Narrative:

While doing a CFI spin flight; the student was in the middle of climbing out of a spin recovery when the engine popped and began to vibrate severely. Instructor had the student level off and reduce the throttle and then asked if the student felt the vibration; too. Student said yes and that the yoke was vibrating severely as well. Instructor and student made the decision to return back to ZZZ.

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Original NASA ASRS Text

Title: C172 flight instructor reported a significant engine vibration and elected to return to the departure airport.

Narrative: While doing a CFI spin flight; the student was in the middle of climbing out of a spin recovery when the engine popped and began to vibrate severely. Instructor had the student level off and reduce the throttle and then asked if the student felt the vibration; too. Student said yes and that the yoke was vibrating severely as well. Instructor and Student made the decision to return back to ZZZ.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.