Randy The 51% rule only applies to the actual construction of the kit or aircraft in question. It is what separates a factory built aircraft kit from an amateur built kit.
The rules concerning being approved for repairman certificate are left more on the judgement of the Airworthiness Representative who is conducting the inspection at the time the certificate is issued. If the aircraft were complete when purchased but never signed off, and say had been badly stored, so that the new owner had to perform a great deal of repair work and replacement of assemblies/rebuild, the DAR or FAA Rep could feel that he has enough intimate knowledge of the airplane to be awarded a repairman's certificate. I bought mine with 20 hours of engine running and taxi testing but no flight time, and no certificate. I built a new seat for it, installed new lights, radio, transponder, and several other instruments to make it legal for Day and Night VFR, as well as a little bit safer and more comfortable, like GPS, and a new pushtube control for the elevator, and dual sticks. Although the DAR really liked the changes and felt I had done a good job, he didn't award me repairman certification because I had not constructed enough of the original airplane to conduct my own annual condition inspection. He explained that that did not stop me from repairing and then test flying the aircraft, but once a year I have to have another DAR or A&P look over the plane and give it its condition inspection. A small compromise in the scheme of things. Colin N96TA Ormond Beach, FL
