TURBI

Take three Turbis…

Igor Best-Devereux, whose father Harold was an early Chairman and enthusiastic advocate of the Popular Flying Association, gives some historical context to the three Druine Turbis built in the late 1950s…

Photos from the Harold Best-Devereux Collection unless otherwise noted.

There have been some aircraft that were only produced in small numbers, but nonetheless played an important role in the development of the light aircraft movement. Such was the destiny of the Druine Turbi. By 1954 after several years of pushing by the Ultra Light Aircraft Association / Popular Flying Association founders, airworthiness investigations for ultra-light aircraft had been delegated to the organisation. There was finally the opportunity to build new, economical Above The TK Flying Group’s G-AOTK, built by de Havilland apprentices. aircraft to support the flying groups that had been relying on surplus Tiger Moths, Magisters and other types. For several years the PFA had been evaluating potential aircraft, and after much analysis and debate, including developing the specification for a two-seat trainer, took the initiative in obtaining plans from Avions Roger Druine in France. By 1955 examples of both the single-seat Turbulent, viewed as a good fit for the amateur builder, and the two-seat Turbi, viewed more as a club or group aircraft, were under construction.

PFA Turbi: G-APFA

Seeking to raise awareness of the PFA, the Association entered into an agreement with Associated-Rediffusion to build a Turbi as part of the new current affairs television programme This Week. When built, ownership of the Turbi would rest with Ulair Ltd., the commercial entity of the PFA, with the intention that the aircraft was to be a promotional tool for the organisation. From laying out the early strips of spruce through to the first flight, the This Week Turbi captured attention among a national TV audience that, by the mid-1950s, was many millions. Under the agreement, the build in 1956/57 was outsourced to John Britten and Desmond Norman, and their Britten-Norman company in the Isle of White. Britten-Norman had already been active in the ULAA/ PFA, building the single seat BN-1F design, a single-seat parasol wing ultralight powered by a 37hp JAP J99 twin, that first flew in May 1951. My late father, Harold Best-Devereux (HB-D), applied a little friendly influence at the Air Registration Board, where he worked, to obtain the out of sequence G-APFA registration and he often flew his Auster from Elstree to Bembridge at weekends to help with the construction and undertake the necessary engineering inspections for the Turbi’s Permit to Fly. Several PFA members added their labour to assist the Britten-Norman team as there was intense pressure to complete the project within the contracted timeframe, sometimes creating challenges in coordination. The author’s mother recounted the ‘despair’ experienced when, after a long weekend spent forming and gluing the plywood leading edge and then departing for Elstree, another helper arrived and removed the clamps before the glue was dry! As an additional effort to promote a British light aviation revival, the Turbi was fitted with a four-cylinder Coventry Victor ‘Flying Neptune’ engine. The engine was provided for the project by Major Bill Weaver of the Coventry Victor company, which had been an active supporter of the ULAA from its earliest days. Ostensibly Left Harold Best-Devereux flying G-APFA from Bembridge 19 May, 1957.

Below HB-D with the improved Turbi Sport – Elstree 1958.

of 55hp, the engine had been tested at Southend on Cub G-AIYX in 1955, unfortunately without much success, which was not a good omen for it powering the Turbi. With previous experience flying the prototype Turbi (F-WFUU) at Toussous in January 1955, HB-D first flew APFA on 19 May 1957 at Bembridge – two flights being made that day – the Neptune engine proving rather inadequate for the task. Additional test flights were carried out, and in September the aircraft was flown to Sywell to be a centrepiece at the September 1957 National Air Rally of the PFA, held on 14th and 15th. The Turbi was resplendent in its blue and yellow scheme with ‘Coventry Victor Engines’ advertised on the cowling. Following the Rally, APFA went on to be displayed at the Earls Court Olympia ‘Do it Yourself’ exhibition. The event captured another wide audience as well as being reported in the October 1957 Aeroplane magazine. HB-D flew the aircraft back to Elstree on 5 March 1958 and, over the next few months, fitted a ‘coupe’ canopy, somewhat reminiscent of a Chipmunk, and swapped the heavy and underpowered engine for a much better suited 65hp Continental. This became the Druine D.54 Turbi Sport. Roger Druine’s name was painted on the fuselage to honour the designer who had so tragically died just months before. Finally, with enough power for two, the author’s mother, Lenka, was the Turbi Sport’s first passenger.

Left G-AOTK under construction at Hatfield Technical College, 1957. Photo: TK Flying Group.

Below The 50th anniversary reunion of TK Flying group members held at Rush Green in Hertfordshire. Lenka Best-Devereux and Sonja Fillingham at centre. Photo: TK Flying Group.

TK Turbi: G-AOTK

Even before the decision was taken to build the PFA Turbi, in 1954 two de Havilland apprentices, Neil Harrison and Tim Longley, met HB-D at Elstree and learned about the Druine types. Captivated by the idea of building a group aircraft they approached the de Havilland technical school with the idea, but were rebuffed. Enthusiasm prevailed however, and in December 1954 they formed the TK Flying Group. The Hatfield Technical College (now the University of Hertfordshire) gave them workshop space and the first longeron was laid out on 26 March 1955 by the then Chairman of the PFA, and Managing Director of the Bristol Aeroplane Company, Peter Masefield. Flight magazine, 1 April 1955, reported that the ceremony marked the start of the first amateur-built aircraft of post-war design in Britain. An emphasis reflecting the opinion expressed by some in the light aircraft movement that it was time to move on from pre-war designs. After the company’s initial rejection, de Havilland got behind the build, allowing their technical school to help fabricate parts and their engine division to overhaul the pre-war Walter Mikron II engine. The initial estimated cost of the project was £300, but as so often happens, the costs escalated and finally finished at £450. Fortunately, some financial assistance came from the Kemsley Trust, created in 1947 to support the building and flying of light aircraft. The first flight of Turbi G-AOTK was at Hatfield Aerodrome on Saturday 9 August 1958, with de Havilland chief production test pilot, Pat Fillingham, at the controls. The little Mikron engine was a gem and unlike the Coventry Victor-powered APFA, AOTK proved to have a rather light nose, so was initially flown solo from the front cockpit. Neil Harrison flew the Turbi that same day and the following week, with only 35 hours of solo time in his logbook, he set off for the RSA Rally at Saintes les Gondes, near Bordeaux – held on 15-17 August. It had been hoped to fly two Turbi’s to Saintes, HB-D wanting to reciprocate the RSA’s support of the 1957 PFA Rally when French participation included Jean Barritault in his Minicab, and RSA President George Beraud and his brother who both arrived via Jodels. The rework of Turbi APFA was almost completed in time for a formation

flight to Saintes, but it wasn’t to be. Instead, together with Maurice Imray, HB-D accompanied the TK Turbi in his Auster J4, G-AIJM. They were joined for the Channel crossing by Norman Jones in the first Rollason Turbulent, G-APBZ. On arrival at Saintes, Neil became the first pilot to land at the annual RSA Rally in a British amateur built aircraft, and the Turbi won third prize at the event. Just as with the first Turbi, the TK Group aircraft quickly played a part in promoting amateur building. Between July 8 and 11, 1959, Pat Fillingham flew the Turbi in the National Air Races. Next the group participated in the Daily Mail London to Paris Air Race, held to commemorate the 50th anniversary of Louis Bleriot’s first cross-Channel flight, the team using the Turbi and two cars built by de Havilland apprentices. Derek Mott was rushed from Marble Arch to the Arc de Triomphe in less than 4hr 30min each way, winning the team a £100 consolation prize for ingenuity.

Rutherglen Turbi - G-APBO

The third Turbi to be completed was G-APBO, built by the Rutherglen flying group, PFA Group 39, under the leadership of Glasgow doctor Frank Roche. This group had fewer resources than Britten-Norman or the TK Group, but the February 1957 PFA Bulletin reported that the Turbi was well underway in the loft of a Glasgow joinery company. In the Bulletin , HB-D referred jokingly to ‘escaping with his life when he visited to inspect the main spars and found them unsatisfactory’. But lessons were learned, and the project proceeded at a pace. Requiring space to assemble the aircraft, the group even built their own hangar and prepared a landing strip at South Carnduff Farm, near Strathaven. The first flight of the Mikron powered ‘PBO was made by HB-D on 21 July 1960, there being three flights that day. Not to be upstaged by its forerunners, the next day the Turbi flew again for the BBC’s cameras.

Put to work

After each of their starring roles, the Turbis became active club work horses, G-AOTK staying at Hatfield until the airfield was finally closed in the 1990s. G-APFA started work in 1962 with the Wolverhampton Ultra Light Flying Group at Halfpenny Green and G-APBO provided many hours of club flying for the Rutherglen group.

Above G-APBO complete and ready to take to the skies, 1960.

Lasting impact

Over 60 years, the impact of the Turbis was two-fold. In the context of the late 1950s they embodied the optimism of the PFA at the time, optimism expressed by HB-D when he wrote in Popular Flying in November 1958, accepting the role of Chairman of the PFA executive committee. Thanking Edward Mole, Alfred Weyl, the Imray brothers, Ron Clegg and Rosemary Lindsay-Neale for their efforts to promote ‘flying for fun’ – a term he noted ‘coined by Maurice Imray and explaining in the proverbial nutshell our aim in life’. Maybe more enduring, each Turbi, in its own unique way, acted as a long-lasting platform for education, pilot training, promotion of light aviation in the UK and the joy of flight and the community of group flying. The seeds planted by the reliable little two seaters grew and endured over many years, perhaps exemplified most of all by the TK Turbi group, with some of the group pictured here at the 50th anniversary of the TK Turbi’s first flight. Today, all three Turbis remain in existence. APFA was in storage for many years but was acquired by a new owner in early 2018 and is believed to be in rebuild. APBO has been owned by retired vet Rupert Hibberd for nearly 30 years, and the TK Turbi group still owns AOTK.

Why weren’t there more Turbis?

A question often asked is, why were there so few Turbis? It proved to be straightforward, sturdy and reliable, designed and built along conventional lines and with good performance and honest handling. Perhaps the limited availability of suitable engines at the time, the open cockpits and tandem seating may have all played a part in limiting the attraction. Realistically the Turbi was also a large project for an individual builder at the time, with many parts to fabricate. Each of the three aircraft discussed were group efforts, involving many hands to complete. In contrast, most of the side-by-side Condors, Jodels and Emeraudes, that became so popular for clubs and touring, were built by commercial concerns. ■