Due to the Coronavirus pandemic the Associaton has not been able to
hold its usual Wednesday afternoon meetings at the YMCA Hawker Centre
in Kingston but as members have become familiar with the internet Zoom
facility the Committee and Chairman decided to see if Members would
like to see talks on this medium. The Rev Dave Priddy already used Zoom
for his church so he offered to host our first experiment, a talk by HA
Member Dr Michael Pryce, which was Zoomcast on December 9th.
After gaining a BA in history at Manchester
University Mike was
awarded an MSc and Diploma at Imperial College London in the history of
technology, followed by a DPhil in science and technology policy at
Sussex University. At Manchester Business School he became a research
fellow and at Cranfield University he was a lecturer at the Defence
Academy at Shrivenham, became accredited as an Independent Scientific
and Technical Advisor to the MoD and was a Senior Air Systems Analyst
at the MoD Defence Science & Technology Laboratory (DSTL). He has
also advised BAE Systems on project design matters and is about to
start working for the company.
Designing, building and operating aircraft is not a
pure science
and can be accomplished in various ways. The practical way things were
done at Kingston went against the scientific methods adopted elsewhere.
Post WW 2 the UK looked at the application of science to aircraft
design. The origin of the different approaches at Kingston and Warton
was in the 1940s, not in culture but in what they were doing and why.
The VE Day flypast in 1946 illustrated the fact that
the war was won overwhelmingly by piston engined aircraft and in 1945
the RAF had as many Gladiator biplanes in service as jet propelled
Meteors. Few new wartime ideas were developed or applied during the
war; radar, the jet engine etc were pre-war developments. WW 2 was a
war of production, not innovation. That wars are not won solely by
fighting but also by production was recognised by all combatants.
During the war there was incremental improvement of existing aircraft
with increased mass production. So, applied science was a novelty and
the RAE was mainly concerned with improving existing aircraft in small
steps in close relationship with the RAF. Doing the radically new
things, like the Miles M.52, were side issues.
Post war there were new technologies - the jet
engine, use of radar inside the aircraft. There were huge existing air
fleets which had cost a lot of money. There was no threat of attack on
the horizon so what should the Government do? Rely on the piston
engined aircraft or embrace the new technologies? It was decided to go
for the new and throw away many of the existing types, even in those
times of great austerity; to maintain the production capacity for a
possible war and to innovate by design.
Official RAE missions to Germany had been shocked by
the new technologies of swept wings and jet or rocket propelled
fighters. Examples were brought to Farnborough and exhibited. The new
technologies were clear and the policy was adopted by Britain. The RAE
saw they could take a leading role in designing aircraft, taking it
away from industry which would productionise the designs. Sir Stafford
Cripps wanted to nationalise as well, but it did not happen.
The biggest new threat at the time was the atomic
bomb where one aircraft and one bomb could do what had needed thousands
of bombers using conventional bombs, as demonstrated by the destruction
of Hiroshima. Only the USA and the UK had nuclear weapon technology but
Russia knew what was going on through espionage Other countries could
develop atomic weapons against which Britain needed a defence; they
needed to shoot down almost all atom bombers.
In WW 2 to shoot down 10% of raiding bombers was an
amazing result and 3 - 4% was considered quite good. Against atom
bombers it would be necessary to down 90% (not of 1000 but of 10, 20 or
30, say) to avoid mass destruction. This was the problem the RAE
focused on. To achieve a 90% bomber kill rate needed high altitude
interception using integrated radar and weapons. The solution needed
the application of science which industry could not do; a scientific
institution was needed to pull all the technologies together, like the
RAE.
The RAE was not alone in this view. Air Chief
Marshal Sir James Robb, Commander in Chief Fighter Command, published a
paper addressing the interception problem and 90% success rate. He
foresaw new technologies including airborne control units (AWACS today)
over Europe, far enough from the UK to identify the raiders early; UK
ground based radars would be too late. He saw the need for UK based
supersonic fighters and stowed parasite fighter carriers loitering far
away to ensure early interception, and for weapons powerful enough to
guarantee instant destruction of the bombers, possibly long range,
radar guided missiles with proximity fuses. Even the installation of
4.5 inch guns in fighters was considered; one hit would bring down a
bomber.
In Germany the RAE mission also spoke to people and
spotted Hans Multhopp, a maths prodigy and student of the
aerodynamicist and mathematician, Ludwig Prandtl at, Gottingen
University. Multhopp worked under Kurt Tank at Focke-Wulf where he
conceived the 1944 Ta183 with 42 deg swept blunt leading edge wing,
tall, highly swept fin carrying a highly swept tailplane on its tip.
The short fuselage housed a jet engine fed by a nose intake. It was an
‘emergency fighter’ to defend the Reich from expected B-29
Superfortress raids by flying high, diving fast through the Mustang
escort fighters to hit the bombers and fly clear. It proved difficult
to make the design work aerodynamically and, especially, structurally.
However, this aircraft looked like what the UK needed to leapfrog to a
new level, so Multhopp, with his assistant Martin Winter, was brought
to RAE in 1946. Multhopp, from an apparently ultra right pro-Nazi
family and seemingly unperturbed to see thousands of Poles and
Hungarians as slave labour, was difficult to work with.
The highly swept wing had quite a large leading edge
radius which created a high leading edge suction to offset the induced
drag. The ‘T’ tail was clear of fuselage and wing turbulence to reduce
drag. Multhopp hated delta wings and won over the RAE who set up an
advanced study fighter group which produced a document describing a
configuration very similar to the Ta183. This was distributed to many
UK fighter companies who were invited to make proposals based on this
configuration. Hawker’s was the original P.1067 with nose intake and
‘T’ tail, and English Electric’s was what became the Lightning.
Armstrong Whitworth and Fairey also submitted designs. Multhopp had
convinced the RAE that ‘T’ tails were best and later many UK aircraft
used them; eg Buccaneer, Javelin and many airliners.
The RAE commissioned Shorts to build a low speed
wooden aircraft with adjustable wing sweep and tailplane position, and
English Electric to build a high speed test vehicle. At EE Freddie Page
cut the wing tips to give aileron hinge lines at right angles to the
fuselage and moved the tailplane to a very low position. Kingston also
lowered the tailplane, reduced the wing sweep, and replaced the nose
intake with two side mounted wing root intakes for many sensible
reasons.
Highly swept structures are very difficult to design
and are heavy. At Warton EE had to work very hard to do the structural
analysis and settled on the ‘relaxation’ technique developed at Oxford
in 1938. However, the mathematics was very laborious and needed to be
speeded up; but how? A 1930s paper by Alan Turing led to the first
digital computer, ‘Pilot Ace’, at the NPL in Teddington., and the
‘relaxation’ method was something he wanted to tackle. EE’s Ivan Yates
and others used ‘Pilot Ace’ to solve their wing maths and flutter
problems. It took two years.
Meanwhile Hawker had flown the Hunter. Ralph Hooper,
then in the Experimental DO, had designed and stressed the wing root
spar fixture in a couple of weeks. Hawker got some 2,000 Hunters, with
four 30 mm cannon to destroy bombers. into service before the RAF had
their first Lightning.
The nuclear bomber threat which the Lightning was
designed to counter had meanwhile largely gone away and Duncan Sandys’
1957 White Paper deemed it would be Britain’s last manned fighter. The
Hunter proved to be very adaptable to new roles because underwing store
carriage was easy, and also easily modifiable because of its simple
structure where possible failure could be predicted. The Hunter was a
flexible, simple design lending itself to incremental improvement and
requiring no new science or design tools. The Hunter demonstrates that
you don’t have to go to the most sophisticated technologies; there are
simpler ways. Good design tends towards simplicity rather than creating
something complex and having to invent new solutions.
The Lightning was twice as fast as the Hunter, cost
four times as much and was used for half the time. The Hunter generated
more income for the UK than did the Lightning.
Fighter procurement has moved away from the WW 2
concept of improvement and mass production to ‘silver bullet’ projects
incorporating enormous technologies, purchased in small numbers and
costing a fortune. The tendency is to go for new advanced technologies
rather doing what is possible today. Government policy says science is
the answer so if we throw more money into science and innovation then
things will be better. Perhaps we should focus on what can be produced
today because the future will be different to what is imagined.
Multhopp’s thinking was imbued into Warton leading
to aerodynamics-led science, believing in new techniques and
technologies rather than making use of what is available today.
Kingston took the simple, intuitive physics approach rather than
complex mathematical analysis.
Post war UK policy was to try to fly too high, too
close to the sun like Icarus. This was too hard and too time consuming.
If the UK had done more Hunter type projects and fewer of the Lightning
type which litter the ‘project cancelled’ genre of books which
chronicle the leapfrogs that never happened, we might have had a very
different aircraft industry today.
After a short Q & A session, interrupted by
internet problems, Frank Rainsborough (our recently appointed Speakers
Secretary) gave the vote of thanks to Mike Pryce for his engrossing
talk, thanked Dave Priddy for hosting the Zoom meeting which had been
largely successful, and Chris Roberts for proposing it. There were 38
participants.