: 1 x Claudel-Hobson A.V.T.70.H
Fuel consumption 90% pwr: .535 pints/BHP/hr
Spark plugs: 2 x Lodge A2
Plug gap: .012 – .015 in
Magnetos: 2 x B.T.H. SC.14-1A
Firing order: 1R, 2F, 3R, 4F, 5R, 6F, 7R, 1F, 2R, 3F, 4R, 5F, 6R, 7F
Panther VII
Type: 14-cylinder twin-row air-cooled radial engine
Bore: 5.25 in (133.4 mm)
Stroke: 5.5 in (139.7 mm)
Displacement: 1,667 cu in (27.3 L)
Length: 64 in (1.63 m)
Diameter: 46.45 in (1.18 m)
Dry weight: 1,047 lb (475 kg)
Valvetrain: Overhead valve
Supercharger: Fully supercharged
Fuel system: Carburettor
Cooling system: Air-cooled
Power output: 638 hp (478 kW) at 2,400 rpm with 0.5 psi (3.5 kPa) boost
Compression ratio: 5.1:1
Power-to-weight ratio: 0.61 hp/lb (1.01 kW/kg)
The Armstrong Siddeley Ounce was a small two-cylinder aero engine developed by Armstrong Siddeley in 1920. The engine was originally conceived as a test piece but ran very well and was put into production for early ultralight aircraft and use in target drones. The Ounce used two cylinders from the preceding Jaguar I radial engine.
Applications:
Bristol Babe
R.A.E. Aerial Target
Ounce
Type: Two cylinder, horizontally-opposed air cooled piston engine
Bore: 5.0 in (127 mm)
Stroke: 5.0 in (127 mm)
Displacement: 196 cu in (3.2 L)
Length: 20.5 in (521 mm)
Width: 39.5 in (1003 mm)
Height: 24.5 in (622 mm)
Dry weight: 170 lb (77 kg)
Valvetrain: Overhead valve
Fuel system: Carburettor
Cooling system: Air cooled
Power output: 45 hp (33.5 kW) at 1,500 rpm
Compression ratio: 5:1
Power-to-weight ratio: 0.26 hp/lb (0.43 kW/kg)
The Armstrong Siddeley Mongoose is a British five-cylinder, single-row, air-cooled radial aero engine produced by Armstrong Siddeley.
First run in 1926, it was used in the Hawker Tomtit trainer and Parnall Peto seaplane amongst others.
The engine features twin forward-mounted ignition magnetos and enclosed valve rockers, the cylinders being the same as those used for the earlier Jaguar engine. An unusual feature of the Mongoose is the vertical position of the lower cylinder, a design thought likely to promote oil fouling of the spark plugs.
Built in several variants, power output ranged between 135 and 155 hp (100-115 kW).
With a displacement of 540 cubic inches (9 litres) the Mongoose had a maximum power output of 155 horsepower (115 kilowatts).
The Mongoose was later developed into the Serval.
Variants:
Mongoose I
1926, 135 hp.
Mongoose II
1930, 155 hp.
Mongoose III
1929.
Mongoose IIIA
1929, civil use.
Mongoose IIIC
1929, Military use based on IIIA.
Applications:
Avro 504N
Avro 504R
Avro Tutor
Avro Type 621 Trainer
Handley Page Hamlet
Handley Page Gugnunc
Hawker Tomtit
Parnall Peto
Specifications:
Mongoose I
Type: 5-cylinder single-row radial
Bore: 5 in (127 mm)
Stroke: 5.5 in (139.7 mm)
Displacement: 540 cu in (8.9 L)
Length: 36.6 in (93 cm)
Diameter: 45.6 in (116 cm)
Dry weight: 340 lb (154 kg)
Valvetrain: Overhead poppet valves
Fuel type: 77 Octane petrol
Cooling system: Air-cooled
Reduction gear: Direct drive, left-hand tractor
Power output: 138 hp (103 kW) at 1,750 rpm at sea level
Compression ratio: 5:1
Power-to-weight ratio: 0.4 hp/lb (0.67 kW/kg)
All Aero 