C172 instructor pilot reported while on a training flight the aircraft engine malfunctioned.

Attributes
ACN	1759556
Time
Date	202009
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Tower
State Reference	US
Environment
Light	Daylight
Aircraft 1
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	None
Component
Aircraft Component	Engine
Person 1
Function	Instructor
Qualification	Flight Crew Commercial Flight Crew Flight Instructor
Experience	Flight Crew Last 90 Days 70 Flight Crew Total 640 Flight Crew Type 400
Events
Anomaly	Aircraft Equipment Problem Critical

Narrative:

Carb heat was pulled on and power reduced to idle by the instructor for a simulated engine failure for training around 4;000 feet MSL. After the student ran through the checklist for the practice maneuver; the instructor told the student to clear the engine. Upon attempted clearing of the engine; it sputtered and the instructor took control. Full power was not restored. The pilot called tower and advised of a possible [priority] landing. The instructor completed a safe and controlled landing in a field. There was no visible damage to the airplane and no injuries.

Original NASA ASRS Text

Title: C172 Instructor Pilot reported while on a training flight the aircraft engine malfunctioned.

Narrative: Carb heat was pulled on and power reduced to idle by the instructor for a simulated engine failure for training around 4;000 feet MSL. After the student ran through the checklist for the practice maneuver; the Instructor told the student to clear the engine. Upon attempted clearing of the engine; it sputtered and the instructor took control. Full power was not restored. The pilot called Tower and advised of a possible [priority] landing. The Instructor completed a safe and controlled landing in a field. There was no visible damage to the airplane and no injuries.

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.