gschuld
Well-Known Member
Odd question of the week time again:nervous:. So I will have a pair of aluminum fuel tanks mounted in the stub wings that will likely be accessible through flush "hidden hinge" type access doors. They would require a simple remote wire release pull just like a typical oil access door. So I was thinking
onder:ara:, what if the access doors(already to be fwd hinged/opening) were set up to double as speed brakes. Mechanically, it would only seem to really involve having a more robust opening /closing mechanism rather than the simple pull release to operate it. The only obvious difference from the normal speed brake operation would be it's location. The fuel cap needs to be positioned between 40-50 of the wing's chord, rather than the 60-70% of the chord more typical of the speed brakes that I have seen. Would that be a serious issue? Also, the fuel caps will be 18" outboard of the fuselage sides. I assume that the turbulence created by the inboard speed brakes would not interfere with the airflow over the tail surfaces too badly, since I know of at least one plane that uses a fairly large set of trailing edge pivoting speed brakes and reports no handling problems(below). That set would probably create 10 times the turbulence compared to a set of fuel door/speed brakes.
If this is feasible, it may be worth increasing the size of the speed brake a bit more than the minimum necesssary(to perhaps 3 1/2"tall x 6-7" wide) to both increase the brake performance some and to have a bit more access to the top of the tanks. It may allow me to have a top mounted fuel pickup, float sender fixture mounted right next to the fuel intake for easy removal for maintenance accessibility. Anyway, any thoughts?
George
http://preciseflight.com/ufiles/AOP...ticle_08.05_(low_down_on_go_down).reprint.pdf
onder:ara:, what if the access doors(already to be fwd hinged/opening) were set up to double as speed brakes. Mechanically, it would only seem to really involve having a more robust opening /closing mechanism rather than the simple pull release to operate it. The only obvious difference from the normal speed brake operation would be it's location. The fuel cap needs to be positioned between 40-50 of the wing's chord, rather than the 60-70% of the chord more typical of the speed brakes that I have seen. Would that be a serious issue? Also, the fuel caps will be 18" outboard of the fuselage sides. I assume that the turbulence created by the inboard speed brakes would not interfere with the airflow over the tail surfaces too badly, since I know of at least one plane that uses a fairly large set of trailing edge pivoting speed brakes and reports no handling problems(below). That set would probably create 10 times the turbulence compared to a set of fuel door/speed brakes.
If this is feasible, it may be worth increasing the size of the speed brake a bit more than the minimum necesssary(to perhaps 3 1/2"tall x 6-7" wide) to both increase the brake performance some and to have a bit more access to the top of the tanks. It may allow me to have a top mounted fuel pickup, float sender fixture mounted right next to the fuel intake for easy removal for maintenance accessibility. Anyway, any thoughts?
George
http://preciseflight.com/ufiles/AOP...ticle_08.05_(low_down_on_go_down).reprint.pdf
