Aerolite Spitfire

[BarnOwlLover]

Any info or thoughts on the Aeorlite Spitfire, which was an attempt to build a Spitfire fuselage out of Aerolite, which was resin impregnated fiber that was a predecessor to carbon fiber/carbon fiber reinforced plastic. It wasn't mass produced, but was done to see if it could be done if there was a critical shortage of aluminum that could be used to make aircraft structures.

I've seen it referred to in a couple of threads, but not discussed in detail.

 

[FLYBOYJ]

It was a promising experiment and "could have" been used if there was indeed an aluminum shortage, but at the same time "would have" presented issues for field repairs. Here a good discussion on this.

AN ORGANIC SPITFIRE? - Fighters Under Construction in World War Two: Rare Photographs from Wartime Archives

AN ORGANIC SPITFIRE? - Fighters Under Construction in World War Two: Rare Photographs from Wartime Archives - by Graham M. Simons

erenow.net

 

[BarnOwlLover]

One, just the guy I wanted to see Second, I was considering posting that link, but some of the members here already know about the Aerolite Spitfire.

I do wonder, with this being basically new tech back in 1940, what the difficulties would've been, namely would the issues be due to this being new? And how easy (today) is it's to repair composite structures vs aluminum?

 

[pbehn]

One, just the guy I wanted to see Second, I was considering posting that link, but some of the members here already know about the Aerolite Spitfire.

I do wonder, with this being basically new tech back in 1940, what the difficulties would've been, namely would the issues be due to this being new? And how easy (today) is it's to repair composite structures vs aluminum?

It takes years to figure out all the properties of materials and what to do about any problems. Many still say aircraft are made of Aluminium, they arent, they are made of Alloys of Aluminium (and other metals) mainly under the generic name of Dural or Duralumin. Carbon fibre has great properties but in the early days suffered from low impact strength, it was brittle. Ways have been found to overcome this like weaving the CF strands and impregnating them with "stuff". The first aeroplane made out of any new material would be the test bed for all that materials faults and cures. It probably could be done but would mean having a great Spitfire in 1946 and a lot of dud ones before that.

 

[FLYBOYJ]

And how easy (today) is it's to repair composite structures vs aluminum?

Aluminum is way easier to repair. With composite structures (depending on composition) you need a environmentally controlled area, vacuums to apply pressure to the repair area and curing time, let alone the glues and resins to make the repairs. I don't know if there was any thought given on how field repairs would have been made on a Aerolite Spitfire.

 

[pbehn]

Aluminum is way easier to repair. With composite structures (depending on composition) you need a environmentally controlled area, vacuums to apply pressure to the repair area and curing time, let alone the glues and resins to make the repairs. I don't know if there was any thought given on how field repairs would have been made on a Aerolite Spitfire.

Well they didnt make it, so my money would go on field repairs being discussed. They were still figuring out all the ins and outs of making planes out of metal.

 

[FLYBOYJ]

Well they didnt make it, so my money would go on field repairs being discussed. They were still figuring out all the ins and outs of making planes out of metal.

And at the end of the day it was quite evident (even as aluminum aircraft were becoming the forefront of aviation) that an aluminum aircraft would be easier to repair when comparted to other construction methods. Designers even came up with repair manuals to handle basic repairs they felt would be encountered in the field.

 

[BarnOwlLover]

That's the issue I'd have with this (and wood, namely with how say a Mosquito fuselage was constructed), is ease of field repairs. Fighter aircraft in World War II aren't like say modern fighters or say Formula 1 or Le Mans Prototype cars where the facilities are there now to repair that stuff, let alone the ability to send aircraft back to the factory or a factory supported repair base for repairs.

Granted, World War II to a large degree was a war of attrition. To a degree, it didn't make sense to try and repair a damaged plane if one could be made to replace it just as cheaply and quickly, and production was king. That benefited the Mosquito, though it's wooden structure would require relatively intensive care and maintenance for long term use (hence why until recent years there was no fully airworthy Mosquitoes for many years). Not to mention that from what I've read that even though wing repairs were usually a simple carpentry job, fuselage repairs were significantly more intensive and are similar to what have to be done to a carbon fiber monocoque race car as far as basic operations and intensive-ness (different materials and detail techniques, I know, but similarly laborious).

However, like the Mosquito, the Aerolite Spitfire was, one, a war-time expedient, and I'm sure if given time and enough R&D, suitable repair methods would've been developed, but since the Aerolite Spitfire in the end wasn't needed, neither were repair methods.

However, I do think that it's evident that composites like Aerolite and carbon fiber do hold up to long term storage and use better than wood tends to. So it has that advantage, though alloy is probably easier to work with as far as simple repairs and cost.

 

[ThomasP]

An interesting table from a 1937 paper that I ran across a long time ago, but had no real use for until now.

NOTE

The Kraft paper-phenolic material is (I think) what was used for the shell of the UK/US 'paper' drop tanks.

The values for the isotropic Aluminum alloy listed in the table are an ideal, not a normally achievable state in 1937, and are still unusual today.
American WWII era 17S and 24S had UTS values of ~420 MPa and 440 MPa respectively.
Today's 7075-T6 has a UTS value of 572 MPa.

 

[MIflyer]

Multiple efforts along those same lines were undertaken in the USA as well. Ryan built the YPT-25, a wooden two seat primary trainer. Fairchild built some wooden trainer aircraft as well. Bell built the XP-77 wooden fighter. Some T-6's had steel rather than AL skinning on teh wings, Lockheed built those beautiful drop tanks out of stamped steel. And Vultee had a program, too.

 

[wingnuts]

Aluminum is way easier to repair. With composite structures (depending on composition) you need a environmentally controlled area, vacuums to apply pressure to the repair area and curing time, let alone the glues and resins to make the repairs. I don't know if there was any thought given on how field repairs would have been made on a Aerolite Spitfire.

I have had to do a few jobs outside the aviation industry using commercial aluminium, terrible stuff, working with 2024 T3 or 7075 T6 is much easier.

 

[Big Jake]

Multiple efforts along those same lines were undertaken in the USA as well. Ryan built the YPT-25, a wooden two seat primary trainer. Fairchild built some wooden trainer aircraft as well. Bell built the XP-77 wooden fighter. Some T-6's had steel rather than AL skinning on teh wings, Lockheed built those beautiful drop tanks out of stamped steel. And Vultee had a program, too. View attachment 696243 View attachment 696244 View attachment 696245 View attachment 696247 View attachment 696248 View attachment 696249 View attachment 696250

T-6 had a version with wooden rear fuselage.