Bearhawk build tour

[@Kevin_747]

Nice work. I've been building a Patrol forever. I bought the plans in' 02 and didn't start on the fuselage till 08. Scratch building never ends. I do have a Champ to fly.

[@dylantosta4218]

What's the whole airframe material made of ? Is it aluminum or Chrome steel ?

[@boymugnaadventure2967]

New subscriber sir...

[@DuneMoose5]

Are you building here in AK? I'd love to come by; I have been wanting to build a BearHawk!

[@akschu1]

No, I live in WA now. After 25 years I was good leaving AK.

[@benc1103]

Thanks for the tips and modifications. Half inch fuel line for the drop then 3/8" fuel line in the horizontal probably doesn't make a difference. With the tanks well above the rest of the fuel system, there is plenty of head pressure. It's the height of the tank that drives the pressure. But your changes in diameter of the fuel line won't hurt (well, your hands may hurt bending half inch 5052 :) It's been a long time since by hydrodynamics courses in college, but that's my take. None of the 100 series Cessna's or other high wingers have an issue with fuel feed. But I like that you gave it some thought. Very nice work on the build and I like your attention to detail. Especially not doing the "bent over tube edge" for the cargo door latch pin. What's the tubing painted with? Looks like Rustoleum Hammer paint. It looks too nice to have to cover any of it up.

[@akschu1]

Should I unport a tank and suck some air, I think the 1/2 line will help it clear the bubble before it gets to the fuel pump. Also, remember, anything flows great with full tanks, but I need good flow with 2 gallons in the tanks. The 100 series Cessna doesn't put out the same HP as a bearhawk unless you get to the 185 or a p-ponk 180, and from what I understand, those require fuel pumps, even with a carb. Even the 170 with a 360 has a fuel pump. The tubing is powder coated at Advanced Powder coating in Big Lake, AK. The same people that powder coat Airframes fuse and Airforms baffles. I'm not going to run much interior. the headliner is my tommy bahamas fabric installed above the tube.

[@benc1103]

@@akschu1 I gal has the same head pressure as 25 gal for a given height (4 or 5 ft. OK, the fluid level of 25 gal will be some 8 inches higher :) Height is what gives you the pressure (example: a 1 sq inch column of air weighs about 14.7 lbs. That equals 14.7 psi. Doesn't matter how much air is up there "in the tank"). Same with fuel. If you want more fuel "available" (as needed with high hp engines) then use 1/2 inch all the way to the engine (don't neck it down to 3/8" if it needs 1/2"). But at least you'll have plenty of fuel at the selector (where all the bends in the fuel line don't help matters). All this is irrelevant when you fly upside down :) Thanks for the powder coating reference.

[@benc1103]

I forgot to add: I think the Cessnas with fuel pumps have fuel injected engines. My 300 hp radial engine Cessna 195 sucks over 30 gph at takeoff power. It doesn't have a fuel pump. When I open the firewall fuel drain valve, fuel comes out as if from a hose. Thats about 5 feet of head pressure.

[@akschu1]

@@benc1103 195 is a seriously cool airplane. I have a 170A and love it, but it will be sold when the bearhawk is done.

[@macjohnson4326]

So are you planning on having a yaw damper? Is that the purpose of the rudder servo? Or is that for rudder trim?

[@akschu1]

The bearhawk has a lot of adverse yaw, so I didn't think the autopilot would fly the airplane without a rudder servo. It will have a yaw damper, but I doubt I will use it.