In 1941 the United States Army Air Forces ordered four Taylorcraft Ds with the designation YO-57. They were evaluated in the summer of 1941 during maneuvers in Louisiana and Texas where they were used for support purposes such as light transport and courier. General Innis P. Swift, commander of the 1st Cavalry Division, coined the 'grasshopper' name after witnessing a bumpy landing. This led to a production order under the designation O-57 Grasshopper. In March 1942, the designation was changed to L-2 Grasshopper.

In World War II, the AAF began using the L-2 in much the same manner as the observation balloon was used in France during World War I—spotting enemy troop and supply concentrations and directing artillery fire on them. It was also used for other types of liaison and transport duties and short-range reconnaissance which required airplanes that could land and take off in minimum distances from unprepared landing strips.

Postwar, a number of L-2s were converted for civilian use and are operated by private pilot owners in the United States as the Model DCO-65. Several are still airworthy in 2011.

The L-2 series meet the standards for Light Sport Aircraft (other than the L-2M, which has a gross weight rating 5 pounds over the 1,320-lb limit), thus can be flown by pilots holding the Sport Pilot Certificate.

For details of the 20 variants, click here.

The Link Trainer,  or Pilot Trainer, was the world's first commercially built flight simulator. It was designed and built by Edwin Albert Link in the 1930s. The Link Trainer would form an integral part of pilot training programmes the world over and was instrumental for the final Allied victory during WW2. Over 10,000 Link trainers were manufactured during the Second World War and were used by almost every country. Just over 170 were employed by the RAAF for training.

Edwin Link wanted to fly, but found that his instructors were not good at teaching, so that the high cost of training was being wasted. He reasoned that if there was a way to replicated the basic movements of an aircraft flying, but without the flying bit, students could be taught to fly at a greatly reduced cost. At the time he was working for the family's Link Piano and Organ Company. There he became expert in the design and use of bellows systems to control movement.

In 1931, he received U.S Patent 1825462 in which he described his invention.

You can read the whole Patent description here: https://patents.google.com/patent/US1825462A/en

http://www.vintagewings.ca/Portals/0/Vintage_Stories/ArchivedStories/Link3.jpg 

Due to the Depression, sales of the trainer to flying schools were virtually non-existent, so, as indicated in the Patent, he attached a coin operated mechanism to the trainer and sold them to amusement parks. By 1934, he was running out of money. So, he made contact with the US Army Air Corps, pleading for the opportunity to demonstrate his technology. The Corps agreed and on "the" day, Ed took off from Binghamton and flew to the field at Newark, NJ, landing in a "pea soup" fog without incident!  The Corps soon followed with an $21,000 order for 6 simulators and Ed was "on his way".

The value to pilot training soon proved itself as WWII placed extreme demand on pilot training, not only in the USA, but throughout the world. Prior to the start of the war, Link sold his trainers to both Germany and Japan, so it would seem obvious that pilots from the Axis Powers did their instrument flying training in Link trainers.

USE BY THE RAAF

Throughout the ages, the number 13 has been shunned by the superstitious as an ill omen. Many air forces purposely delete the numeral from aircraft serials, but the RAAF overcame the problem by allotting "dat ol' devil number" to the ground-operated Link Trainer. In the RAAF, pilots logged time in aircraft type A13. Early RAAF versions included the Mks D, D2, and ANT18, of which 140 were acquired, mainly during World War II Consequently, an uncontrolled spin or an accidental crash would result in nothing more than a red-faced student who could benefit by his mistake. The history of individual RAAF Link Trainers can be found here: http://www.adf-serials.com.au/2a13.htm

This video gives a good account of the history of the Link Trainer: https://www.youtube.com/watch?v=CeWrKjkL-os&t=627s

This is the panel the student looked at

The simulated performance figures in terms of Never Exceed speed, Rate of Climb, Cruise speed etc might be found in the operating manual. As the Link Trainer was used during the early stages of flight training, these values might be expected to mimic those of the typical flying training aircraft.

Flight missions were planned and controlled by the Simulator Instructor who could add factors such as wind direction and strength and turbulence as the student gained experience. A feature of the instructor's control was a device called a "crab" which was a three-wheeled device that would respond to airspeed and direction inputs from the Link's pilot's controls and track across a map to produce a record of the "flight"

The Timm N2T Tutor is an American training monoplane built by the Timm Aircraft Corporation for the United States Navy as the N2T-1.

The Timm S-160 (or Timm PT-160K) was a conventional tandem open-cockpit monoplane trainer first flown on the 22 May 1940 by test pilot Vance Breese. It was powered by a Kinner R-5 radial engine and was a low-wing cantilever monoplane with a tailwheel landing gear. It had an unusual feature in that the airframe structure was made from resin impregnated and molded plywood, creating a composite material stronger and lighter than plywood. This process was patented as the Nuyon process and marketed as the aeromold process. The S-160 received the first approval for a plastic-wood construction, (ATC #747), on 28 August 1941.

The PT-175-K variant was fitted with a Kinner R-53 engine. This was followed by the PT-220-C with a 220 hp (164 kW) Continental W-670-6 engine and larger tail.

The PT-220C was evaluated by the United States Navy, which ordered 262 aircraft in 1943 as the N2T-1, incorporating only slight changes from the prototypes. The N2T-1 was a U.S. Navy basic trainer which the Navy nicknamed "Tiny Timm." The entire initial order was delivered in 1943 with no follow-on contract due to the military placing too many orders for Army and Navy trainers.

Although popular and relatively reliable, the N2T-1 was not built for long-term use, especially being made almost entirely of a wood based composite material that proved to be susceptible to decomposing. Postwar, the N2T was sold to private owners and 10 remained on the U.S. civil aircraft register in 2001.

Variants

PT-160-K (ATC#747)
Version with a 160 hp (119 kW) Kinner R-5 engine.
PT-175-L
Version with a 175 hp (130 kW) Kinner R-53 engine.
PT-220-C (ATC#750)
Version with a 220 hp (164 kW) Continental W-670-6 engine.
N2T-1
Production version of the PT-220C for the United States Navy, 262 built.

The Tupolev Tu-28 (NATO reporting name Fiddler) was a long-range interceptor aircraft introduced by the Soviet Union in the 1960s. The official designation was Tu-128, but this designation was less commonly used in the West. It was the largest and heaviest fighter ever in service.

Iosif Nezval, of Tupolev Design Bureau. led development of the new interceptor aircraft. The work began in 1958, based on an existing single prototype of the unsuccessful Tu-98 supersonic bomber. The military designation of the interceptor was at first Tu-28, but it was changed in 1963 to Tu-128, identical to the designation used by the OKB.

The Tu-128 had a broad, low/mid-mounted swept wing carrying the main landing gear in wing-mounted pods, and slab tailplanes. Two Lyulka AL-7F-2 turbojet engines were mounted in the fuselage. The two-man crew of pilot and navigator were seated in tandem.

The Tu-128, with its maximum weight of 43 tonnes, was the heaviest fighter to enter service. It was an interceptor with high wing loading, unsophisticated but reliable avionics and poor visibility. It was not an agile aircraft, intended only to combat NATO bombers like the B-52 not engage in dogfights with smaller aircraft.

The interceptor made its initial public appearance in the 1961 Tushino air parade. Western experts, unaware that the bulge on the belly carried testing instruments, mistook it for a large ventral radar for a mixed interceptor/AWACS role.[3] The production version lacked the bulge and had a large nose radome housing a radar, known as RP-S[nb 4] Smerch, having a detection range of about 50 km (31 mi) and a lock-on range of about 40 km (25 mi).

Armament of the Tu-128 was four Bisnovat R-4 air-to-air missiles (known as K-80 during development; NATO reporting name AA-5 'Ash'). Usually two of them were R-4Rs with semi-active radar homing and two were R-4T infrared-homing missiles, with the former on the outer pylons and the latter on the inner underwing pylons. There was no internal weapons bay.

Production of the Tu-128 ended in 1970 with a total of 198 aircraft having been built.

Development of various projects designated Tu-28A, Tu-28-80, Tu-28-100, Tu-138, and Tu-148 were proposed by the Tupolev Design Bureau but all were abandoned.

For background, operational history and variants, click here.

The Tupolev Tu-2 (development names ANT-58 and 103; NATO reporting name Bat) was a twin-engine Soviet high-speed daylight and frontline (SDB and FB) bomber aircraft of World War II vintage. The Tu-2 was tailored to meet a requirement for a high-speed bomber or dive-bomber, with a large internal bombload, and speed similar to that of a single-seat fighter. Designed to challenge the German Junkers Ju 88, the Tu-2 proved comparable, and was produced in torpedo, interceptor, and reconnaissance versions. The Tu-2 was one of the outstanding combat aircraft of World War II and it played a key role in the Red Army's final offensives.

In 1937, Andrei Tupolev, along with many Soviet designers at the time, was arrested on trumped-up charges of activities against the State. Despite the actions of the Soviet government, he was considered important to the war effort and following his imprisonment, he was placed in charge of a team that was to design military aircraft. Designed as Samolyot (Russian: "aircraft") 103, the Tu-2 was based on earlier ANT-58, ANT-59 and ANT-60 light bomber prototypes. Essentially an upscaled and more powerful ANT-60 powered by AM-37 engines, the first prototype was completed at Factory N156, and made its first test flight on 29 January 1941, piloted by Mikhail Nukhtinov. Mass production began in September 1941, at Omsk Aircraft Factory Number 166, with the first aircraft reaching combat units in March 1942. Modifications were made based on combat experience, and Plant Number 166 built a total of 80 aircraft. The AM-37 engine was abandoned to concentrate efforts on the AM-38F for the Il-2, which required Tupolev to redesign the aircraft for an available engine. Modifications of this bomber to the ASh-82 engine as well as improving the general design for simpler manufacturing took well into 1943 with production restarting in late 1943. Wartime production of the new variant was about 800 aircraft (up to June 1945) with an overall production of 2460 aircraft until 1952, the majority of them by aircraft factory number 23 in Moscow.

Built from 1941 to 1948, the Tu-2 was the USSR's second most important twin-engine bomber (the first being the Pe-2). The design brought Andrei Tupolev back into favour after a period of detention. Crews were universally happy with their Tupolevs. Pilots could maneuver the aircraft like a fighter, it could survive heavy damage, and it was fast. The first Soviet unit to be equipped with the Tu-2 was 132 BAP of 3 VA (Vozdushnaya Armiya, Air Army). The aircraft had its baptism of fire over Velikiye Luki. There, in November–December 1942, this Tupolev bomber flew 46 sorties. On February 11, 1943, 132 BAP was transferred to 17 VA to support the drive toward River Dnepr and it flew another 47 sorties - attacking airfields and rail junctions - until April 13, when the unit was removed from frontline. By that time only three Tu-2s were lost in action, while seven were damaged. The Tu-2 remained in service in the USSR until 1950.

Some surplus Tu-2s were provided to the Chinese People's Liberation Army Air Force for use in the Chinese Civil War. Some Chinese Tu-2s were shot down by United Nations airmen during the Korean War. In the 1958–1962 'counter-riot actions' in the 1959 Tibetan uprising in Qinghai-Tibet Plateau covering Qinghai, Tibet, southern Gansu, and western Sichuan, Chinese PLAAF Tu-2s took on the roles of ground-attack, reconnaissance and liaison. The Chinese Tu-2s were retired at the end of the 1970s.

After World War II, the Tu-2 proved to be an ideal test aircraft for various powerplants, including the first generation of Soviet jet engines.

For the long list of variants, click here.

The Vickers Type 56 Victoria was a British biplane freighter and troop transport aircraft used by the Royal Air Force. The Victoria flew for the first time in 1922 and was selected for production over the Armstrong Whitworth Awana.

The Victoria was a twin-engined biplane transport with a conventional landing gear with a tailskid. The design mated a similar fuselage of the earlier Vernon transport with the wing of the Virginia bomber, which was developed in parallel. It was also powered by two Napier Lion engines. The enclosed cabin had room for 24 troops on collapsible canvas seats arranged along the sides of the fuselage.

In April 1921 two prototypes were ordered by the Air Ministry to Specification 5/20. The first prototype, allocated serial number J6860, was built as a Type 56 and designated as Victoria I, the second J6861 was built as a Type 81 Victoria II. The Type 56 had two 450 hp (340 kW) Napier Lion engines with large frontal radiators and were fitted directly onto the lower mainplanes, the fuel tanks were placed under the inboard section of the bottom mainplane. The prototype J6860 first flew from Brooklands, Surrey on 22 August 1922. The Type 81 flew in January 1923, and initially differed only in having the fuel tanks under the top mainplane.[5] It was later modified by replacing the flat sided engine cowling with more streamlined nacelles with the radiators between the undercarriage legs, as fitted in the Virginia II bomber.

In March 1925, it was decided to place an order for 15 production aircraft. By this time, the Virginia design had evolved to incorporate swept-back wings, and the production Victoria IIIs incorporated this change. Another improvement first introduced in the Virginia was the introduction of metal structures instead of the all-wooden airframes of the early aircraft, with an order being placed for a prototype Victoria with a metal structure (serial number J9250) in September 1927, this being delivered in October 1928. The metal airframe proved much more suitable for the hot and humid areas where the Victoria served, with Victoria IV and Vs with metal structures produced by conversion and new production respectively. The final version was the Mark VI, which substituted modern, more powerful Bristol Pegasus radial engines for the Napier Lions. The Vickers Valentia was a further improved version with a stronger structure, capable of operating at higher weights.

97 Victorias were built, many of which were later converted into Valentias.

Variants

Type 56 Victoria Mk I
The first prototype. Powered by two 450 hp (340 kW) Napier Lion IAX W12 engines.
Type 81 Victoria Mk II
The second prototype.
Type 117 Victoria Mk III
The first production version. Military transport aircraft for the RAF. Powered by 450 hp Napier Lion II engines. 46 built.
Type 145 Victoria Mk IV
Metal wing structure. One prototype powered by Bristol Jupiter radials.[19] Thirteen Lion-engined conversions from earlier marks.
Type 169 Victoria Mk V
New production aircraft with metal structure, powered by two 570 hp (430 kW) Napier Lion XIB engines. 37 new-built.
Type 262 Victoria Mk VI
Final production - powered by 660 hp (490 kW) Bristol Pegasus IIL3 engines instead of Lions. 11 new-build, 23 by conversion.

The Vickers Warwick was a British twin-engined bomber aircraft developed and operated during the Second World War that was primarily used in other roles. In line with the naming convention followed by other RAF heavy bombers of the era, it was named after a British city or town, in this case Warwick. The Warwick was the largest British twin-engined aircraft to see use during the Second World War.

The Warwick was designed and manufactured by Vickers-Armstrongs during the late 1930s. It was intended to serve as a larger counterpart to the Vickers Wellington bomber. The two aircraft share similar construction and design principles but development of the Warwick was delayed by a lack of suitable engines. Its first flight was on 13 August 1939 but delays to its intended powerplant and by the time adequate engines were available, it was obsolete.

The Warwick entered production during 1942 and squadron service with the Royal Air Force (RAF). Barely a dozen aircraft were built as bombers. The type was used by RAF Transport Command as a transport, and by RAF Coastal Command as an air-sea rescue and maritime reconnaissance aircraft. The Warwick was also operated by the Polish Air Forces in exile in Great Britain and the South African Air Force. A civil operator, the British Overseas Airways Corporation (BOAC), also operated a handful of transport Warwicks.

In October 1932, the British industrial conglomerate Vickers-Armstrongs tendered for the Air Ministry Specification B.9/32, which called for the development of a twin-engined medium bomber. During late 1934, when the company was already developing their Type 271 to meet Specification B.9/32, Vickers received a draft requirement for a larger bomber. The draft specification developed into Air Ministry Specification B.1/35, which sought a twin-engined heavy strategic bomber. It was intended to make use of more powerful engines, of 1,000 hp (750 kW), that were being developed, to enable the bomber to be faster and carry a heavier bomb load than the earlier B.3/34. Among the requirements of Specification B.1/35 was a speed of no less than 195 mph (314 km/h) while flying at 15,000 ft (4,600 m), a range of 1,500 mi (2,400 km) while carrying 2,000 lb (910 kg) of bombs, and the engines were to be furnished with variable-pitch propellers.

It was designed in parallel with the smaller Wellington, both aircraft having been derived from the Vickers Type 271 design, developed for Specification B.9/32. By the end of July 1935, the Air Ministry was considering eight designs. These included Vicker's proposal, the Type 284, powered by a pair of Bristol Hercules engines, which exceeded the specifications. Vickers received an order for a prototype on 7 October 1935, while the Air Ministry also ordered prototypes from Armstrong Whitworth (the AW.39, a development of the Armstrong Whitworth Whitley) and Handley Page (the HP.55). These alternative designs were cancelled before being built, as Handley Page and Armstrong Whitworth switched to work on newer specifications released for medium (P.13/36) and heavy (B.12/36) bombers.

For more details of development and design, operational history and 12 variants, click here.

Total number built was 846.

The Vickers Wellesley was a medium bomber that was designed and produced by the British aircraft manufacturer Vickers-Armstrongs at Brooklands near Weybridge, Surrey. It was one of two aircraft to be named after Arthur Wellesley, 1st Duke of Wellington, the other being the Vickers Wellington.

The Wellesley was developed during the early 1930s in response to Specification G.4/31. The biplane Vickers Type 253 was effectively an early incarnation of the aircraft, sharing its radical geodesic airframe and many other features. The Type 253 was determined to be the best submission received by the Air Ministry, thus an order for 150 production aircraft was issued. As a private venture, Vickers has also developed the monoplane Type 256; following flight testing of this aircraft, the order placed for the Type 253 was converted for the Type 256 instead.

The vast majority of the Wellesley's production run were supplied to the Royal Air Force (RAF), a total of six squadrons under RAF Bomber Command operated the type at its peak. A high-profile demonstration of the aircraft's capabilities was conducted during early November 1938 via a flight of three Wellesleys that flew non-stop for two days from Ismailia, Egypt to Darwin, Australia, a distance of 7,162 miles (11,526 km), setting a world distance record in the process. While the type was considered to be obsolete by the start of the Second World War and thus unsuited to the European air war, the Wellesley was operated overseas in the desert theatres of East Africa, Egypt and the Middle East. The final Wellesley-equipped unit, 47 Squadron, ended its use of the type as a maritime reconnaissance aircraft, during September 1942.

The Wellesley was a single-engine monoplane with a very high 8.83 aspect ratio wing and a manually operated, retractable undercarriage. As it was not known how the geodetic structure could cope with being disrupted by a bomb bay, the Wellesley's bomb load was instead carried in a pair of streamlined panniers underneath the wings. The Wellesley Mk I had two cockpits but this was slightly changed in what was unofficially dubbed the Wellesley Mk II, whose pilot's canopy was extended to cover the navigator/bomb aimer's position that had been buried in the fuselage. The gunner retained a separate canopy. Only the pilot was provided with flight controls. The aircraft was furnished with a three-axis autopilot.

Number built    177

For more det ails of background, development, operational history and eight variants, click here.

A key feature of the aircraft is its geodetic airframe fuselage structure, which was principally designed by Barnes Wallis.

 Development had been started in response to Air Ministry Specification B.9/32, issued in the middle of 1932, for a bomber for the Royal Air Force. This specification called for a twin-engined day bomber capable of delivering higher performance than any previous design. Other aircraft developed to the same specification include the Armstrong Whitworth Whitley and the Handley Page Hampden. During the development process, performance requirements such as for the tare weight changed substantially, and the engine used was not the one originally intended.

 The Wellington was used as a night bomber in the early years of the Second World War, performing as one of the principal bombers used by Bomber Command. During 1943, it started to be superseded as a bomber by the larger four-engined "heavies" such as the Avro Lancaster. The Wellington continued to serve throughout the war in other duties, particularly as an anti-submarine aircraft.

It holds the distinction of having been the only British bomber that was produced for the duration of the war, and of having been produced in a greater quantity than any other British-built bomber. The Wellington remained as first-line equipment when the war ended, although it had been increasingly relegated to secondary roles. The Wellington was one of two bombers named after Arthur Wellesley, 1st Duke of Wellington, the other being the Vickers Wellesley.

Number built:   11,461

For more details including the 42 variants, click here.

Rear fuselage showing geodetic construction.

The VL Myrsky ("Storm") is a Finnish World War II fighter aircraft originally developed by Valtion lentokonetehdas for the Finnish Air Force. The models of the aircraft were Myrsky I, Myrsky II, and Myrsky III.

It was designed by Edward Wegelius, Martti Vainio and Torsti Verkkola who worked at Valtion lentokonetehdas.

The decision to start developing a new fighter for the Finnish Air Force was based on experience gained before the Winter War: in the "arms race" leading up to a war, smaller nations can have difficulty purchasing top-of-the-line fighters without a significant political cost. The Finnish Air Force requested preliminary proposals for a domestic fighter from State Aircraft Factory (Valtion Lentokonetehdas) in early 1939, before the Winter War. State Aircraft Factory prepared five alternative proposals by May 1939. After that, The Ministry of Defence ordered the fighter design from State Aircraft Factory in June 1939.

The preliminary design was made by the aircraft-designer trio Arvo Ylinen (head of the design-bureau), Martti Vainio (aerodynamics), and Torsti Verkkola (structural design). Edward Wegelius was appointed head of the design department of the State Aircraft Factory when Ylinen later moved on to the Helsinki University of Technology in August 1940. VL did not appoint any main constructor to its products, such as the German aircraft manufacturers did.

Due to difficulties obtaining duraluminium, the wings were made out of plywood and the fuselage was metal structure with a fabric and plywood skin. The planned Bristol Taurus III engine was not available due to war, so a Pratt & Whitney R-1830 (civil Twin Wasp) was chosen. Availability of this engine was also problematic, so the first prototype used an R-1830-S3C3-G, while later prototypes and production fighters used less-powerful SC3-Gs. Finland bought these engines from German war booty stocks.

The first Myrsky prototype flew on 23 December 1941. The prototype was fully functional, but too heavy. After some modifications they soon had three new prototype aircraft. The test flights showed some structural problems during high-speed tests. All three prototypes were destroyed during test flights; two test pilots died, one was seriously injured. The culprit was found to be aeroelastic flutter, which was a poorly known phenomenon at the time. Resolving the flutter problem took almost a year.

Series production started in autumn 1942 far before German deliveries of Messerschmitt Bf 109 had begun in 1943. The series production version was called the Myrsky II. 47 Myrsky IIs were built and together with the Myrsky I version and Myrsky prototype the production amounted to 51 in all. Although the aircraft met the specifications set for it, it did not fulfill all expectations due to structural problems. or operational history, click here.

The Myrsky III was ordered in spring 1943, but none were built. 

Variants

Myrsky
Prototype, 1 built
Myrsky I
Preproduction aircraft, 3 built
Myrsky II   (Specifications below)
Series-production aircraft, 47 built
Myrsky III
10 being built but cancelled

Designed and initially manufactured by Chance Vought, the Corsair was soon in great demand; additional production contracts were given to Goodyear, whose Corsairs were designated FG, and Brewster, designated F3A.

The Corsair was designed and operated as a carrier-based aircraft, and entered service in large numbers with the U.S. Navy in late 1944 and early 1945. It quickly became one of the most capable carrier-based fighter-bombers of World War II. Some Japanese pilots regarded it as the most formidable American fighter of World War II and its naval aviators achieved an 11:1 kill ratio. Early problems with carrier landings and logistics led to it being eclipsed as the dominant carrier-based fighter by the Grumman F6F Hellcat, powered by the same Double Wasp engine first flown on the Corsair's first prototype in 1940. Instead, the Corsair's early deployment was to land-based squadrons of the U.S. Marine Corps and U.S. Navy.

The Corsair served almost exclusively as a fighter-bomber throughout the Korean War and during the French colonial wars in Indochina and Algeria. In addition to its use by the U.S. and British, the Corsair was also used by the Royal New Zealand Air Force, French Naval Aviation, and other air forces until the 1960s.

From the first prototype delivery to the U.S. Navy in 1940, to final delivery in 1953 to the French, 12,571 F4U Corsairs were manufactured in 16 separate models. Its 1942–1953 production run was the longest of any U.S. piston-engined fighter.

For details of deveopment, design, operational history and variants, click here.

The Vought F6U Pirate was the Vought company's first jet fighter, designed for the United States Navy during the mid-1940s. Although pioneering the use of turbojet power as the first naval fighter with an afterburner and composite material construction, the aircraft proved to be underpowered and was judged unsuitable for combat. None were ever issued to operational squadrons and they were relegated to development, training, and test roles before they were withdrawn from service in 1950.

A specification was issued by the Navy's Bureau of Aeronautics (BuAer) for a single-seat, carrier-based fighter powered by a Westinghouse 24C (later J34) axial turbojet on 5 September 1944. Chance Vought was awarded a contract for three V-340 (company designation) prototypes on 29 December 1944.

The XF6U was a small aircraft with tricycle undercarriage and with straight wings and tail surfaces. The wings were short enough that folding wings were not used to reduce the aircraft's footprint on a carrier deck. To fit more aircraft into crowded hangars, the nose gear could be retracted and the aircraft's weight would rest on a small wheel attached by the ground crew. This raised the tail up so that it could overlap the nose of the aircraft behind it, allowing more aircraft to fit into available hangar space. The turbojet engine was mounted in the rear fuselage and was fed by ducts in each wing root.

The most unusual feature of the aircraft was its use of "Metalite" for its skin. This was made of balsa wood, sandwiched between two thin sheets of aluminum. "Fabrilite" was also used for the surfaces of the vertical stabilizer and rudder; this was similar to Metalite but used fiberglass instead of aluminum. Two fuel tanks were fitted in the center of the fuselage; the forward tank, ahead of the wing, contained 220 US gallons (830 L; 180 imp gal) and the rear tank, 150 US gallons (570 L; 120 imp gal). These were supplemented by two jettisonable 140-US-gallon (530 L; 120 imp gal) tip tanks. The cockpit was well forward and was provided with a bubble canopy which gave the pilot good visibility. He was provided with a Mk 6 lead-computing gyro gunsight. Underneath the cockpit were four 20 mm (0.79 in) M3 autocannon. Their 600 rounds of ammunition were carried behind the pilot. The empty casings of the two upper guns were retained in the aircraft, while those from the two lower guns were ejected overboard.

After a company-wide contest to name the aircraft, the initial prototype received the name Pirate and made its first flight on 2 October 1946. Flight testing revealed severe aerodynamic problems, mostly caused by the airfoil section and thickness of the wing. The vertical stabilizer also had to be redesigned to smooth out the airflow at the intersection of the horizontal and vertical stabilizers. Other changes included the addition of dive brakes on the sides of the fuselage and the replacement of the Metalite panels near the engine exhaust with stainless steel ones.

The first XF6U-1 prototype was powered by a Westinghouse J34-WE-22 turbojet with 3,000 lbf (13.34 kN) thrust, one third of the weight of the aircraft. To help improve the underpowered aircraft's performance, the third prototype, which first flew on 10 November 1947, was lengthened by 8 feet (2.4 m) to use a Westinghouse J34-WE-30 afterburning engine of 4,224 lbf (18.78 kN) thrust, the first United States Navy fighter to have such a powerplant.

Variants

XF6U-1: Three prototypes, two with a Westinghouse J34-WE-22 turbojet engine (BuNo 33532, 33533), one with a J34-WE-30 with afterburner (BuNo 33534).
F6U-1: Afterburner-equipped production version, 30 built (BuNo 122478-122507), 35 cancelled.
F6U-1P: Conversion of one F6U-1 (BuNo 122483) for photo-reconnaissance.

The Vought OS2U Kingfisher is an American catapult-launched observation floatplane. It was a compact mid-wing monoplane, with a large central float and small stabilizing floats. Performance was modest because of its low-powered engine. The OS2U could also operate on fixed, wheeled, taildragger landing gear.

The OS2U was the main shipboard observation seaplane used by the United States Navy during World War II, and 1,519 of the aircraft were built. It served on battleships and cruisers of the US Navy, with the United States Marine Corps in Marine Scouting Squadron Three (VMS-3), with the United States Coast Guard at coastal air stations, at sea with the Fleet Air Arm of the Royal Navy, and with the Soviet Navy. The Royal Australian Air Force also operated a few Kingfishers from shore bases.

The Naval Aircraft Factory OS2N was the designation of the OS2U-3 aircraft built by the Naval Aircraft Factory in Philadelphia, Pennsylvania. The OS2U first flew on 1 March 1938.

In the late 1930s, Vought engineer Rex B. Beisel was tasked with designing an observation monoplane aircraft for the U.S. Navy suitable for many tasks, including directing battleship fire. In replacing the standard biplane observation aircraft with a more modern monoplane design, Beisel incorporated innovations making it the first production type to be assembled with spot welding, a process Vought and the Naval Aircraft Factory jointly developed to create a smooth fuselage that resisted buckling and generated less drag. Beisel also introduced high-lift devices, spoilers and in a unique arrangement, deflector plate flaps and drooping ailerons located on the trailing edge of the wing were deployed to increase the camber of the wing and thus create additional lift.

For combat missions, the pilot had a .30-caliber Browning M1919 machine gun, the receiver mounted low in the right front cockpit, firing between the engine cylinder heads, while the radio operator/gunner manned another .30-caliber machine gun (or a pair) on a flexible Scarff ring mount. The aircraft could also carry two 100 lb bombs or two 325 lb depth charges. Additionally, the "Kingfisher", as it was designated, served as a trainer in both its seaplane and landplane configurations.

Beisel's first prototype flew in 1938, powered by an air-cooled, 450 hp Pratt & Whitney R-985-4 Wasp Junior radial engine.

In April 1942 The Royal Australian Air Force (RAAF) obtained 18 Kingfishers from an unexpected source.  These aircraft had been destined for the Royal Netherlands Air Force, for operation in the Netherlands East Indies, but following the capture of that area by the Japanese in March 1942 the crated aircraft were diverted to Australia.  The Kingfishers were allocated to 107 Squadron and operated from RAAF Base Rathmines on the Australian east coast conducting anti-submarine patrols and seaplane flight training duties. At wars end the remaining nine aircraft were flown to the RAAF Base at Lake Boga, Victoria for storage.

For more details on the operational history and variants of the Kingfisher, click here, and for details of its service in the RAAF/RAN, click here.

The Vought SB2U Vindicator is an American carrier-based dive bomber developed for the United States Navy in the 1930s, the first monoplane in this role. Vindicators still remained in service at the time of the Battle of Midway, but by 1943, all had been withdrawn to training units. It was known as the Chesapeake in Royal Navy service.

In 1934, the United States Navy issued a requirement for a new Scout Bomber for carrier use, and received proposals from six manufacturers. The specification was issued in two parts, one for a monoplane, and one for a biplane. Vought submitted designs in both categories, which would become the XSB2U-1 and XSB3U-1 respectively. The biplane was considered alongside the monoplane design as a "hedge" against the U.S. Navy's reluctance to pursue the modern configuration.

The XSB2U-1 was of conventional low-wing monoplane configuration with a retractable conventional tailwheel landing gear, the pilot and tail gunner being seated in tandem under a long greenhouse-style canopy. The fuselage was of steel tube construction, covered with aluminum panels from the nose to the rear cockpit with a fabric-covered rear fuselage, while the folding cantilever wing was of all-metal construction. A Pratt & Whitney R-1535 Twin-Wasp Junior radial engine drove a two-blade constant-speed propeller, which was intended to act as a dive brake during a dive bombing attack. The use of propeller braking was not entirely successful, and in practice US Navy Vindicators lowered the aircraft's undercarriage to act as a speed brake and dived at shallower angles. A single 1,000 lb (450 kg) bomb could be carried on a swinging trapeze to allow it to clear the propeller in a steep dive, while further bombs could be carried under the wings to give a maximum bombload of 1,500 lb (680 kg).

For more details of design and development, operational history and eight variants, click here.

A modified version was designated A-35. The Vengeance was not used operationally by the United States, but was operated as a front-line aircraft by the British Royal Air Force, the Royal Australian Air Force, and the Indian Air Force in Southeast Asia and the Southwest Pacific. The A-31 remained in service with U.S. units until 1945, primarily in a target-tug role.

In 1940, Vultee Aircraft started the design of a single engined dive-bomber, the Vultee Model 72 (V-72) to meet the requirements of the French Armée de l'Air. The V-72 was built with private funds and was intended for sale to foreign markets. The V-72 was a low-wing, single-engine monoplane with a closed cockpit and a crew of two. An air-cooled radial Wright Twin Cyclone GR-2600-A5B-5 engine rated at 1,600 hp (1,200 kW) powered the V-72. It was armed with both fixed forward-firing and flexible-mounted .30 in (7.62 mm) machine guns in the rear cockpit. The aircraft also carried up to 1,500 lb (680 kg) of bombs in an interior bomb bay and on external wing racks.

Service with the RAAF (from RAAF Museum website).

The Vultee V72 dive-bomber was produced at a time when the German Air Force was having marked success with the Junkers Ju-87, or Stuka, dive-bomber. The American aircraft was first flown in July 1941, and large quantities were immediately ordered, as the Vengeance, for the RAF. When the US entered the war, a number of these aircraft were re-possessed and, in addition, Australia placed an order for 400. Export versions included Vengeance Mks I, II, and III (USAAF equivalent A-3l) and Mk IV (USAAF equivalent A-35).

In all, 342 Vengeance Mks I, II and IV operated with the RAAF under the following serials: A27-1 to A27-99, A27-200 to A27-321, A27-400 to A27-422, A27-500 to A27-549, A27-560 to A27-566 and A27-600 to A27-640. Although the first Vengeance A27-1 was received on 30 May 1942, substantial numbers did not arrive until April 1943, by which time the crisis for which they had been ordered, had passed.

RAAF Vengeances operated with Nos 12, 21, 23, 24 and 25 Squadrons and, after a somewhat indifferent career, the aircraft were withdrawn from operations following a bombing raid by 36 Vengeances on 8 March 1944 against Rempi village. At the time, 58 Vengeances were still to be delivered and, consequently, this balance from the original order was cancelled. Vengeances also operated with Nos 3, 4, 5, 6, 7 and 8 Communication Units, while others were used in the target-towing role and for experiments at No 1 Air Performance Unit.

For more information on the Vengeance, click here.

The Vultee BT-13 Valiant is a single-engine two-seat trainer aircraft produced by the US-American manufacturer Vultee Aircraft, Inc., later Consolidated Vultee Aircraft Corporation ? Convair. The Vultee Valiant was the basic trainer aircraft for the second phase of pilot training for the US Army Air Corps, later the US Army Air Forces. The BT-15 is a Wright engine powered variant. The designation in US Navy service was SNV (SNV-1 for BT-13A and SNV-2 for BT-13B). Company designation was Vultee V-74.

Vultee BT-15 N67629 Valiant "AI-201" modified to look like Aichi D3A Val for Tora! Tora! Tora!

The Waco CG-4 was the most widely used American troop/cargo military glider of World War II. It was designated the CG-4A by the United States Army Air Forces, and given the service name Hadrian (after the Roman emperor) by the British.

The glider was designed by the Waco Aircraft Company. Flight testing began in May 1942. More than 13,900 CG-4As were eventually delivered.

The CG-4A was constructed of fabric-covered wood and metal and was crewed by a pilot and copilot. It had two fixed mainwheels and a tailwheel.

The CG-4A could carry 13 troops and their equipment. Cargo loads could be a 1⁄4-ton truck (i.e. a Jeep), a 75 mm howitzer, or a 1⁄4-ton trailer, loaded through the upward-hinged nose section. Douglas C-47 Skytrains were usually used as tow aircraft. A few Curtiss C-46 Commando tugs were used during and after the Operation Plunder crossing of the Rhine in March 1945.

(17 mm) nylon, 350 feet (110 m) long. The CG-4A pickup line was 15⁄16 inch (24 mm) diameter nylon, but only 225 ft (69 m) long including the doubled loop.

In an effort to identify areas where strategic materials could be reduced, a single XCG-4B was built at the Timm Aircraft Corporation using wood for the main structure.

The 16 companies that were prime contractors for manufacturing the CG-4A were:

Babcock Aircraft Company of DeLand, Florida (60 units at $51,000 each) For details of operational history
Cessna Aircraft Company of Wichita, Kansas (750 units) The entire order was subcontracted to Boeing Aircraft Company's new Wichita plant.
Commonwealth Aircraft of Kansas City, Kansas (1470 units)
Ford Motor Company of Kingsford, Michigan (4,190 units at $14,891 each)
G&A Aircraft of Willow Grove, Pennsylvania (627 units)
General Aircraft Corporation of Astoria, Queens, New York) (1,112 units)
Gibson Refrigerator of Greenville, Michigan (1,078 units)
Laister-Kauffman Corporation of St. Louis, Missouri (310 units)
National Aircraft Corp. of Elwood, Indiana (one unit, at an astronomical $1,741,809)
Northwestern Aeronautical Corporation of Minneapolis, Minnesota (1,510 units)
Pratt-Read of Deep River, Connecticut (956 units)
Ridgefield Manufacturing Company of Ridgefield, New Jersey (156 units)
Robertson Aircraft Corporation of St. Louis, Missouri (170 units)
Timm Aircraft Company of Van Nuys, California (434 units)
Waco Aircraft Company of Troy, Ohio (1074 [999] units at $19,367 each)
Ward Furniture Company of Fort Smith, Arkansas (7 units)
The factories ran 24-hour shifts to build the gliders. 

For details of operational history and variants, click here. 

In 1927, the Advance Aircraft Company in America introduced the three-seat, open cockpit WACO 10, and the general design of this aircraft remained in production until World War II. A five-seat enclosed cabin version was produced in 1936 as the WACO YQC-6; the Y, Q and C symbols referring to engine, wing and fuselage details, whilst the 6 stood for 1936. Adastra Airways at Mascot, imported a Waco YQC-6 and the biplane appeared on the DCA register as VH-UVW. Unfortunately, on its first test flight on 30 May 1936, the Waco overturned before take-off because the wheel brakes did not fully release. Repairs were carried out and, in 1937, the Waco was transferred to Southern Airlines and Freighters Ltd for service between Sydney and Broken Hill. On 19 October 1938, the Waco was fitted with a galvanised-iron fish tank for operations with Mr N. Healy. A further change of ownership occurred on 22 May 1939, when the aircraft was taken over by Mr J. Palmer.

On 4 August 1942, the RAAF impressed Waco YQC-6, ex VH-UVW, and the aircraft was taken on strength at No 3 Communications Flight as A54-1. The following day, it was allotted to Marshall Airways for camouflaging and modification, and was returned to No 3 Communications Flight on 26 August 1942. On 6 September 1942, the Waco ground-looped on landing and the starboard lower mainplane and both spars were broken. The aircraft was subsequently repaired and overhauled, and continued to give good service at No 3 Communications Flight until 12 April 1944.

On 26 November 1944, the Waco was offered for disposal and on 9 March 1945 it was released to Mr W. Meecham as VH-UVW.

 Fuselage structure was typical for the period, being welded steel tubing with light wood strips to fair the shape in. The wings were made of spruce with two spars each, having ailerons on only the upper wings, mounted on a false spar. Split flaps were installed on the undersides of the upper wings, though two designs were used depending on model – placed either mid-chord (OC, UC and QC), or in the conventional position at the trailing edge of the wing (GC and N). The model N was unusual in being the only model with flaps on the lower wings while the model E was the only one with plain flaps. Wing bracing was with a heavily canted N strut joining upper and lower wings, assisted by a single strut bracing the lower wing to the upper fuselage longeron, except on the E series which replaced the single strut with flying and landing wires. Elevators and rudder were aerodynamically counterbalanced and braced with wire cables. Both could be trimmed, the rudder via a ground-adjustable tab, the elevators via jack screw on the OC, UC and QC, while the GC, E and N used a single trim tab on the port (left) elevator. The main landing gear was sprung with oleo struts, and a castoring tailwheel was fitted on all versions except the VN model, which had a nosewheel.

For more details on the Waco Cabin Series, including operational history and a multitude of variants, click here.

After becoming obsolete in the army co-operation role, the aircraft's exceptional short-field performance enabled clandestine missions using small, improvised airstrips behind enemy lines to place or recover agents, particularly in occupied France with the help of the French Resistance. Royal Air Force army co-operation aircraft were named after mythical or historical military leaders; in this case the Spartan admiral Lysander was chosen.

The Lysander was designed to be powered by a Bristol Mercury air-cooled radial engine and had high wings and a fixed conventional landing gear mounted on an innovative inverted U square-section tube that supported wing struts at the apex, was in itself resilient, and contained (internal) springs for the faired wheels. The large streamlined spats also each contained a mounting for a Browning machine gun and for small, removable stub wings that could be used to carry light bombs or supply canisters. The wings had a reverse taper towards the root, which gave the impression of a bent gull wing from some angles, although the spars were straight. It had a girder type construction faired with a light wood stringers to give the aerodynamic shape. The forward fuselage was duralumin tube joined with brackets and plates, and the after part was welded stainless steel tubes. Plates and brackets were cut from channel extrusions rather than being formed from sheet steel. The front spar and lift struts were extrusions. The wing itself was fabric covered, and its thickness was maximized at the lift strut anchorage location, similar to that of later marks of the Stinson Reliant high-winged transport monoplane.

A total of 1,786 Lysanders were built, including 225 manufactured under licence by National Steel Car in Toronto, Ontario, Canada during the late 1930s.

For more details of the development, design, operational history and variants of the Lysander, click here.

Specifications below are for the lysander Mk III variant.

The Westland Wapiti was a British two-seat general-purpose military single-engined biplane of the 1920s. It was designed and built by Westland Aircraft Works to replace the Airco DH.9A in Royal Air Force service.

First flying in 1927, the Wapiti entered service with the RAF in 1928, and remained in production until 1932, a total of 565 being built. It equipped twenty squadrons of the RAF, both overseas (particularly in India and Iraq) and at home, remaining in RAF service until 1940, also being used by the Air Forces of Australia, Canada, South Africa and India. It also formed the basis for the Westland Wallace which partly replaced the Wapiti in RAF use.

The Wapiti is named for the wapiti, also known as elk, one of the largest species of the deer family and one of the largest land mammals in North America and eastern Asia.

In 1927, the British Air Ministry issued Specification 26/27 for a replacement of the elderly Airco DH.9A, designed during the First World War which still equipped the Royal Air Force's General Purpose squadrons. To save time and money, the specification called for the use of a high proportion of DH.9A components, (as the RAF still held large stores of DH.9A spares), while it encouraged the use of an all-metal structure.[2] A large number of types were tendered to meet this requirement from most of the major British aircraft manufacturers, including Westland, who submitted the design that later became known as the Wapiti. Westland had an advantage in that it had carried out the detailed design work for the DH.9A, and was already a major contractor for the DH.9A.

The Wapiti was a conventional single-engined equal-span two-bay biplane with a slight wing stagger. It had tandem open cockpits and a fixed main undercarriage plus a tailskid. The forward fuselage was of metal tube structure with aluminium-and-fabric covering, while the rear fuselage was of fabric-covered wooden construction. The wings and tail were standard wooden DH.9A components, although later models replaced the wooden parts with an all-metal structure. The Wapiti was powered by a single Bristol Jupiter radial engine, and its crew of two were armed with a forward-firing Vickers machine gun and a Lewis gun for the observer, while it could carry up to 580 lb (264 kg) of bombs under the wings and fuselage. It was also fitted with radio and photographic cameras, and like the DH.9A before it, could carry a spare wheel for operations in adverse terrain.

The prototype first flew on 7 March 1927. Initial tests showed poor control, and the prototype was modified with a much larger tail and horn-balanced ailerons, solving these problems. (It was later discovered that a 2-foot (0.61 m) fuselage section had been omitted from the prototype – as handling was now acceptable, it was not reinstated.) The Wapiti performed well during RAF trials, while using significant amounts of DH.9A components, and was declared the winner of the competition, an initial contract for 25 aircraft being placed in October 1927.

After initial production, the wooden fuselage, tail and wings were replaced by metal structures in the Wapiti II and IIA, and the original long fuselage was eventually reinstated in the Wapiti V and later versions. In 1930, Westland produced an updated version of the Wapiti, the Wapiti VII, which differed so much that it was renamed the Westland Wallace.

Royal Australian Air Force – 44 Wapitis were in service from 1929 to 1944.
No. 1 Squadron RAAF
No. 3 Squadron RAAF
No. 1 Flying Training School RAAF
Central Flying School RAAF

For operational history and 11 variants, click here.

The Westland Welkin was a British twin-engine heavy fighter from the Westland Aircraft Company, designed to fight at extremely high altitudes, in the stratosphere; the word welkin meaning "the vault of heaven" or the upper atmosphere. First conceived in 1940, the plane was built in response to the arrival of modified Junkers Ju 86P bombers flying reconnaissance missions, which suggested the Luftwaffe might attempt to re-open the bombing of England from high altitude. Construction was from 1942 to 1943. The threat never materialised; consequently, Westland produced only a small number of Welkins and few of these flew.

Westland put forward their P.14, essentially an adaptation of Westland's Whirlwind fighter layout (and a more experimental twin, the P.13) to meet Air Ministry Specification F.4 of 1940 for a high altitude fighter. The most obvious feature was the enormous high aspect ratio wing, with a span on the production aircraft of 70 feet (21 m). The compact but troublesome Rolls-Royce Peregrine engines of the Whirlwind were replaced by the more powerful two-stage Rolls-Royce Merlin Mk.76/77. The most significant feature was a pressurised cockpit, which took the majority of effort in the design. After extensive development a new cockpit was developed that was built out of heavy-gauge duraluminium bolted directly to the front of the main spar. The cockpit hood used an internal layer of thick perspex to hold the pressure, and an outer thin layer to form a smooth line. Heated air was blown between the two to keep the canopy clear of frost.

In January 1941, the Ministry of Aircraft Production authorised the building of two P.14 prototypes DG558 & DG562. The F.4/40 specification was revised into F.7/41 that year. The Welkin design was now in competition with the Vickers Type 432 with Merlin 61 engines.

The pressurisation system was driven by a Rotol supercharger attached to the left-hand engine (this was the difference between the Merlin 76 and 77), providing a constant pressure of 3.5 psi (24 kPa) over the exterior pressure. This resulted in an apparent cabin altitude of 24,000 feet (7,300 m) when the aircraft was operating at its design altitude of 45,000 ft (14,000 m). This cabin altitude was still too high for normal breathing, so the pilot had to wear an oxygen mask during flight. A rubber gasket filled with the pressurized air sealed the canopy when the system was turned on, and a valve ensured the pressure was controlled automatically. Moreover, the pilot also had to wear a high altitude suit as he might have been required to bail out at altitude.

The Welkin required a sophisticated electrical system. This was to minimise the number of seals and points of entry in the cockpit for the controls and instrumentation. It took an electrician experienced in the features of the Welkin four hours to undertake a pre-flight check of this system. The wings were so large that the high lift Fowler flaps of the Whirlwind were not needed, and were replaced by a simple split flap. The extra wing area also required more stability, so the tail was lengthened to provide a longer moment arm. The armament − four Hispano 20 mm cannon − was the same as the Whirlwind's, but the Welkin carried the guns in a tray in its belly, which facilitated loading. In that position, muzzle flash was also less likely to dazzle the pilot.

The Welkin was seriously handicapped by compressibility problems caused by its long, high aspect-ratio wing which needed to be thick at the root (thickness-to-chord ratio of about 19%) for strength reasons. Compressibility caused the flight envelope (flyable speed range) between high-incidence stall and shock-stall to become very small at high altitudes – any decrease in airspeed causing a "normal" stall, any increase causing a shock-stall due to the aircraft's limiting critical Mach number. This reduction of the speed envelope is a problem common to all subsonic high-altitude designs and also occurred with the later Lockheed U-2. When W.E.W. Petter came to design his next high-altitude aircraft, the English Electric Canberra jet bomber, the required wing area was distinguished by noticeably short wings, with thickness-to-chord ratio (t/c) at the root of 12%, a t/c ratio which delays compressibility effects to an aircraft speed of about Mach 0.85.

Information on the Welkin was only released at the end of the war.

A two-seat radar-equipped night fighter version known as the Welkin NF.Mk.II for specification F.9/43 was developed but only one was eventually produced as the variant was not ordered into production.

By the time the Welkin Mk.I was complete and in production, it was apparent that the Luftwaffe was no longer conducting high altitude missions, due largely to successful interceptions by specially modified Supermarine Spitfires. Only 77 complete Welkins were produced, plus a further 26 as engine-less airframes.[10] Although two Welkins served with the Fighter Interception Unit based at RAF Wittering from May to November 1944, where they were used to gain experience and formulate tactics for high altitude fighter operations, the Welkin was never used operationally by the RAF.

Variants

P.14: Two prototypes built to meet Air Ministry Specification F.7/41.
Welkin Mk.I : Single-seat twin-engine high altitude fighter aircraft, 75 built, further 26 aircraft were completed without engines.
 Welkin Mk.II : Two-seat night fighter prototype, one converted from Mark I.

The Westland Whirlwind was a British twin-engined fighter developed by Westland Aircraft. A contemporary of the Supermarine Spitfire and Hawker Hurricane, it was the first single-seat, twin-engined, cannon-armed fighter of the Royal Air Force.

When it first flew in 1938, the Whirlwind was one of the fastest combat aircraft in the world and with four 20 mm Hispano-Suiza HS.404 autocannon in its nose, the most heavily armed. Protracted development problems with its Rolls-Royce Peregrine engines delayed the project and only 114 Whirlwinds were built. During the Second World War, only three RAF squadrons were equipped with the aircraft and, despite its success as a fighter and ground attack aircraft, it was withdrawn from service in 1943.

By the mid-1930s, aircraft designers around the world perceived that increased attack speeds were imposing shorter firing times on fighter pilots. This implied less ammunition hitting the target and ensuring destruction. Instead of two rifle-calibre machine guns, six or eight were required; studies had shown that eight machine guns could deliver 256 rounds per second. The eight machine guns installed in the Hurricane fired rifle-calibre rounds, which did not deliver enough damage to quickly knock out an opponent, and were dispersed at ranges other than that at which they were harmonised. Cannon, such as the French 20 mm Hispano-Suiza HS.404, which could fire explosive ammunition, offered more firepower and attention turned to aircraft designs which could carry four cannon. While the most agile fighter aircraft were generally small and light, their meagre fuel capacity limited their range and tended to restrict them to defensive and interception roles. The larger airframes and bigger fuel loads of twin-engined designs were favoured for long-range, offensive roles.

The first British specification for a high-performance machine-gun monoplane was Air Ministry specification F.5/34 for a radial-engined fighter for use in the tropics which led to four aircraft designs but the aircraft produced were overtaken by the development of the new Hawker and Supermarine fighters. The RAF Air Staff thought that an experimental aircraft armed with the 20 mm cannon was needed urgently and specification F.37/35 was issued to British aircraft companies in 1935. The specification called for a single-seat day and night fighter armed with four cannon. The top speed had to be at least 40 mph (64 km/h) greater than that of contemporary bombers – at least 330 mph (530 km/h) at 15,000 ft (4,600 m).

Eight aircraft designs from five companies were submitted in response to the specification. Boulton Paul offered the P.88A and P.88B (two related single engine designs differing in engine: Bristol Hercules radial or Rolls-Royce Vulture in-line respectively), Bristol the single-engined Type 153 with cannon in wings and the twin-engined Type 153A with cannon in nose. Hawker offered a variant of the Hurricane, the Supermarine Type 312 was a variant of Spitfire and the Supermarine Type 313 a twin-engined (Rolls-Royce Goshawk or Hispano 12Y) design with four guns in the nose and potentially a further two firing through the propeller hubs if the 12T was used, the Westland P.9 had two Rolls-Royce Kestrel K.26 engines and a twin tail.

When the designs were considered in May 1936, there was concern that on the one hand a two engine design would be less manoeuvrable than a single-engined design and on the other that uneven recoil from cannon set in the wings would give less accurate fire. The conference favoured two engines with the cannon set in the nose and recommended the Supermarine 313. Although Supermarine's efforts were favoured due to their success with fast aircraft and the promise of the Spitfire which was undergoing trials, neither they nor Hawker were in a position to deliver a modified version of their single-engined designs quickly enough - over two years for Supermarine.

Westland, which had less work and was further advanced in their project, was chosen along with the P.88 and the Type 313 for construction. A contract for two P.9s was placed in February 1937 which were expected to be flying in mid-1938. The P.88s were ordered in December along with a Supermarine design to F37/35 but both were cancelled in January.

The Westland design team, under the new leadership of W. E. W. "Teddy" Petter designed an aircraft that employed state-of-the-art technology. The monocoque fuselage was tubular, with a T-tail at the end, although as originally conceived, the design featured a twin tail, which was discarded when large Fowler flaps were added that caused large areas of turbulence over the tail unit. By the employment of the T-tail, the elevator was moved up out of the way of the disturbed airflow caused when the flaps were down. Handley Page slats were fitted to the outer wings and to the leading edge of the radiator openings; these were interconnected by duraluminium torque tubes. In June 1941, the slats were wired shut on the recommendation of the Chief Investigator of the Accident Investigation Branch, after two Whirlwinds crashed when the outer slats failed during vigorous manoeuvres; tests by the Aeroplane and Armament Experimental Establishment (A&AEE) confirmed that the Whirlwind's take-off and landing was largely unaffected with the slats locked shut, while the flight characteristics improved under the conditions in which the slats normally deployed.

The engines were developments of the Rolls-Royce Kestrel K.26, later renamed Peregrine. The first prototype, L6844, used long exhaust ducts that were channelled through the wings and fuel tanks, exiting at the wing's trailing edge. This configuration was quickly changed to more conventional, external exhausts after Westland's chief test pilot Harald Penrose nearly lost control when an exhaust duct broke and heat-fractured an aileron control rod. The engines were cooled by ducted radiators, which were set into the leading edges of the wing centre-sections to reduce drag. The airframe was built mainly of stressed-skin duralumin, with the exception of the rear-fuselage, which used a magnesium alloy stressed skin. With the pilot sitting high under one of the world's first full bubble canopies and the low and forward location of the wing, all round visibility was good (except for directly over the nose). Four 20 mm cannon were mounted in the nose; the 600 lb/minute fire rate made it the most heavily armed fighter aircraft of its era.

The clustering of the weapons also meant that there were no convergence problems as with wing-mounted guns. Hopes were so high for the design that it remained top secret for much of its development, although it had already been mentioned in the French press.

Many pilots who flew the Whirlwind praised its performance. Sergeant G. L. Buckwell of 263 Squadron, who was shot down in a Whirlwind over Cherbourg, later commented that the Whirlwind was "great to fly – we were a privileged few... In retrospect the lesson of the Whirlwind is clear... A radical aircraft requires either prolonged development or widespread service to exploit its concept and eliminate its weaknesses. Too often in World War II, such aircraft suffered accelerated development or limited service, with the result that teething difficulties came to be regarded as permanent limitations". Another 263 Squadron pilot said "It was regarded with absolute confidence and affection". By comparison the test pilot Eric Brown described the aircraft as "under-powered" and "a great disappointment".

For more deetails about development, operational history and variants, click here.

The Westland Whirlwind helicopter was a British licence-built version of the U.S. Sikorsky S-55/H-19 Chickasaw. It primarily served with the Royal Navy's Fleet Air Arm in anti-submarine and search and rescue roles.

In 1950, Westland Aircraft, already building the American Sikorsky S-51 under licence as the Westland Dragonfly, purchased the rights to manufacture and sell Sikorsky's larger Sikorsky S-55 helicopter. While a Sikorsky-built pattern aircraft was flown by Westland in June 1951, converting the design to meet British standards (including the provision of a revised main-rotor gearbox), was time-consuming, and the first prototype British aircraft, registered G-AMJT, powered by the 600 hp Pratt & Whitney R-1340-40 Wasp did not fly until August 1953. This was followed by ten Whirlwind HAR.1s, which entered service shortly afterwards. They served in non-combat roles, including search and rescue and communications functions. The HAR.3 had a larger 700 hp Wright R-1300-3 Cyclone 7 engine.

The performance of early versions was limited by the power of the American Wasp or Cyclone engines, and in 1955, the HAR.5, powered by an uprated engine, the Alvis Leonides Major, flew for the first time. This was followed by the similarly powered HAS.7, which became the first British helicopter designed for anti-submarine warfare in the front-line when it entered service in 1957. It could either be equipped with a dipping Sonar for submarine detection or carry a torpedo, but could not carry both simultaneously, so sonar equipped "Hunters" were used to direct torpedo armed "Killers". The HAS.7 was powered by a 750 hp (560 kW) Alvis Leonides Major 755/1 radial engine. It had a hovering ceiling at 9,400 ft (2,900 m) and a range of 334 miles at 86 mph.

In 1960 Westland introduced a Whirlwind powered by the 1,000 hp Bristol Siddeley Gnome turboshaft, the greater power giving much improved performance over the earlier piston-engined variants; helicopters receiving this modification were redesignated as the HAR.9. The Gnome featured an early computer controlled fuel system that removed variations in engine power and made for much easier handling by the pilot.

More than 400 Whirlwinds were built, of which nearly 100 were exported to foreign customers.

848 Naval Air Squadron of the Royal Navy's Fleet Air Arm was the first squadron to receive HAR.1s, which replaced Sikorsky-built HAR.21 versions of the Whirlwind, for utility and search-and-rescue service from July 1954. After entering service with the Royal Navy, the Whirlwind also entered service with the Royal Air Force and French Navy, which received 37 Whirlwind HAR.2 between 1954 and 1957.

The Royal Air Force Search and Rescue Force used Whirlwinds painted in overall yellow for rescuing people in distress around the coast of the United Kingdom. Westland Wessex, and eventually Westland Sea King, helicopters later supplemented and eventually replaced Whirlwinds in this role.

For details of the 19 variants, click here.

The Westland Wyvern was a British single-seat carrier-based multi-role strike aircraft built by Westland Aircraft that served in the 1950s, seeing active service in the 1956 Suez Crisis. Production Wyverns were powered by a turboprop engine driving large and distinctive contra-rotating propellers, and could carry aerial torpedoes.

The Wyvern began as a Westland project for a naval strike fighter, with the engine located behind the pilot, driving a propeller in the nose via a long shaft that passed under the cockpit floor, similar to the Bell P-39. This enabled the pilot to be located in a position that conferred the best possible visibility over the nose for carrier operations. Official interest resulted in Air Ministry Specification N.11/44 for a long-range naval fighter using the 24-cylinder H-block Rolls-Royce Eagle 22 piston engine (unrelated to the First World War-era engine of the same name) being issued to cover Westland's design. The specification also called for an airframe design that would be able to take a turboprop engine when a suitable unit was available. There was a parallel specification for the Royal Air Force, F.13/44, for which Hawker submitted the competing P.1027, a development of the Tempest. The RAF variant was cancelled, when in 1945 it was decided that all future fighter aircraft would be jet-powered.

The original design soon matured into the more conventional Westland W.34, with the 3,500 hp (2,610 kW) Eagle engine in the nose driving large contra-rotating propellers and the pilot sitting high in a humped fuselage to improve visibility. The design was otherwise orthodox, with a low wing, tailwheel undercarriage and double-folding wings fitted with both Youngman flaps on the inner wing section and conventional flaps on the outer section. The W.34 was to be armed with four Hispano 20 mm cannon in the wings and have the ability to carry a torpedo under the fuselage or a selection of bombs and rockets under the wings.

The prototype W.34; the Wyvern TF.1, first flew at Boscombe Down on 16 December 1946[a] with Westland's test pilot Harald Penrose at the controls. This aircraft was lost on 15 October 1947 when the propeller bearings failed in flight. Westland's assistant test pilot Sqn. Ldr. Peter Garner was killed attempting to make an emergency landing. From prototype number three onwards, the aircraft were navalised and carried their intended armament.

At around this time, the Eagle engine was cancelled and it was found that there were insufficient pre-production engines available to complete all the prototype and pre-production aircraft. Specification N.12/45 was therefore issued for the Wyvern TF.2, to be powered by a turboprop engine: either the Rolls-Royce Clyde or the Armstrong Siddeley Python. A single Clyde-powered prototype was ordered along with two with Pythons. A Clyde-powered TF.2 first flew on 18 January 1949. Both the piston-powered and turboprop versions shared many common components including wing and tail units, and essentially the same basic cockpit structure. The flight was cut short to only three minutes when shortly after takeoff, the cockpit filled with smoke from a fuel leak onto the exhaust ducting. Clyde development was subsequently cancelled by Rolls-Royce after only 50 hours of flight time for the TF.2, and the aircraft was delivered to Napier & Son to be fitted with the Nomad turbo-compound engine. The latter engine never materialised, however and this aircraft was used for crash barrier trials.

The first Python-powered TF.2 flew on 22 March 1949 and this aircraft introduced the ejection seat to the Wyvern. Twenty TF.2s were completed to the Python design although after three years of testing what was then a revolutionary aircraft design, a myriad of detailed aerodynamic changes resulted. The Python engine responded poorly to minor throttle adjustments, so control was exercised by running the engine at a constant speed and varying the pitch of the propellers. The aircraft was declared ready for service in 1952, but never reached an operational squadron.

The definitive Wyvern model was the TF.4, later S.4. Initially, 50 S.4s were ordered and were joined by the last 7 TF.2s, which were altered while still under construction. S.4s reached limited shore-based front line service in May 1953 with 813 Naval Air Squadron at RNAS Ford, replacing the somewhat similar (and equally troubled) Blackburn Firebrand. Several second-line squadrons also received Wyverns around this time.

Total production was 127 airframes with 124 aircraft completed, as the last three Eagle piston-engined airframes, VR138, -139, and -140, were never completed.

For details of operational history, click here.

Variants

W.34 Wyvern
Six prototypes ordered in August 1944, with the first aircraft flown 12 December 1946. Powered by the Rolls-Royce Eagle Mk 22 H-block, piston engine.
W.34 Wyvern TF.1
Pre-production aircraft ordered in June 1946, with only seven built of 20 contracted due to the cancellation of the Eagle powerplant.
W.35 Wyvern TF.2
The original production version, powered by the Armstrong Siddeley Python turboprop in replacement of the discontinued Eagle piston powerplant seen on the W.34 prototypes. Three prototypes were ordered in February 1946 with a production contract for 20 aircraft issued in September 1947. Only nine production aircraft were built, and the remaining eleven were completed as S.4s.
W.38 Wyvern T.3
Two-seat conversion trainer. One prototype serialed VZ739 was ordered in September 1948 and first flown in February 1950.
W.35 Wyvern TF.4
The definitive version. 50 were ordered in October 1948, 13 in December 1950, 13 in January 1951 and a final 11 in February 1951. A total of 98 built (including 11 that had started as TF.2s). The model was later redesignated as the S.4.