Plastic Composite Spitfire - 1940

[HarryMann]

Plastic Spitfire
One Type 300 fuselage was constructed using Aerolite plastic material in August 1940, as an insurance against aluminium shortages. Not flown.Would that be the first attempt at a compositea/c fuselage (other than wooden hybrids)?

Is it common knowledge?

Was it a World first even?

[seacue]

I don't know what you mean by "wooden hybrids", but there were moulded plywood fuselage aircraft back as far as 1919. Jack Northrup did one for the Loughead (Lockheed) company.

Molded Plywood Construction (http://www.aviation-history.com/theory/plywood.htm)

[cwatters]

Check out Norman de Bruyne inventor of Aerolite glue and Gordon-Aerolite one of the first non wooden composites used for aircraft. Was used on a few Miles aircraft before the attempt on a Spitfire. The problem was the lack of an adhesive to join things to the Gordon Aerolite. That took until 1942 to develop. There is a photo on page 230 here of part of the spitfire. looks like it wasn't really moulded. Rather it was assembled from cut parts.

Handbook of adhesives and sealants - Google Books (http://books.google.co.uk/books?id=9XFD8ZsZzAsC&lpg=PA230&ots=-mMlSVNGIm&dq=Gordon%20Aerolite%20spitfire&pg=PA230#v=onepage&q=Gordon%20Aerolite%20spitfire&f=false)

Awards in adhesion and adhesives | IOM3: The Global Network for Materials, Minerals & Mining Professionals (http://www.iom3.org/content/awards-24)

Norman Adrian de Bruyne (1904 - 1997)

Born in Punta Arenas, Chile on 8 November 1904, Norman de Bruyne was a man of outstanding achievements and in 1967 he was elected to Fellowship of the Royal Society. The citation read:

‘Distinguished for his practical application of science to certain problems in aircraft construction, especially the use of plastic materials and adhesives…. ’

He was a prolific inventor, an engineering entrepreneur and one of the earliest and most influential advocates of synthetic adhesives for use in demanding and novel engineering structures, especially aircraft.

It was in October of 1923 that de Bruyne went up to Trinity College, Cambridge, to read Natural Sciences and in 1927 he took Part Two of the Natural Sciences Tripos and obtained a First. In September of 1927, de Bruyne continued at Cambridge with his PhD research, studying field emission, at the Cavendish Laboratories under the supervision of Lord Rutherford. In 1928 de Bruyne published his findings in the Proceedings of the Royal Society. He also wrote up his research as a thesis for the Trinity Fellowship and in September 1928 was duly elected a Prize Fellow of Trinity College. De Bruyne took his MA and PhD degrees in 1930. He continued to work at the Cavendish until 1931.

The turning point in de Bruyne’s life was initiated by a ride in a de Havilland Moth aircraft, at Fen Ditton just outside Cambridge. De Bruyne then learnt to fly and went solo after 12 hours of instruction. It was at this time that he changed from being a physicist to an ‘engineer-entrepreneur’ and he established the Cambridge Aeroplane Construction Company in 1931, which became Aero Research Ltd in 1934. In connection with this latter company he made many novel and major advances in the design and construction of aircraft structures. He designed a four-seater, low wing monoplane at a time when biplanes were de rigueur. He called this aeroplane the ‘Snark’ and it embodied the extensive structural use of stressed plywood made using the new durable and strength-enhancing phenol-formaldehyde resins. It flew for the first time in 1934 and gained an airworthiness certificate in 1935.

Amongst many other intriguing technical challenges, he successfully investigated the use of reinforced phenol-formaldehyde resins in the manufacture of variable pitch propellers for the de Havilland Aircraft Company. The attraction of this material was that, with a density of about a one half that of aluminium alloy, centrifugal forces at the root were correspondingly reduced.

Synthetic urea-formaldehyde systems were also developed and he named them ‘Aerolite’ adhesives. These latter adhesives replaced old-fashioned materials based on natural products which were subject to degradation and therefore unreliable. The new ‘Aerolite’ materials were approved for use in aircraft by the Air Ministry and subsequently used extensively in aircraft construction (‘Horsa’ gliders and the ‘Mosquito’ fighter-bomber for example) and in furniture construction. In the early 1940s, de Bruyne developed a ‘strip heating’ procedure that reduced cure times for ‘Aerolite’ adhesives from hours to minutes.

His work on propellers led to the development of the first reinforced composite material [‘Gordon Aerolite’: a flax reinforced phenol-formaldehyde resin matrix] which, in the early-1940s, was used in the construction of tailplanes for the Miles ‘Magister’ trainers and spars for the Bristol ‘Blenheim’ bombers. Analysing the bolted box designs for the tailplanes led de Bruyne to two conclusions:

Drawing on his work, where sandwich panels with light-weight cores, including balsa wood, were produced to give stiff but lightweight structural panels for wooden aircraft, he realised that an [aluminium] honeycomb material would be very efficient in stiffening these components without appreciable weight gain. He patented this idea in 1938 but it wasn’t until the late 1940s/early 1950s that honeycomb was first used on a large scale; almost simultaneously in the UK and the United States.

Secondly, de Bruyne concluded that there was a real need for an adhesive to bond Gordon Aerolite panels together, to replace the weighty and cumbersome bolts. He and a colleague set about the problem and achieved success within about six months through the development of an adhesive based on a phenol-formaldehyde resole resin coated with a polyvinyl formal powder. By February 1942, aluminium alloy lap joints were prepared with breaking stresses of over 2000 p.s.i. (~ 13.8 MPa). This was the first modern, synthetic structural adhesive for metals and was named ‘Redux’ standing for Research at Duxford. It was first used to bond thousands of ‘Cromwell’ and ‘Churchill’ tank clutch plates and then in the ‘Sea Hornet’, ‘Dove’ and in its film format, the ‘Comet’ It was also used in the construction of Donald Campbell’s ‘Bluebird’. ‘Redux’ is still used widely today.

The Flight Archive has a pdf article on Gordon Aerolite by Bruyne published in 1939. It also refers to his earlier material "Cord" of 1937.

gordon aerolite | fig | spruce steel | 1939 | 0077 | Flight Archive (http://www.flightglobal.com/pdfarchive/view/1939/1939%20-%200077.html)

On the second page he says..

Some may be disapointed at not seeing pictures of the production of complete moulded wings and fuselages. I do not think, myself that this is the way in which develoment will take place in the immediate future"..."it does seem difficult to visualise anyone (except possibly, a communistic or totalitarian government) being prepared to lock up thousands of pounds of capital simply to produce one particular size and shape of wing or fuslage. At any rate, at the moment I do not think the moulding of really large components is a profitable line of development to persue.

How times have changed.

[Brian Abraham]

The book "Spitfire - The History" by Morgan & Shacklady has four pages of text and photos devoted to the aircraft. Don't know if the Mods would appreciate clogging up the system with scans. Anyone interested send a PM.