On June 8, 2017, about 1340 mountain daylight time, a Bellanca 17-30 airplane, N7328V, made an forced landing in a field near Front Range Airport (FTG), Watkins, CO. The commercial rated pilot and passenger sustained serious injuries and the airplane sustained substantial damage. The airplane was registered to and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed at the time of the accident and no flight plan had been filed. The local flight originated from FTG at an unknown time. The pilot reported that he and the passenger planned to conduct touch-and-go landings at FTG. He added that the main fuel tanks were full before takeoff and he began the flight with the left fuel tank selected. After performing an unknown number of landings, he reportedly switched from the left to the right fuel tank, while in the traffic pattern. He completed one more touch-and-go landing and the engine experienced a loss of power on the on the upwind leg of the traffic pattern. The engine did not show signs of a problem before the loss of power and the fuel gauge indicated full during the entire flight. He reportedly switched back to the left tank and was unable to restart the engine. During the forced landing the airplane impacted a ditch and came to rest upright (figure 1). Figure 1 – Accident airplane The passenger stated to the police that the airplane was at 6,100 ft above mean sea level (700 ft above ground level) when the loss of engine power occurred, and that they "were too low to troubleshoot the problem." The airplane owner reported that he and his wife flew the accident airplane on June 7, 2017 for about 1 hour, during which time the engine performed normally with no anomalies noted. He reportedly told the pilot that he would need to top off the fuel tanks before the next flight because fuel had not been added after the last 2.5 flight hours. He was unaware of any fuel being added to the tanks after this flight and before the accident flight. There were no fuel receipts discovered during the investigation. A postaccident examination of the airplane by the responding Federal Aviation Administration inspector revealed damage to the airplane's firewall. The fuel selector was positioned to left main fuel tank. The two auxiliary tanks contained fuel to the top of the tanks at the fuel filler port. The right wing was slightly elevated at the accident sight and an undetermined about of fuel was clearly visible from the right main fuel tank filler port. During the recovery process, left main fuel tank was empty and the other 3 fuel tanks contained about 45 gallons of fuel combined. The airplane owner reported that the pilot had accumulated over two hours of flight time in the accident airplane prior to the accident flight. The owner added that he and the pilot received informal training on the airplane systems and fuel management in February and a refresher on fuel management two weeks before the accident. The pilot reported 3.4 total hours in the accident airplane type. The postaccident examination and engine functional test was performed under the supervision of the FAA. Before the functional test began, a replacement propeller was installed, and an external fuel tank was connected to the engine fuel line. The airplane's electrical power was turned on, but the electric boost pump did not operate. After several unsuccessful attempts to start the engine without priming the fuel system a replacement electric boost pump was installed into the external fuel tank. The replacement boost pump was only necessary for engine start and not needed for engine operation after it started. Then, the fuel system was bled, primed and started on the first attempt. The engine was operated at 1,500 rpm until it was warm. The engine would not operate below 1,500 rpm due to impact damage to the throttle cable end. Then the throttle was advanced to yield 2,100 rpm with no anomalies noted. After about 2 minutes the throttle was advanced full forward and the engine operated at 2,800 rpm; after a couple of seconds the propeller governor reduced the engine to 2,600 rpm. After running the engine for about 1 minute the mixture control was pulled to idle-cutoff and the engine was stopped. After the engine functional test, the fuel selector valves were tested by blowing compressed air into the fuel tank outlets and air was observed coming out of the engine driven fuel pump inlet line. Both fuel selectors operated normally and there were no blockages noted within the fuel lines. The examination did not reveal any preimpact anomalies that would have precluded normal operation.