Should the header tank be placed higher than cab in ducted fan?
Can ducted fan jets make loop like prop planes ? Thanks in advance for the answers
Rich

If you don't plan on running the main tanks dry, it does not really matter what height the header tank is. It looks like a fat piece of fuel line to the fuel flowing through. If you do get a mixture change after adding a header tank, it's because the length of fuel line between the main clunk and the engine changed, or the header fixed a foaming or bubble problem with the fuel feed.

If you run the main tank dry, then the header is the only tank supplying fuel. If it's higher than the main tank, then you will go rich when running on the header. If it's lower than the main tank, you will go lean.

So, mount the header tank higher than the main tank. If you run the main dry, then the engine getting a bit richer will tell you it's time to land. This assumes that you're flying upright at the time, of course.

Thanks Phil. I will place the header tank higher the cab.It will provide the fuel for in-flight mixture control valve before fuel comes to cab. Can ducted fan jets loop like pro planes?
Rich

Rich,

I left the looping question to those that have actually flown one.

Rich - yes, DF's will do a loop... assuming that you have enough speed & power to get you over the top of course (which most of them do).

Gordon