On December 5, 2017, about 1835 mountain standard time, a Piper PA-34-200T, N47536, was substantially damaged when it was involved in an accident near Glendale, Arizona. The flight instructor and the commercial pilot were not injured. The airplane was as a Title 14 Code of Federal Regulations Part 91 personal flight. The instructor reported that the commercial pilot receiving instruction, who was flying the airplane, successfully completed two simulated engine failure maneuvers in the traffic pattern. During the third traffic pattern, the instructor initiated a right engine failure. While on base, the pilot extended the landing gear and verbally confirmed that all three landing gear lights were green, which indicated the landing gear were down and locked. Upon touchdown, the left wing "dipped" and the airplane bounced back into the air. The instructor took the flight controls and, in an attempt to climb, applied full power to both engines; however, the nose of the airplane dropped, and the airplane started to drift toward the left side of the runway. The instructor determined that the airplane would not climb, and he retarded both throttle and mixture controls and attempted to maintain directional control while simultaneously applying brakes to stop. The airplane departed the left side of the runway and came to a complete stop in the adjacent dirt area. The instructor also reported that "the left landing gear malfunctioned" upon touchdown. Examination of the accident site revealed that the airplane landed with all three-landing gear extended; each tire's skid mark was visible on the runway surface to the left of the centerline. Additionally, the landing gear imprints were visible in the dirt where the airplane veered off the runway. The runway edge light and the 1,000-ft distance marker showed evidence of the left propeller/nose impacts. The left main landing gear collapsed after it impacted the distance marker, as evidenced by wide tire marks as the airplane started to roll on the sidewall of the left tire. Examination of the left main landing gear fracture surface revealed slant fractures consistent with an overstress failure. One small area of the fracture surface, coincident with the forging flash line, exhibited a flat fracture surface. A sample that contained the flat fracture area was further examined under the scanning electron microscope, which revealed striations consistent with a fatigue fracture.