On March 5, 2020, about 1422 eastern daylight time, a Piper PA-23-250, N335W, was substantially damaged when it was involved in an accident near Stanley County Airport (VUJ), Albermarle, North Carolina. The airline transport pilot and pilot receiving instruction were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. According to a Federal Aviation Administration (FAA) inspector, the owner of the airplane was not onboard during the accident flight but was taking a video recording of the accident takeoff. The owner did not possess a multiengine land rating. The owner's flight instructor was seated in the left seat, receiving a "check out" in the make and model airplane from the pilot-in-command (PIC) flight instructor seated in the right seat. After the "check out," the owner's flight instructor could then provide training to the owner. The accident flight was the first flight after an annual inspection was completed on the airplane. Additionally, the airplane was completely fueled prior to the accident flight. According to the PIC, during initial climb, about 200 ft above ground level, the pilot receiving instruction was the pilot flying. The PIC noticed a decrease in airspeed and the pilot receiving instruction stated that the engines were losing power. The PIC immediately made sure the mixture levers were full rich, and the propeller and manifold levers were full forward. He also switched on the electric fuel pumps, which had not been turned on prior to takeoff. The PIC further stated that the electric fuel pump switches were on the far left of the instrument panel and he was unable to see their position prior to the loss of engine power. The PIC added that he believed that was the mistake that caused the dual loss of engine power. The PIC then coached the pilot receiving instruction to push forward on the yoke to retain airspeed; however, the airplane was too fast to land back on the remaining runway. The engines never fully recovered power and they climbed over trees at the end of the runway before making a hard landing in a muddy field. Examination of the accident site by the FAA inspector revealed that during impact with the field, the airplane slid for about 190 ft. The left main landing gear separated and the nose gear collapsed, followed by the airplane rotating 180° before coming to rest upright. The inspector observed damage to the left wing spar, left wheel well, nose wheel well, and lower fuselage. Review of a copy of the video corroborated the pilots' statements. Further examination of the engines was performed by an independent mechanic. The top spark plugs were removed from both engines and no anomalies were observed with their electrodes. The crankshaft was rotated by hand on both engines and valve train continuity was confirmed to the rear accessory section. Additionally, thumb compression was attained on all cylinders. Examination of the induction systems did not reveal any blockages or obstructions. Eight-ounce fuel samples were obtained from each of the four fuel cells as well as the left and right engine fuel sumps. All samples were noted to be blue in color and no water or debris were detected in any of the six samples. The magnetos were removed from both engines and rotated at 420 rpm for 10 seconds. All four magnetos produced spark at all leads. The left and right engine mechanical fuel pumps were then removed and forwarded to a facility for testing. Both pumps tested satisfactorily within specifications. Review of checklists in an owner's manual and airplane flight manual for the make and model airplane revealed instructions in both to turn the electric fuel pumps on prior to takeoff.