Friday March 18th, 2005|
Today I received the pipe-to-tube fitting I've been waiting on from Spruce. It took a couple of orders to actually get the right piece....not Spruce's fault...mine...I kept ordering the wrong thing! Anyway..it's not that big of a deal. You can't have too many AN fittings when building an airplane.
The fitting needed is the one seen above for the Cessna Pitot. The pitot came from the salvage yard with a nylon fitting/tube on there. Apparantly Cessna says that it's ok to have Nylon. Many folks make aluminum 'heat sinks' coming off the pitot then splice it into nylon tubing (they're afraid the warm air from the pitot will melt the nylon)...but there are FAR more Cessna's flying than RV's...so I think the Nylon for THIS pitot would be fine. Besides, if your pitot system is working properly, the hot air won't travel up through the tube! The pitot system should hold steady pressure.
Here's the part number: AN816-4-4D.
Oh yeah...the fitting goes in there at an angle...it's not an optical illusion in the picture above.
Anyway...I played around with the piece of tubing I had previously desginated for connecting the pitot...and it doesn't work. My main concern is that I can't seem to get the soft aluminum tubing on there without binding it...which seems like a bad thing to me. I'm also concerned about the pitot line and electrical wiring chaffing on the pitot mast.
To make a long story short, I'm seriously considering going with all nylon tubing. Why not???? This will prevent me from having to convert to nylon which has to occur at some point since this is what is used behind the panel.