Sorry to try and revive that dead thread, but I think I might have a lead on what John Wimpenny said about the Hornet’s ailerons in the DH Hornet book and why he didn’t approve of the type used on the Hornet.

I was asking about some of the developments of the DH Vampire and Venom in another thread, and the subject of power boosted ailerons were brought up. It seems that DH were investigating that issue shortly after World War II ended, and the DH Swallow research aircraft lead DH to put more research into the project after John Deery flew the Swallow.

This connects to the Hornet’s aileron issues in that DH suspected that as speeds rose that things such as compressibility and flutter (a then little known aspect of transonic flight) would become major issues. The Venom there for was fitted with ailerons that had the convexity deactivated by extending the wing trailing edge back a certain amount.

Could the Hornet’s ailerons been experiencing the effects of flutter at high speeds due to compressibility or some other factor? Because DH went from using convexity ailerons on the Vampire and Hornet, but ditched it on the Venom and also used power boosted controls, in part it seems to counter high speed flutter issues and compressibility, or at least that’s the problem that they were hoping to solve or reduce. It may not have been a big issue on the Hornet (which combined with it rapidly approaching obsolescence is why DH didn’t put a lot of effort into fully solving the issue), but it seems to maybe have pointed out something that would become a big problem later as jet engines became more powerful and new jet fighters and bombers became much, much faster than any piston engined fighter and the WWII era jets.

Edit: I finally found out what convexity is and why it was felt by DH to be a not very desirable feature. Convexity was basically fitting a blunt trailing edge to control surfaces (namely the ailerons) instead of the then more common tapered edge. This was felt, due to production issues related to the design, to be a source of trouble on the Hornet according to Wimpenny’s commentary. How this was remedied on the DH Venom was that the aileron’s TE was extended back to form a tapered edge, like on a wing.

It would be interesting of Mr. Collins was some day able to find a set of Hornet ailerons in good to decent condition and compare them to the Mosquito, Vampire, and Venom ailerons as far as the trailing edges go.