F-4 Phantom II -- carbon fibre?

[AnotherFSO]

Hello.

I've been re-reading Robert Prest's fabulous book, 'F4 Phantom: A Pilot's Story' (1981 edition) and something caught my eye.

In the early pages he writes of his training on the aircraft (in the first half of the 1970s): "The ground school lecturers have taken me beneath the duralumin and titanium skin to lay bare the metallic innards. They have rationalised the intricate collection of wire, pressed steel, carbon fibre, bakelite and vulcanised rubber that lies beneath that purposefully smooth exterior."

Of course, this was an aircraft that was designed in the 1950s and entered service in the 1960s.

Carbon fibre was still a very new concept in the 1960s and didn't have many practical applications at that time, as far as I know. I know that aerospace companies were beginning to experiment with it, but it wasn't mainstream as it is now.

So my question is: which components of the F-4 were made of carbon fibre? Perhaps by the time Prest flew the aircraft, some parts that had originally been metallic had been replaced with carbon fibre?

Thanks!

[Pypard]

Can't really answer for the F-4, but it's generally accepted that the first racing car to use carbon fibre in its construction was the Lola T70 of 1965. So if it was in use with race car constructors by the mid-sixties, it's easily possible that Phantoms were being manufactured to include it ten years later. Production ended in 1979, so plenty of time to incorporate CFRP into the later models at the very least,

[134brat]

The surface above each main landing gear bay on the F4 was some sort of honeycomb compsite material. Dropping tools on this area was frowned upon as it was easily punctured.

In the 80's l remember the terms GRP and CFRP being used almost interchangeably even though they were not the same thing.

[Jhieminga]

The stuff we know today as Carbon Fibre Reinforced Plastic (CFRP) is based on a 1963 patent from the RAE at Farnborough as far as I know. CFRP applications in civil aviation go back to testing done in the late 1960s and early 1970s, with the first CFRP elevators being tested on a 727 in the late 1970s (see here: https://ntrs.nasa.gov/api/citations/19840019654/downloads/19840019654.pdf). No doubt applications in the military world may go back further than that, but my money would be on the use of glass-fibre based composites in the F-4 (with honeycomb cores, civil designs from the late 1950s use these same materials), with the name CFRP being used incorrectly.

[meleagertoo]

I built a control-line model aeroplane in 1971 or 72 with carbon fibre incorporated in the landing gear. Strips of carbon fibre were realily available, albeit at considerable cost, from Strand Glass, a local resin and glass supplier.

[AnotherFSO]

Thank you, all, for your answers. It sounds like aerospace manufacturers were early adopters of this material -- not surprising, I guess, given its properties.

[treadigraph]

When I was in the sixth form at school we had compulsory Arts Club and Science Society on alternating Friday nights - Arts Club was generally naff (in my humble yet strangely philistine opinion) and to be bunked off, yet SS was often good. One night it was something like "The Invention of Carbon Fibre" and it was presented by one of the Farnborough scientists who had been part of the team. My memory is of a little bloke who decidedly resembled Mr Honey as visualised by Nevil Shute rather than as portrayed by the rather tall James Stewart... Anyway his presentation was easily the most entertaining and interesting I ever attended - "me and the boys were sitting around one morning wondering what to do when one of us suddenly said 'let's invent carbon fibre!' - so we did..." Informal chat afterwards with coffee and biccies.

The payoff was that a dozen or so interested sixth formers were subsequently invited to Farnborough to see round the portacabin (well, it might have been a slightly more substantial building but not much) where it had all happened and shown the processes, artefacts and so on. I remember there was a beautiful glass fibre scale model of a Slingsby Kestrel or similar; I presume the real thing has a carbon fibre main spar? There wasn't enough space for all of us to do whatever the second part of the visit was, so I generously volunteered to be part of the smaller group and visit Farnborough's control tower - we had a chat with the airfield controllers and also with the wizened troglodytes manning Farnborough Radar a floor or two below, which (allegedly) me and my spotting school mates listened to avidly on our airbands when whiling away weekend afternoons watching the skies. While I was talking to the duty controller, G-ABLS or a similar reg called up "What on earth is that?" said the controller after initial acknowledgement. "It's a Puss Moth" said knowledgeable me... Who knows, I may well have met Chevvron of these pages. Great afternoon out!

[AnotherFSO]

Thank you, treadigraph -- that must have been a great experience for a high school kid!

[India Four Two]

I remember there was a beautiful glass fibre scale model of a Slingsby Kestrel or similar; I presume the real thing has a carbon fibre main spar?

Good guess! :)


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