On March 22, 2024, about 1804 Pacific daylight time, a Piper PA-28-140, N1695H, was substantially damaged when it was involved in an accident near Acton, California. The private pilot applicant and designated pilot examiner were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 flight test. According to statements from the DPE and private pilot applicant, they were conducting the flight portion of a private pilot practical test. The DPE announced a simulated engine failure and reduced the engine power to idle. The private pilot applicant turned on the carburetor heat and performed the simulated emergency procedures for an engine failure. At approximately 800 ft agl the DPE instructed the applicant to go around, ending the simulated emergency. The applicant increased the engine power by advancing the throttle full forward, turning the carburetor heat off, and pitching the airplane for an indicated airspeed of 66 knots. After about 10 seconds, the applicant stated to the DPE that the airplane would not climb. The DPE confirmed that the throttle control was set to full power, mixture control was set to full rich, carburetor heat control was set to off, and that the flaps were up. He noticed that the tachometer indicated about 2000 rpm. The DPE took control of the airplane and attempted to turn away from rising terrain; however, the airplane would not maintain altitude in a turn. The DPE continued straight ahead and determined that the airplane would not outclimb the surrounding terrain, then prepared to make an emergency landing. The DPE initiated a landing along a ridgeline about 1 mile south of the go around initiation point. During the landing, the airplane impacted vegetation and came to rest upright. It sustained substantial damage to both wings, the fuselage, and the stabilator. Postaccident examination of the airframe revealed limited function of the heat door within the airbox. The carburetor heat control arm traveled from stop to stop; however, the heat door only exhibited about half its designed travel. It traveled from the carburetor heat ON position to halfway between carburetor heat OFF and ON. The carburetor heat control cable was looped around the attachment bolt and found to be loose; it was not threaded through the attachment bolt, and no safety wire was observed. The carburetor heat control knob inside the cabin traveled without binding but exhibited limited travel and was found to travel between the “Carburetor Heat OFF” position and about halfway to the “Carburetor Heat ON” position. A postaccident test run of the engine was conducted and revealed that it produced full power and showed no anomalies that would have precluded normal operation. Accident flight data from the airplane’s Garmin G5 was downloaded and indicated that the simulated emergency descent was flown toward agricultural fields, and rising terrain. Recovery from the simulated engine failure began at approximately 90 ft agl, and the airplane achieved an average rate of climb of 310 fpm from the exercise’s go-around point to the accident site. The geographical change in elevation from the go-around point to the accident site was +381 ft and the lateral distance was about one mile. According to maintenance records, the most recent annual inspection was completed on April 14, 2023, and the most recent maintenance logbook entry related to the travel of carburetor heat controls, was March 11, 2024.