Bristol 188 was a British supersonic research aircraft built by the Bristol Aeroplane Company in the
Its length, slender cross-section and intended
purpose led to its being nicknamed the "Flaming Pencil".
Design and development
The aircraft had its genesis in Operational Requirement
330 for a
which eventually developed into the Avro
. As the 730 was expected to operate at high speeds for
extended periods of time, more data was needed on high-speed
operations, leading to Oerational Requirement ER.134T for a testbed
capable of speeds greater than Mach 2
The aircraft was expected to run at these speeds for extended
periods of time, allowing it to study kinetic heating effects
on such an
Several firms took interest in this very advanced specification
eventual contract (6/Acft/10144) was awarded to Bristol Aircraft in
Bristol gave the project the type number 188, of which three
aircraft were to be built, one a pure test bed and the other two
(constructor numbers 13518
) for flight
testing. Under contract number KC/2M/04/CB.42(b) serial numbers XF923
were given on 4 January 1954 to the two that would
fly. To support the development of the Avro
Mach 2 reconnaissance bomber, another three aircraft
were ordered (Serial Numbers XK429
). The order was cancelled when the Avro 730
programme was cancelled in 1957 as part of the review of defence spending
The advanced nature of the aircraft meant that 12% chromium stainless
with a honeycomb
centre was used for the construction of the outer skin, to which no
paint was applied, but problems with the new Argon arc welding
known as puddle welding
caused long delays
and was less than satisfactory. The W. G.
much technical help and support to Bristol during this
refrigeration system were designed and fitted but were never tested
in the environment for which they had been designed.
engines were at
first selected to power the 188, but five engine combinations were
evaluated: two with Rolls Royce
200s, two with the de
Havilland Gyron Junior
and one with an AJ.65
, the last disintegrating on test. But
the final choice for the 188 were two 10,000 lbf (44 kN)
Gyron Junior DGJ10Rs developing
14,000 lbf (62 kN) of thrust on reheat
at sea level and 20,000 lbf
(89 kN) at Mach 2 at 36,000 ft (11,000 m).
Unfortunately this choice of powerplant resulted in the 188 having
an endurance of only 25 minutes, which was too little time for any
serious high speed research. Test pilot Godfrey Auty reported that
while the 188 transitioned smoothly from subsonic to supersonic
flight, the Gyron Junior engines were prone to surging beyond that
speed, causing the aircraft to pitch
Testing and evaluation
Farnborough in May 1960 saw the first aircraft delivered for
structural tests before moving on to RAE
XF923 undertook the first taxiing
trials on 26 April 1961 but the first flight
was not until 14 April 1962 due to problems encountered.
had its first flight on 26 April 1963 managing to
reach a speed of Mach 1.88 (2,300 km/h) at 36,000 ft
(11,000 m). The longest subsonic Bristol 188 flight was only
48 minutes in length, requiring 70% of the fuel load to be expended
to attain its operational altitude.
The project suffered a number of problems; the main being - as
mentioned above - that the fuel consumption of the engines didn't
allow the aircraft to fly at high speeds long enough to evaluate
the "thermal soaking" of the airframe, which was one of the main
research areas it was built to investigate. Also, the takeoff
speed was nearly . Though it was eventually
abandoned, the knowledge and technical information gained was put
to some use for the future Concorde
program. The inconclusive nature of the research into the use of
stainless steel led to Concorde's being constructed from
alloys with a Mach
limit of 2.2.
Experience gained with the Gyron Junior engine, which was the first
British gas turbine designed for sustained supersonic operation,
later assisted with the development of the Bristol (later Rolls
Royce) Olympus 593
which was used on both Concorde and the BAC
In total the project cost £20 million . Various proposals to
develop the 188 were considered including: ramjets
variants. One serious proposal involved the fitting of "wedge" type
intakes, but all development was terminated in 1964, the last
flight of XF926 taking place on 12 January 1964.
1966, both 188 fuselages were transported to the Proof and
Experimental Establishment at Shoeburyness, Essex to act as targets for gunnery trials, but
during 1972 XF926 was dismantled and moved to RAF Cosford (minus engines) to act as instructional airframe
8368M, and is preserved at the RAF Museum, Cosford near Wolverhampton. XF923 was subsequently scrapped at Foulness.
Specifications (Bristol 188)
- "Bristol Aircraft." Gloucestershire
Transport History. Retrieved: 5 January 2008.
- Winchester 2005, p. 198.
- Winchester, Jim. The World's Worst Aircraft: From
Pioneering Failures to Multimillion Dollar Disasters. London:
Amber Books Ltd., 2005. ISBN 1-904687-34-2.