Just a general question. How do determine the amount of side thrust degree needed for a propeller-powered plane? Is there a formula to calculate the value?

Trial and error is really the only way. Take some washers with you to the field as well as a trim chart. The trim chart will tell you what maneuvers to do to check the thrust setting.

Use the washers behind the engine mount to make adjustments. Once you're satisfied, sand a plywood wedge to replace the washers. It will support the engine mount better and be more consistent. The washers can start to sink into the firewall over time.

Howdy Cafeenman? any chance I could download one of these trim charts you mentioned. Regards, John.

Go to Great Planes web site and download the manual for one of their aerobatic planes. For example, the Tracer. There is a trim how-to and a trim chart.

John - I don't have one, but there may be one on the GP site as Jim said. If you don't find one there, just do a search for "trim chart" AND aerobat and you'll find them.

Thanks Fellas

The manuals do show how to check for proper downthrust. How do I check if right thrust is proper?

Both right thrust and down thrust are covered on a good trim chart.

I just did a quick search and found several results. I didn't read any of these over, so I can't say if they're right or not. Actually I'm a lousy pilot anyway so even if I did read them I wouldn't know if they're right.

http://www.palosrc.com/instructors/trim-chrt.htm

http://www.dubai*********.org/aeroba...ming_chart.htm

Thanks.