Tail volume coefficient

[nzhills]

Hi, is there someone out there that knows the reason why the Venom FB1 came out with a tailplane that extended beyond the tails. This also occurred on the NF2. However the tailplane of the Venom NF3 was contained between the tails, i.e. the tailplane spanned from tail to tail, there was nothing beyond the tails. However, the Venom FB4 had a tailplane that extended beyond the tails. Does anyone know why the altering tailplane span exists?
Regards
Mark

[Genghis the Engineer]

No, but the clue may be in your title. Have you tried calculating the tailplane volume coefficients for the variants? Also can you check the aerofoil sections on the tailplanes - a shift of CG range could have necessitated it for example.

G

[Mechta]

David Watkins, in his book 'Venom, De Havilland Venom & Sea Venom, The Complete History', states that the tailplane extensions were removed on the NF.3 to improve rudder and elevator effectiveness.

The FB.4 was a modification of the FB.1 so may have preceded this change.

[URL="https://books.google.co.uk/books?id=FuQ6AwAAQBAJ&pg=PT2&dq=watkins+venom&hl=en&sa=X&redir_esc=y#v=onepage&q=watkins%20venom&f=false"[/URL]

The Venom tail end was redesigned several times through the various models, in an effort to tackle a range of control, high speed handling and structural issues. See: http://naca.central.cranfield.ac.uk/reports/arc/rm/3210.pdf