SR20
Flight Crew Commercial; Flight Crew Flight Instructor
Aircraft Equipment Problem Critical
Flight Crew Landed As Precaution; Flight Crew Returned To Departure Airport
Aircraft
During an RNAV XX approach into ZZZ; we experienced abnormal engine vibrations between 50-60% power. We set the power to 55% to maintain 110 as specified on the approach and immediately noticed excessive vibration coming from the engine. IP [Instructor Pilot] increased power to 65% and vibrations went away. IP then went back to 55% power and left it for a few seconds and the vibrations began to cause the screens to shake making it hard but not impossible to read. IP then returned to 65% power for the remainder of the approach and vibrations stopped. IP and PUI (Pilot Under Instruction) both agreed to discontinue the flight upon completion of the approach and notified Tower that we were going to be a full stop landing. We only reduced power again upon reaching Final Approach Fix [for] ZZZ; we set 25%; passing through the 50-60% range it started abnormal vibrating again. We landed without incident; taxied off the runway and set 1000 rpm and it started abnormally vibrating again. Aircraft was written up for maintenance to check it out.
SR20 flight instructor reported engine vibrations during approach on a training flight.