At 07:13 PM 10/13/2014, you wrote: >Ok looking at the plans its not clear what size tubing is used for the >pitot tube and what material to use. What is the accepted material and >size? >Second, what is the ceiling flange made of. I'm talking about the type >that is a continuous flange that goes around the entire fire wall. I'm >thinking a 1"x1" aluminum angle. But how thin can I go? .040"? Or >thinner? >Phill Hill +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
For my pitot and static I used thin aluminum from the hardware store, the hobby area where they sell balsa, brass tubing, etc. , 1/4" as I recall. Take a piece of hose with you and find the size that the hose fits into and gets really tight after inserted an inch or so. That makes for an easy sealed connection. Two holes, in tandem, at each 90 degrees on the static works fine. I'm not sure why you want a flange around the entire firewall. Your firewall is sealed and if the stainless steel is flush with the edges you don't need additional sealing. I used .125 aluminum angle to mount the cowling using one 3/16" bolt on each and one screw to keep it from rotating, thus saving an ounce or two of weight. https://dl.dropboxusercontent.com/u/32133949/IMG_8083.jpg http://krgathering.com/picture_library/Gathering%202011/N211LF/RRL_2710.jpg I used 4 brackets on the bottom cowl and I think maybe 7 over the curved top cowl. A small thin square of aluminum on the inside of the cowl will help to spread the stress on the fiberglass. I buried a washer in the fiberglass under each screw head. Results: 500 hours and the cowl is in as good shape as the first flight. It fits nicer and installs easier than any cowl I've ever worked on, especially those nasty ol' RV cowls with all those hinge pins or those Cessna cowls that flop around, crack, lose fasteners, and use an entire toolbox of swear words to install. :-) Larry Flesner
