On the reverse side of my Airframe and Powerplant certificate it says among other things the following: . .. . REPAIRMAN OPERATIONAL RESTRICTION. .. .The holder hereof shall not perform or approve alterations, repairs or inspections of aircraft accept in accordance with the applicable airworthiness requirements of the federal aviation regulations or such method, techniques and practices found acceptable to the administration.. .. .If a mechanic did otherwise, and an aircraft crashes, and it is determined that an illegal procedure was performed the mechanic can be held liable. He can be fined around $10,000 by the government and be held culpable in any legal action taken by the survivors of those killed or injured in the crash. He will also lose his ticket.