Cessna 172 Flight Instructor reported severe engine vibration during climb. Instructor returned to departure airport.
Synopsis
Cessna 172 Flight Instructor reported severe engine vibration during climb. Instructor returned to departure airport.
Narrative
During the preflight and run up; nothing unusual was found. After takeoff from runway XXL at ZZZ; at about 1200 ft; I heard a very loud bang followed immediately by severe engine vibrations and unusual engine sounds. I was still in a normal climb just before this happened. I took the controls from my student and started turning back to ZZZ and told ATC that I needed to land immediately. The engine was still producing some power. It was stable around 2000 rpm but running extremely rough. I did reduce the throttle slightly after the initial bang to reduce the vibration. Surprisingly; the oil pressure and temperature were normal even though it was clear something went catastrophically wrong. I did not declare an emergency because the engine was still producing some power; and I did not know the extent of the damage. I did not attempt any troubleshooting to make the engine run normally because of the limited time I had to set up for approach and landing. Also; I did not think the engine was in a recoverable state due to the vibration and sounds coming from it. I landed on runway XY at ZZZ and taxied back to parking without issue. After shutting down the engine; the most obvious damage was the front right engine cylinder. It was completely broken in half and pushed out about a half inch. I believe this was the cause of the engine roughness and partial loss of power. I believe the bang I heard was from the cylinder breaking. Also; oil was coating the right side of the engine and coming out of the exhaust.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.