N7602YPiper PA-30 · 1964

On September 12, 2020, about 1143 mountain daylight time, a Piper PA-30 airplane, N7602Y, was substantially damaged when it was involved in an accident near Billings Logan International Airport (BIL). The airline transport pilot was seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight.

The pilot does not recall the accident; however, he recalls that he had an issue with the right engine and had to shut it down. The airplane departed Lake Elmo Airport (21D), St. Paul, Minnesota, and was destined for BIL. According to the FAA, the pilot contacted the BIL air traffic control tower asking for clearance to land on runway 28. In addition, the pilot mentioned that the airplane had one engine “out” but did not share details, nor did he declare an emergency. As the airplane was on short final, the pilot made another radio call to the tower indicating that he lost the second engine. The airplane landed short of the runway against a cliffside. On-scene law enforcement reported that they did not smell fuel at the accident site, nor was fuel present in the fuel tanks.

Postaccident examination of the airframe did not reveal any anomalies that would have precluded normal operations. Flight control continuity was established throughout. All of the fuel caps were loose in their filler necks; however, the cap seals were pliable and undamaged. No fuel was present in any of the fuel bladders. The fuel strainers were drained, and a small amount of uncontaminated fuel exited. The strainer bowls were removed, and no anomalies were noted. The fuel selector valve hands were undamaged; they moved freely by hand and exhibited normal detents. The auxiliary pumps would not operate when the switch was in the ON position. The airplane structure near the pumps exhibited extensive damage and the pumps were unable to be examined.

Examination of both engines did not reveal any anomalies that would have precluded normal operations. All upper spark plugs were removed and exhibited normal operating wear signatures. All cylinder rocker covers were removed, and the valves were lubricated with a light brown oil. The crankshaft was rotated by hand on both engines; thumb compression was obtained on all cylinders and the valves moved accordingly. In addition, spark was obtained from each ignition lead.

The right engine propeller assembly was found in the feathered position, and the spinner exhibited impact damage to one side. One blade was bent about midspan and exhibited multidirectional scuffing near its leading edge. The other propeller blade exhibited damage consistent with recovery. The left engine propeller assembly was found in the low pitch position. One blade was bent aft near the shank and exhibited scuff marks on its cambered side near the leading edge. The other blade was unremarkable.

Estimated fuel calculations were completed for full fuel tanks. The accident flight was about 4 hours and 31-minutes long. According to the Piper Twin Comanche Owner’s Handbook, the airplane’s fuel capacity is 84 gallons of usable fuel, and it would have consumed about 77.4 gallons when operated at 75% power. The calculations did not account for variables such as engine leaning, wind, climb, or descent.