Aircraft Maintenance Technician reported installation of a used engine cylinder without proper paperwork.
Synopsis
Aircraft Maintenance Technician reported installation of a used engine cylinder without proper paperwork.
Narrative
CFI was instructing a student doing slow flight when the engine started to run rough.CFI requested priority landing and the aircraft land without incident and was taxied to the maintenance hangar. On inspecting the engine; it was discovered that there was a crack in the #4 cylinder. I assisted in replacing the cylinder with what I assumed was an overhauled unit.Engine was ran up with no problems. After I left for the day; the A&P who was doing the sign off asked a private pilot to do a return to service test flight the following morning which was done with no incident. While the flight was being conducted 2 inspectors from the FSDO came by and asked to see the cracked cylinder and the paper work on the replacement cylinder. I then discovered the it was a used cylinder with no paper work.The aircraft later that day had the cylinder in question removed and replaced with a factory new cylinder with proper paper work (8130-3).Although I was only assisting with the repair; I should have checked for proper paper work be any installing the cylinder; something I will be sure to do in the future.
Second reporter narrative
While on an instructional flight; the pilot reported a rough engine & the Tower gave them priority for landing. Inspection of the engine revealed a crack on Cylinder #4. We had a serviceable cylinder and proceeded to change it. By XA00hrs we were finished. I then realized; I did not have my keys for the office; which was locked; and I decided to write out the return to service and slipped it in the maintenance status book that we keep in the aircraft.The next morning; one of our mechanic apprentices; who is a pilot came in; and I told him the plane was good for a test flight. After the test flight; the local FSDO was there to inspect the aircraft and noticed some oil in the cowling. Not being there; I told them to change it; thinking we did something wrong. A new cylinder was installed; run up; satisfactory. I took the hand written sign off and stapled it in office maintenance log; before entering the sign off for the second cylinder. The oil leak ended up being a loose clamp on the inside rear oil return hose.The local FSDO; I assume; thinks the plane flew; without a maintenance release; since the inspectors came to our office and took photos of our log books. The sign off was in the plane; that left the hanger 10 minutes before they arrived unannounced.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.