The Rotodyne was a compound aircraft with wings, tractor engines and a tip-driven rotor system. Unfortunately, it was use of the tip jets at and near the airport that was the problem. The Rotodyne put out a painful 106 decibels of shrieking noise. Much work was done on silencers, but it was never reduced to the 96 decibels that the authorities demanded. Budgetary problems of the time saw the RAF and British Army withdraw their interest and the Rotodyne became a wholly civil project. Fairey talked up expressions of interest from BEA in the UK, New York Airways and the US Army, but the crucial launch order never came. British government policy to rationalize the industry saw the end of the Rotodyne and Fairey as an airframe maker in 1962.

Jim Winchester "The World's Worst Aircraft", 2005

The concept of a vertical take-off airliner has captured the imagination of designers and airlines virtually since passengers were first taken aloft in a balloon, almost exactly 200 years ago.

With the concept of the convertible helicopter proved on a small scale with the Jet Gyrodyne, the proposal put forward by Dr. J.A.J. Bennett and Captain A.G. Forsyth in 1947 for a large compound helicopter looked viable, and various designs were considered. In December 1951 British European Airways issued a specification for a 30-40 seat passenger aircraft for short/ medium-haul routes and Fairey submitted a proposal along with other manufacturers; the layout corresponded roughly to Fairey's ideas and in 1953 the company received a Ministry of Supply research contract for a prototype.

Test rigs were established at White Waltham and Boscombe Down, where an elaborate installation eventually comprised the rotor assembly, both power-plants, stub wings, etc., with all controls in a hut where the aircraft's nose would have been. Extensive testing was carried out while the prototype was under construction, and the Fairey Rotodyne made its first flight as a helicopter on 6 November 1957; it was not until April 1958 that the first transition to normal flight was made.

Basic layout of the Rotodyne was a square-section fuselage with untapered stub wings on which were mounted two Eland turboprops for forward propulsion. The main wheels of the tricycle landing gear retracted forwards into the nacelles, and the nosewheel forwards below the cockpit. Twin fins and rudders, later joined by a central fin, were mounted on an untapered tailplane set on top of the rear fuselage. A large four-bladed rotor for vertical take-off and landing was driven by tip jets which received compressed air from the Eland engines via a compressor; each engine fed air to two opposing rotor blades to ensure that, in the event of an engine failure, there would be enough pressure in the remaining engine to keep two tip jets burning.

Following its success in establishing a speed record with the Gyrodyne, Fairey decided that the Rotodyne's performance would enable it to repeat the feat, and on 5 January 1959 it set a record in the convertiplane class with an average speed of 307.2km/h over a 100km closed circuit; this record stood until October 1961, when the Russians beat it with the Kamov Ka-22.

The Rotodyne's future looked bright; during 1958 the Kaman Aircraft Corporation secured a licensing agreement for sales and service in the USA with a possibility of manufacture there. Okanagan Helicopters of Vancouver was interested in three and Japan Air Lines was considering the type for domestic routes. However, the biggest potential customer was New York Airways, which joined with Kaman in a letter of intent for five, plus options on 10, for delivery in 1964. These were to be the larger 54/65-seat versions with Rolls-Royce Tynes.

Fairey needed up to GBP 10 million to develop this version and was offered 50% of this by the government if BEA would place a firm order. The government contribution was to be a loan, repayable by a sales levy. In 1960 Fairey merged with Westland and although initially the Rotodyne project looked secure, it was not. In April 1960 Okanagan cancelled its order because of the long delivery dates, and five months later New York Airways expressed concern over the delay in production plans. Westland was then involved in taking over Bristol's helicopter programme as well as with other work in hand. This, together with the ever-increasing weight of the Rotodyne, which reached a stage where the Eland could no longer be developed and the Tyne could not be afforded, led to withdrawal of government support, and the project was cancelled in February 1962.

D.Donald "The Complete Encyclopedia of World Aircraft", 1997

The initial work accomplished by Fairey with the unloaded-rotor concept was accomplished in the early 1950s with an earlier program, the Gyrodyne, which was powered by a single reciprocating engine. The main emphasis of this development was a commercial application with the design of an intercity rotorcraft.

The emphasis behind the development was the belief that this concept could overcome a number of the inadequacies of standard helicopters, i.e. inadequate payload, insufficient range, mechanical complexity, excessive vibration, and the inability to remain aloft in case of powerplant failure.

With the Rotodyne concept, a pair of engines each drove a single propeller which provided the propulsion for horizontal flight. The engines also supplied air to a compressor that supplied air to jets that were located on the rotor tips, the power from which provided the hovering capability of the craft. This energy provided aerodynamic lift by whirling the overhead rotor, exactly the same concept as with a standard helicopter.

Once the desired altitude was acquired through this process, the total power of the engines was diverted to driving the propellers. Also, the tip jet operation was ceased and the lift for horizontal flight was obtained by the propeller and the stub wings upon which the engines were mounted. A feature of the design was that adequate single-engine performance was provided following an engine failure at any flight speed.

Transition from vertical-to-horizontal flight, with the rotor autogyrating, was accomplished on April 10, 1958.

The pair of Napier powerplants provided an impressive total of 7000 horsepower with a gross weight of 17500kg. With a payload of 4500kg, the plane was capable of a range exceeding 650km at up to 270km/h. Impressive performance indeed! It's easy to understand why Fairey was so confident that it had a real winner with the Rotodyne.

The technique, though, of the engines serving a dual purpose was the same as the Gyrodyne system, each driving a propeller and providing the compressed air for the pressure-fed wingtip jets. To provide an idea of the size of this machine, vision the fact that the rotor was 27.4m in diameter. For safety aspects, two opposing blades were powered by each engine in case of engine failure. An onboard hydraulic system provided for cyclic pitch control.

The Rotodyne was extremely large, with a cabin volume of 93m³ cubic feet. The logistical attributes of the machine were considerable with rear clam-shell doors allowing the loading of large motor vehicles. A forward-located door permitted simultaneous entry and exit of passengers, which would have allowed a quick turn-around in a commercial airline operation.

It was estimated that a passenger load of as many as 48 could have been carried by the Rotodyne. That passenger compartment was 14m long, 2.4m wide, and 1.8m in height.

Like other compound-type VTOL vehicles, had the Rotodyne been minus its trapezoidal rotor-mounting pylon, the vehicle would have looked much like a conventional aircraft. The rotor was mounted at a lofty 6.70m above the ground, providing an idea of the size of the Rotodyne.

The design sported a high wing and a twin-tail configuration. That tail design was interesting in that the lower tail surfaces were oriented straight down, while the upper surfaces were canted at about a 45 degree angle.

The speed capability of the Rotodyne of about 320km/h made it slower than traditional transports, but it could make up for that deficiency with the capability of landing on downtown heliports atop buildings and getting business people to their final destination much quicker. Another attractive aspect of the Rotodyne for this commercial application was the fact that it was projected to have a range of up to 640km at gross weight.

The Rotodyne was subjected to a vigorous flight test program of over 350 flights, more than half of them demonstrating 200 hover-to-vertical flight transitions.

The production Rotodyne was to be a somewhat larger vehicle with a rotor diameter of an amazing 27m with a gross weight of 30 tons. The propulsion systems would be changed to Rolls-Royce Tyne engines.

There was serious consideration for production of the craft, both domestically and in the United States. That possibility came to light in 1958 when a license agreement was reached between the Kaman Aircraft Corporation (USA) and Fairey. The agreement provided for the manufacture of the aircraft in the U.S. by Kaman.

S.Markman & B.Holder "Straight Up: A History of Vertical Flight", 2000

In the House of Commons on 16 July 1959 the then Minister of Transport and Civil Aviation said of the Rotodyne: 'The view of B.E.A. and my view is that it is a winner'; yet less than three years later this highly advanced aeroplane was abandoned because these same two authorities lacked the faith to give it continued support. This was a bad enough decision even then; less than six years later, the current British government's 'saving' of L10 million, by cancelling the Chinooks it had ordered only weeks before, reveals it to have been even more foolhardy. The same amount of money, spent on completing the Rotodyne's development in 1962, would have provided the R.A.F. much sooner with a vehicle having far better carrying power, performance and operating costs than the Chinook.

The Rotodyne story began with a much smaller aeroplane, the Fairey Gyrodyne prototype G-AIKF, which first flew on 7 December 1947. This had a 390kW Leonides piston engine driving a 15.74m 3-blade main rotor and a small tractor propeller in a fairing at the tip of its starboard stub wing. After setting a helicopter speed record of 200km/h in June 1948, the first Gyrodyne was destroyed in an accident during the following April; but a second similar machine (G-AJJP) was completed, and in 1954 this was converted into the Jet Gyrodyne XJ389 to test design features of the Rotodyne. The original 3-blade rotor was replaced by a 2-blade assembly and the shaft drive to the rotor was eliminated. Instead, Fairey-designed pressure jets were mounted at each blade tip, in which compressed air fed from the engine was ignited with kerosene to drive the rotor. Small pusher propellers were mounted at each of the wing-tips.

The Rotodyne prototype (XE521) was ordered by the Ministry of Supply in August 1953 and made its first vertical take-off on 6 November 1957. Early trials were carried out with the aircraft functioning purely as a helicopter, the first transition from a vertical take-off to forward flight being made on 10 April 1958. For this manoeuvre the entire power of the two Eland turbo-prop engines was transferred from the 4-blade rotor to the tractor propellers. On 5 January 1959 the Rotodyne set a closed circuit speed record of 307.22km/h, exceeding the previous record by 78.86km/h and the existing absolute record for helicopters by 46.67km/h. Later that year the wings were given ailerons and increased incidence, and the vertical tail surfaces were also revised. On 7 February 1960, XE521 resumed trials with an added central fin, shortened exhausts and a fully-faired rotor pylon.

The prototype had been built as a 40-seat aircraft with a crew of 3. When Westland acquired Fairey Aviation in 1960 it abandoned its own large helicopter, the Westminster, in favour of the Rotodyne, and with the help of L4 million government backing continued to develop an enlarged version to production standard. This became known as the Rotodyne Z (the prototype being restyled Rotodyne Y), and as envisaged at the time of its cancellation would have accommodated 57-75 passengers or 8165kg of freight in a 21.16m fuselage and cruised at 370km/h on the power of two 3915kW Rolls-Royce Tyne engines. Okanagan, the Canadian operator, had tentatively ordered one Rotodyne in 1958, and Indies Air of Puerto Rico signified its interest in the type in 1961. But the major potential customers were B.E.A. and New York Airways, which declared their intent to order six and five respect-lively, each with an option to increase its fleet later to twenty. The Rotodyne Z had been designed with an eye also on military orders, with a fuselage cross-section capable of admitting standard British Army vehicles - a feature which, incidentally, would have made it equally useful as a commercial car ferry. Late in 1960 Westland were invited to quote for building six Rotodynes for B.E.A. and twelve troop/vehicle transports for the R.A.F.; but when both airline and government declined either to order the aircraft or to contribute further towards its development Westland finally abandoned the project in February 1962 and the Rotodyne Z was never completed. Although lack of faith in the aircraft was the main cause of its demise, a contributory factor was the disproportionate publicity given to the noise made by the Rotodyne's tip-jets, which it was said would inhibit its use in city centres. In fact, well before the aircraft was abandoned this noise had been successfully decreased to less than that made by a London Underground train, which millions of people accept every day; and there was every indication that it would have been reduced even further.

K.Munson "Helicopters And Other Rotorcraft Since 1907", 1968

From the Jet Gyrodyne, Fairey developed the much more ambitious Rotodyne which flew for the first time on 6 November 1957. It was a large compound aircraft with a four-blade rotor more than 31m in diameter, driven by blade-tip jets fed with compressed air bled from two 3000shp Napier Eland turboprops mounted in nacelles on a 14.17m span wing. The same engines drove two four-blade propellers which gave a good cruise speed of approximately 300km/h, while the stocky fuselage had very good cubic capacity.

On 5 January 1959, the Rotodyne established a world speed record for rotary wing craft of 307km/h and its appearance aroused great interest among commercial operators. The RAF also considered ordering the type, but amalgamations within the British aeronautical industry at that time and problems with noise from the tip jets prevented full-scale production, and the Rotodyne project was abandoned in 1962.

G.Apostolo "The Illustrated Encyclopedia of Helicopters", 1984

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Technical data for Fairey "Rotodyne"

Engine: 2 x Napier Eland NE1.7 turboshaft, rated at 2088kW, main rotor diameter: 27.43m, wingspan: 14.17m, fuselage length: 17.88m, height: 6.76m, take-off weight: 14969kg, cruising speed: 298km/h, range: 724km