Skyhawk 172/Cutlass 172
Flight Crew Flight Instructor
Situational Awareness
Aircraft Equipment Problem Critical
Aircraft
During the event; the aircraft experienced engine roughness 2 times. One of them being while recovering from stall and adding full power; RPM dropped and engine started to sound as if was going to fail. The second time was when we were approaching ZZZ for a full stop; starting the ZZZZZ Arrival; the engine exhibit the same roughness.
C-172 Flight Instructor experienced engine roughness in flight.