National Aeronca Association Bulletin Board

Have seen this happen a lot and we have to remember that in many cases, these spinners are 70 years old.

Glad to have someone making new ones!

It is amazing that aircraft of this age are still in flying condition, consider the many environments they travel too and live in. Maintenance, repairs and modifications play an important role in the life of these aircraft.

Aeronca chose materials for the 11AC spinner and bulkhead not common in the spinning industry for light aircraft. I would assume they chose these materials for a strong light weight installation with the McDowell starter.

The original bulkhead was spun from .040" 5052-0 or 2024-0 alum. and the spinner dome .051" 3003-0 alum.
Other aircraft manufacturers chose 1100 alum. with thicker material: example (Funk Aircraft- bulkhead .080", spinner dome .063")

We have also introduced the metal propeller into the equation, not as forgiving with vibrations. These airplanes have served us very well over the years!

A third style 11AC spinner bulkhead, similar to the shape I am tooling for. Having access to these original bulkheads helps in the design process. I wished that I could talk to some of the factory craftsmen. Have not found a drawing for this one, could be a design sketch, sometimes called out in drawing changes.

"If anyone has a bulkhead like this that is not in use, I would like to purchase or borrow. Having actual parts helps in the PMA process"

11AC Spinner Assembly Update:

The new tooling is progressing in a positive direction! Awaiting spacers for the tapered shaft installation.

I am working as hard as possible in the shop to provide a quality Spinner Assembly. Please be patient with me.

I have rotated to night shift and rotating weekends in the R&D department at work. My schedule is a little confusing.

Thanks for your patience!

Charles

I will have some time the next couple days in the shop at home to work on the spinners.

Spacer material for the tapered shaft engine cost $200.00 a foot, using the material spec. that Aeronca used. Aeronca believed in quality material and parts!

Finishing up a new spoon tool to lay down the material to the mandrel. Working with the aluminum alloys that Aeronca used has required specific shaped spinning tools to lay the material to the mandrel without work hardening quickly.