My friend built a Comp Arf Bae Hawk as per the plans and instructons. Powered by a Jercat P 120 and with quailty radio and equipment. He has double and triple checked the CG and has it set at 7 7/8". I have the priveledge of being the guy who does his intitial flights and I assist him it getting the throws and rates and trims setup.

Here is what I have noted about the way this airplane flies that is to me unusual and somewhat troublesome. This airplane is EXTREMELY pitch sensitive to changes in power and airspeed. For example : I trimmed the airplane to flight straight and level hands off at half or 2/3 throttle, then, if the throttle is advanced to full power the airplane will climb almost instantly and I dont mean a gradual climb either. I mean it will pitch up to a near straight up vertical climb. Conversely, if the throttle is cut to idle the airplane will drop the nose to a very nearly straight down attitude. Naturally any airplane will climb or descend to some extent when power is added or cut and no pitch trim is or elevator input is given. But I have never seen one like this. My initial thoughts were that we had a major thrust angle problem but he has checked and tweaked the engine angle and it is now correctly lined up as far as being parallel to the tail pipe but still the pitchy issues persist to more or less the same degree. Now this is not to say that the elevator ( or in this case flying stab) lacks the authority to overcome these issues because it absolulely does. The airplane files quite smoothly and well except for this. I have learned to overcome the pitches up and down with elevator inputs and or trim inputs but I have seldom if ever seen a plane that requires such massive trim changes with speed and power changes in order to fly level hands off.

I tend to think that it is nose heavy to some extent but I cant imagine that moving the CG back wll solve this or make it reasonably tolerable even.

This airplane has a farily small wing and therfore a pretty high wing loading but its not an X-15 or F 104 either. He had also read somewhere that some guys were flying these with both ailerons raised ( to what extent he couldnt recall).

I want to add more tail weight at this point, he wants to set up a mix with throttle being the master and elev the slave. Add more power and get more down elev automatically and vice versa. I am not sure this is a good idea or the proper thing to try at this time.

I am interested in hearing any and all suggestions, especially from other pilots who have owned and or flown this airplane.