National Aeronca Association Bulletin Board

Just after takeoff, am consistently experiencing approx. 300 rpm drop during climb with C90 engine. Immediately level off and full power is restored after about 20 - 30 seconds. Can repeat at altitude shortly after initiating a climb. Also, no issue in level flight at full power (2475 rpm). Carb hea...

I know a Champ owner who rib-stitched the wings 10 years and 400 hours ago. He still owns the plane and there have been zero problems or issues. He protected sharp edges with anti-chafe tape. The pre-war Chiefs with wooden ribs were rib-stitched. Obviously, Aeronca went to the #4-40 screws to attach...

Installed a vacuum T & B in my 7CCM which was a total bust. Apparently the air flow around the cowl separated along the side of the fuselage where the venturi was located. Tried 2 different 2" venturis and 2 T & B's in all combinations: not enough suction. Removed the internals from an ...

Hi, The disk on my Champ measures .508" o.d. x .196" wide, including paint. It also has a set screw which appears to be a #4 for securing at 1/2" forward of the holes. I would think the disk is made of brass, same as the tube, to eliminate galvanic corrosion. Also, stainless steel sho...

You might also consider converting an O-200 to a C-90, the only significant differences being camshaft and carb (different main jet). Advantages: Can use a 72" dia. prop and no annual spar inspections. The 7/16" holes in the standard mount can be bushed for 3/8" bolts. The lower cowl ...

Anyone else notice that the gear bolts specified in the 7AC service manual are too short? Adjacent to the nut, the transitiion from bolt shank to threads lies within the gear fitting. This creates a greater clearance between bolt and fitting, and a reduced contact area (at least until the bolt and /...

Gus,

Believe the rationale is something like: "If 4 plys are good then 6 must be even better." Happy flying with your Champ!

Roger

Gus, Switched to 4 ply tires when I learned (from Lee at Specialty Tire) that the recommended pressure for 6 ply tires is 30+ psi and they are considerably stiffer than 4 plys. My grass strip is not world's smoothest; taxi shock was noticeably less with the 4 plys at 15 psi. Whether or not the highe...

Gus, Been running 15 psi in the 8.00x6, 4 plys on my Champ for the past 7 years with no problems. However, prior to 1999, had 6 ply tires at 20 psi and developed a crack in a wheel flange. A downside of higher pressures is increased stress in the root of the flanges, where they are prone to cracking...

Would appreciate receiving instructions, or advice on where to find, for installing Federal Model SC-1 skis on a Champ. Thanks! Roger