Accident Details
On February 6, 2018, at approximately 1715 central standard time, a Piper PA-34-220T twin-engine airplane, registration N9148B, was substantially damaged during a forced landing following a dual loss of engine power near Patterson, Louisiana. The pilot, a pilot-rated passenger, and one passenger were not injured. A second passenger sustained serious injuries. The airplane was operated by Air Reldan Inc. as a Title 14 Code of Federal Regulations Part 91 aerial observation (photography) flight. Day visual meteorological conditions prevailed, and the flight operated under a visual flight rules flight plan. The flight originated from South Lafourche Leonard Miller Jr. Airport (GAO), Galliano, Louisiana, at about 1347, and was destined for Harry P. Williams Memorial Airport (PTN), Patterson, Louisiana.
Flight History
The pilot reported completing a preflight inspection before departing from the operator's base at St. Tammany Regional Airport (L31). Fuel was visible in each tank at the bottom of the sidewall, and the fuel gauges indicated about 45 gallons per tank. The 30-minute flight to GAO to pick up the passengers was uneventful. The purpose of the accident flight was to photograph an oil rig located in the Gulf of Mexico about 185 miles southwest of GAO. At the passengers' request, the aft cabin door was removed to facilitate photography, which limited the airspeed to 130 knots. At that time, the fuel gauges indicated about 40 gallons per tank.
The flight arrived at the oil rig about 1 hour 20 minutes after takeoff, and the pilot circled for about 30 minutes. After photography was complete, the pilot established a return course with an estimated en route time of 1 hour 2 minutes. The fuel gauges then indicated about 10 gallons in each tank. Concerned about the fuel quantity, the pilot leaned the engine mixtures as much as possible and visually examined the airplane; no fuel leak was observed. He elected to divert to PTN as the best option given the low fuel situation. The right engine subsequently lost power about 24 miles from PTN, and the left engine lost power several minutes later. The pilot executed a forced landing to a canal adjacent to the Atchafalaya River.
One passenger stated that the pilot had informed him the airplane had not been topped off but that sufficient fuel was onboard. The passenger used a GPS tracking application that geotagged photos taken during the flight. According to the application, the flight departed GAO at 1347, arrived at the oil rig at 1514, completed photography at 1607, and diverted to PTN at 1628. The first engine lost power about 1708, followed by the second engine at about 1715.
Post-Accident Examination
A Federal Aviation Administration inspector reported that the airplane came to rest in shallow water. A post-recovery examination revealed no anomalies that would have contributed to a loss of engine power. Recovery personnel stated that no fuel sheen was observed on the water, no fuel was seen in the fuel tanks, and no fuel was observed during the recovery process. Based on hour meter readings, the total flight time from dispatch at L31 until the accident was 3.8 hours. The airplane owner noted that the hour meter ran only when the landing gear was retracted and did not record engine run time with the gear extended. The Pilot's Operating Handbook specified a fuel flow of about 10 gallons per hour per engine at economy cruise power and a maximum permitted airspeed of 129 knots with the aft doors removed. The handbook also stated that cruise performance would be reduced by approximately 5 percent when operated with the rear cabin and cargo doors removed.