Most of us know something about the cars pictured in these photos but I thought it might be interesting to say something about the aircraft pictured here, the Bristol T188, as well as some other Bristol design projects. The pictures are not new but featured in an article in Octane in April 2012. However we thought you might like to see them again as they are great photos!
The first Bristol turbojet aircraft to be built and fly, the Type 188 was also the last true Bristol type to fly.
The Type 188 was an experimental twin engine aircraft designed for sustained flight in excess of twice the speed of sound for long enough to enable steady-state kinetic heating effects on the structure to be studied.
Stainless steel was chosen for the primary structural material to avoid the potential kinetic heating limits of aluminium alloy. However great difficulty arose in the supply of the steel material and in all means of attachment which had to be in compatible material. So new manufacturing methods and materials had to be developed.
The cockpit was also fitted with a refrigeration system although this was never used. Frontal area was minimised with a long slim fuselage and a very thin (4%) wing section was employed.
Originally Rolls-Royce Avon RA.24R engines were planned but later D.H. Gyron Junior DGJ.10 engines which had been specified for another, now discontinued project, became available and were substituted.
Initially six examples were ordered but later, three were cancelled as an economy measure. Finally, two prototypes (XF923 & XF926) and one static test airframe were finally ordered under contract and their construction and development continued alongside the Avro730 programme (a Mach 3 reconnaissance aircraft and strategic bomber that was being developed by Avro Aircraft for the RAF but cancelled in 1957).
After many delays, the first prototype (XF923) flew for the first time at Filton on 14th April 1962, with Bristol Chief Test Pilot Godfrey Auty at the controls. It landed at Boscombe Down 23 minutes later, from where it made a further 16 flights, before returning to Filton for its last two flights. It made its public debut when flying on four consecutive days at the SBAC Farnborough Air Show, in September 1962.
The second flying prototype, XF926, utilised XF293’s De Havilland Gyron Junior PS50 engines for its first flight on 26th April 1963, before the later Mach 2 engines were fitted. The whole of the flying programme for the second aircraft was conducted from Filton.
In all, 70 tests flights were carried out, the fastest being to 1,430 mph (purely coincidentally the equivalent of Mach 1.88), whilst the longest flight was just 48 minutes in duration.
Many problems occurred during flight testing with the engines having a worrying tendency to ‘flame out’ or surge at supersonic speeds. This was bad news for the pilot as the T188 was not a good glider! On one famous occasion due to a different fault, it had to land at the nearest airfield with a long runway and this was RAF Fairford. However Fairford was an American base at the time hosting B-52s at the height of the cold war. So the T188 was not a welcome visitor!
Although the aircraft was designed for speeds above 1,200 mph, its utility was limited because of its very restricted endurance at these speeds and the high fuel consumption of the engines. With typical flight times in the order of 25 minutes, and with the two aircraft combined only completing a total of 70 flights (not all flights were test flights), the project was abandoned in 1964 after the last flight on 12th January of that year.
Whilst some of the materials and construction knowledge gained through the Bristol 188 programme proved useful during the development stages of Concorde, a lot of the data gathered proved inconclusive for the advancement of Mach 2 and Mach 3 aircraft.
To quote the book written by a former colleague at Bristol who was instrumental in designing the Concorde intake system and who cut his teeth on the T188, “Was it coincidence that the contract for the Bristol Type 188 was terminated after reaching a Mach number of 1.88? It had served one significant purpose however – it showed us what not to do!”* or in other words, don’t build Concorde out of stainless steel!
The second prototype is preserved at the RAF Museum, Cosford (pictured above with the cars), the first having been scrapped after use as for target practice at Shoeburyness Ranges. This is a fate which befell many British experimental aircraft after their useful life had finished or they had been cancelled including the TSR2
The last aircraft to fly with a Bristol type number, the Bristol T221 was a modification of the Fairey Delta FD2 which had broken the World Air Speed Record on on 10 March 1956 raising it to 1,132 mph or Mach 1.73. At Bristol the first of two FD2’s to be built was fitted with a new ogee shaped wing similar in planform to that of Concorde. It first flew on 1 May 1964 with Godfrey Auty at the controls. It had a very successful test programme and delivered much useful data for the flying qualities of Concorde. Its flying career lasted until June 1973 and it can be seen in RNAS Yeovilton museum.
Later Bristol projects worth mentioning are the Type 198 and the Type 223. The 198 was an early design study for a supersonic transport which went through several configuration changes before becoming, in a brochure from 1961, an aircraft with a slender delta wing powered by 6 engines mounted in two groups of three below the wing (previous versions had shown the engines mounted together both above the wing and later below it!). It was designed to cruise at around Mach 2.2 and have transatlantic range. The basic structure was aluminium alloy (T188 lessons learned!) and the standard layout was for 136 economy passengers.
Much design work was put into the T198 but it was then decided that this aircraft was becoming too large and a completely new proposal, the T223 powered by just 4 engines, was examined as a basis for a cooperative aircraft project. Cruise speed was Mach 2.2 with 100 passengers and transatlantic range. This aircraft had many similarities to the final Concorde design, and it was selected as a basis for an SST design for the UK. Together with the Sud-Aviation Super-Caravelle it was then developed into the Anglo-French Concorde.
This is of necessity a very short summary of the Bristol projects leading up to Concorde, but I can thoroughly recommend the following books for the complete story. Much of the information contained here comes from my own personal knowledge and from these books and I acknowledge their help.
• In my opinion, the best book on the background to the design of Concorde which also includes the French contributions is “Building Concorde – From Drawing Board to Mach 2” by Tony Buttler and Jean-Christophe Carbonel, Crecy Publishing Ltd.,2018. This book also contains some information on the T188 and the T221.
• More information on the T188 can be found on the BAE Systems Heritage website
• A further book which contains a very personal account of a Concorde designer is “Concorde- a Designers Life – the Journey to Mach 2” by Ted Talbot, The History Press, 2013*.
Ted was instrumental in designing the highly complex Concorde intake system and cut his teeth on the T188. He also relates many stories of working with the French and of Concorde flight testing.
• If you want a very detailed description of the Concorde design I can recommend “Concorde – New Shape in the Sky” by Kenneth Owen, Jane’s, 1982. This book was later revised and published as “Concorde – story of a supersonic pioneer”, Science Museum, 2001.
• For a description of all the Bristol aircraft and projects, the go-to book is “Bristol Aircraft since 1910” by CH Barnes, Putnam, 1964.
On a personal note, I joined Bristol Aircraft in 1969 as a Student Apprentice and finished up working in the Filton Aerodynamics Office on the T221 and later the Concorde. I count myself very privileged to have worked alongside such fine engineers as Ted Talbot and many others. During this time, I saw the first flights of the T221 and Concorde 002. Unfortunately, I missed the first flight of the T188 as I was in college at the time but later saw it flying many times.
I still have the toolbox I made in the BAC basic training workshop which I now keep in my 405!