In a previous thread I was discussing modifications to my Avistar by adding the speed brakes from the Hobbico Nextstar trainer.

[link=http://www.rcuniverse.com/forum/m_1581225/mpage_1/key_avistar%252Cmodifications/anchor/tm.htm#1581225]Avistar with Nextar Modifications[/link]

They worked very well at shaving speed off the Avistar. I can make a landing approach at half of the speed from before. It also greatly reduces the speed of this airplane by 50% mainly because you can’t fly it over half throttle without it ballooning upwards. I knew this would be the case before I added the static flaps. They are great for practicing touch-in-goes.

However there is a small side effect that can be a problem. The plane will stall at really slow speed so you have to keep it above idle or you will lose lift. It really helps for gentle landings.

Someone recommended using an 11x 4 prop. This was not a good combination with these speed flaps. If you plan to do this, use a standard 10 x 6 prop. I lost way too much thrust with the 11 x 4 prop and my engine kept loading and I couldn’t get all the power I needed from the engine and I almost crashed recovering from a stall.