what does a & p mechanic stand for
Aircraft maintenance technician In the USA, for a person who holds a mechanic certificate issued by the Federal Aviation Administration; the rules for certification, and for certificate-holders, are detailed in Subpart D of Part 65 of the Federal Aviation Regulations (FARs), which are part of Title 14 of the Code of Federal Regulations.[1] The US licensed qualification is sometimes referred to by the FAA as the Aviation Maintenance Technician and is commonly referred to as the Airframe and Powerplant (A&P).
Lock, stock, and barrel In the early days of firearms manufacturing, individual craftsmen made individual components one at a time. One craftsman made the "lock" which would have been a "match lock", "wheel lock", "flint lock" etc. The next craftsman made the barrel, and the last craftsman, who was a woodworker made the stock. At some point, a craftsman or a merchant started advertising "Lock Stock and Barrel" meaning that you could get your entire gun at one location and did not have to go from craftsman to craftsman to get it finished.