I sold an airframe to a buyer nearly 6 months ago, he is just now raising an issue about the airframe. Claiming now I knowingly sold him a faulty product. What are my rights and his rights. I never would have sold him this airframe if there was a problem. His emails are basically saying he wants his money back. 6 months later. What should I do or expect.

If you knowingly sold him a faulty airframe, own up to it and make it right.

On the other hand if he noticed a problem during his first flight that you didn't realize was there you may want to help him split the cost of a new airframe. However, if he's flown it several times over the last 6 months I don't see an obligation on your part to do anything. We all know it only takes one flight to make a good airplane go away.

Then there is the part that says caveat emptor. If you're description was accurate and he got what he paid for, there is nothing more for you to do about it.

aaflyer, get him (or her) to send you a picture of the damage part then if you have a picture of the same area then you can prove (or atleast have something backing you up) but if you did know it was there (I'm not saying you did) but go ahead and tell him, and try to work it out.