Without the intention to dispute or confuse anyone here, you may want to look at the Irvine and H-9 Evolution engines. Both are excellent and less expensive than the OS. Various unbiased engine reviews support this statement.

With well more than 30 years in the hobby, I'm going to make a statement that will raise the hairs on the back of many peoples' necks. OS engines of today are nowhere near the quality and power of the engines of yesterday. The FSR and SF series of engines were the best that OS ever made, and it has been downhill since then. There are engines as good, or better, than the OS of today for less money. In any case, you don't need a ringed engine for your intended plane.

The AMA, in answer to your question, has been the primary source of ALL the radio frequencies that we use today. They also have been a major supporter of model aircraft competition. This competition has been the driving force behind the improvements of our equipment. Without the AMA, there never would have been a Tournament of Champions. The insurance provided by AMA membership is a large factor in owners of flying sites permitting the flight of model aircraft on their property. Bear in mind that insurance is not the primary purpose of the AMA.

Over the many years of the AMAs' existence, they alone have gone before our government to obtain and protect our radio frequencies, and our ability to continue this wonderful hobby. Take the time to look through the AMAs' website, "www.modelaircraft.org" and see if you can learn anything at all while you are there. If you do, that was a benefit obtained from the AMA that you did not obtain anywhere else.

Don't misunderstand me, I am not a rabid proponent of the AMA, but they have a place and purpose in this hobby, a very important one.

With knowledge comes understanding,
Silversurfer