Primary finding
Probable cause
Fuel starvation to the left engine and the resulting loss of engine power to that engine, and a loss of airplane control due to the pilot's failure to maintain the minimum controllable airspeed.
Investigator assessment
Analysis narrative
The commercial pilot was conducting an aerial observation (surveying) flight in a piston engine-equipped multiengine airplane. Several hours into the flight, the pilot advised air traffic control (ATC) that the airplane had a fuel problem and that he needed to return to the departure airport. When the airplane was 8 miles from the airport, and after passing several other airports, the pilot informed ATC that he was unsure if the airplane could reach the airport. The final minutes of radar data depicted the airplane in a descent and tracking toward a golf fairway as the airplane's groundspeed decreased to a speed near the single engine minimum control airspeed. According to witnesses, they heard an engine sputter before making two loud "back-fire" sounds. One witness reported that, after the engine sputtered, the airplane "was on its left side flying crooked." Additional witnesses reported that the airplane turned to the left before it "nose-dived" into a neighborhood, impacting a tree and private residence before coming to rest in the backyard of the residence. A witness approached the wreckage immediately after the accident and observed a small flame rising from the area of the left engine. Video recorded on the witness' mobile phone several minutes later showed the airplane engulfed in flames. Examination of the wreckage revealed no evidence of any preimpact mechanical malfunctions or failures of either engine. The fuel systems feeding both engines were damaged by impact forces but the examined components generally displayed that only trace amounts of fuel remained; with the exception of the left engine nacelle fuel tank. Given the extent of the fire damage to this area of the wreckage, and the witness report that the post impact fire originated in this area, it is likely that this tank contained fuel. By design, this fuel in this tank was not able to supply fuel directly to either engine, but instead relied on an electric pump to transfer fuel into the left main fuel tank. Fire damage precluded a detailed postaccident examination or functional testing of the left nacelle fuel transfer pump. Other pilots who flew similar airplanes for the operator, along with a review of maintenance records for those airplanes, revealed at least three instances of these pumps failing in the months surrounding the accident. The other pilots also reported varying methods of utilizing fuel and monitoring fuel transfers of fuel from the nacelle fuel tanks, since there was no direct indication of the quantity of fuel available in the tank. These methods were not standardized between pilots within the company and relied on their monitoring the quantity of fuel in the main fuel tanks in order to ensure that the fuel transfer was occurring. Had the pilot not activated this pump, or had this pump failed during the flight, it would have rendered the fuel in the tank inaccessible. Given this information it is likely that the fuel supply available to the airplane's left engine was exhausted, and that the engine subsequently lost power due to fuel starvation. The accident pilot, along with another company pilot, identified fuel leaking from the airplane's left wing, about a week before the accident. Maintenance records showed no actions had been completed to the address the fuel leak. Due to damage sustained during the accident, the origin of the fuel leak could not be determined, nor could it be determined whether the fuel leak contributed to the fuel starvation and eventual inflight loss of power to the left engine. Because the left engine stopped producing power, the pilot would have needed to configure the airplane for single-engine flight; however, examination of the left engine's propeller found that it was not feathered. With the propeller in this state, the pilot's ability to maintain control the airplane would have been reduced, and it is likely that the pilot allowed the airplane's airspeed to decrease below the single-engine minimum controllable airspeed, which resulted in a loss of control and led to the airplane's roll to the left and rapid descent toward the terrain. Toxicology results revealed that the pilot had taken doxylamine, an over-the-counter antihistamine that can decrease alertness and impair performance of potentially hazardous tasks. Although the toxicology results indicated that the amount of doxylamine in the pilot's cavity blood was within the lower therapeutic range, review of ATC records revealed that the pilot was alert and that he was making necessary decisions and following instructions. Thus, the pilot's use of doxylamine was not likely a factor in the accident.
Source record
Factual narrative
HISTORY OF FLIGHT On March 12, 2019, at 1516 eastern daylight time, a Piper PA-31-350, N400JM, was substantially damaged when it impacted terrain in Madeira, Ohio. The commercial pilot was fatally injured. The airplane was operated by Marc, Inc. under the provisions of Title 14 Code of Federal Regulations Part 91 as a commercial aerial observation flight. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight that originated from Cincinnati Municipal Airport-Lunken Field (LUK), Cincinnati, Ohio, at 1051. Federal Aviation Administration (FAA) radar data revealed that, after departure LUK, the airplane flew several survey tracks near Cincinnati, Ohio, before proceeding north to fly survey tracks near Dayton, Ohio. According to air traffic control (ATC) voice communications, the pilot contacted ATC at 1503 to request direct routing to LUK due to a fuel problem. The air traffic controller advised the pilot to proceed as requested and offered Dayton-Wright Brothers Airport (MGY), which was 8 miles ahead, as a landing alternative. The pilot responded that he had MGY in sight but wanted to continue to LUK, which was 30 miles away. The controller then asked the pilot if he wanted to declare an emergency, and the pilot responded "negative." About 1505, when the airplane was at 5,000 ft mean sea level (msl), the controller asked the pilot if he required any assistance with the fuel issue, and the pilot responded that he should be "okay." The controller then advised the pilot that "multiple airports" were available between his location and LUK, and the pilot informed the controller that he would advise if the fuel issue developed again. About 1513, the pilot established radio contact with the LUK ATC tower and advised the controller that the airplane had a fuel problem and that he was hoping to reach the airport. At that time, the airplane was at an altitude of 1,850 ft msl and was about 8 miles north of LUK. Shortly thereafter, the pilot advised the controller that he was unsure if the airplane would reach the airport. No further communications were received from the pilot. Radar data showed that, between 1513 and 1516, the ground track of the airplane was about 200°, the airplane descended to an altitude of 1,275 ft msl, and its estimated groundspeed decreased from about 140 to 98 knots. At 1516, the radar data depicted a right turn to a heading of about 250° and a ground track that aligned with a golf course fairway (which had an elevation of 865 ft msl). At 1516:27, radar data indicated that the airplane was about 180 ft from the fairway at an altitude of 1,050 ft msl and an estimated groundspeed of about 82 knots. The airplane's last radar-recorded position was located about 550 feet from the accident site. No additional radar data were recorded. According to witnesses, the airplane engine sputtered before making two loud "pop" or "back-fire" sounds. One witness reported that, after sputtering, the airplane "was on its left side flying crooked." Another witness reported that the "unusual banking" made the airplane appear to be flying "like a 'stunt' in an air show." Two additional witnesses reported that the airplane was flying low when it turned to the left and "nose-dived" into their neighborhood. The airplane then impacted a tree and the backyard of a residence. A witness from an adjacent residence heard the impact, approached the wreckage immediately after the accident, and noted a "whitish gray smoke coming from the left engine." He reported that "a small flame began rising from that same area." Video recorded on the witness' mobile phone about 1522 showed the area around the left engine engulfed in flames. The witness stated that the airplane was fully engulfed in flames about 3 minutes later. PERSONNEL INFORMATION According to FAA records, the pilot held a commercial pilot certificate with ratings for airplane single-engine land, airplane multi-engine land, and instrument airplane. He also held a flight instructor certificate with ratings for airplane single-engine, and instrument airplane, and a ground instructor certificate. His most recent FAA first-class medical certificate was issued November 8, 2018. According to the operator (Marc, Inc.), the pilot was contracted to work for them about 1 month before the accident. Examination of the pilot's logbook revealed that as of February 19, 2019, he had accrued 6,392 total hours of flight experience. The logbook included seven entries for Marc, Inc., all of which were in the Cessna 310. The pilot had logged 1,364 hours of flight time in the accident airplane make and model, all of which had been accumulated prior to 2010. The logbook also showed no piston multiengine airplane flight time between that time and his employment with the operator; all of the pilot's logged flights during that time were in turbine and/or single-engine airplanes. The available evidence did not indicate if the pilot received any training or a flight check in the PA-31-350. Review of daily flight logs submitted to the company showed that the pilot flew the accident airplane for 2.5 hours the day prior to the accident. AIRCRAFT INFORMATION A review of the airplane's maintenance logs revealed that the airplane's most recent annual inspection was completed on July 1, 2018, at 19,094 total hours of operation. The left engine had accumulated 453.5 hours of operation since its most recent inspection and 2,991.5 hours of operation since overhaul. The right engine had accumulated 448.5 hours since its last inspection. The time since overhaul for the right engine could not be determined based on the information contained within the logs. Additionally, several entries logging maintenance had been added to the records as loose, unbound sheets; several entries within the logs documented maintenance that had been performed to other airplanes; and the right propeller logbook documented maintenance to a propeller whose serial number did not match the propeller installed on the accident airplane's right engine. A company pilot reported that the accident airplane had a fuel leak in the left wing and provided a photograph of the fuel on the hangar floor, taken about a week before the accident. The company pilot also reported that the accident airplane was due to be exchanged with another company PA-31-350 the week before the accident so that the fuel leak could be isolated and repaired but that the airplane remained parked for a few days and was not exchanged. The accident pilot was then assigned to fly the airplane. One of the pilot's relatives reported that the pilot told him that the accident airplane had airplane fuel leak about 1 week before the accident. Review of the maintenance records revealed no entries in the 2 weeks preceding the accident. The accident airplane was flown by another company pilot about 1 month before the accident, and he had to perform an unscheduled single-engine landing at Smyrna Airport (MQY), Smyrna, Tennessee, The pilot stated that he secured the right engine after an indication of low oil pressure and that maintenance work to address "external oil leaks" was performed at a fixed-base operator at MQY. Review of the airplane's maintenance records revealed no entries associated any repairs following this event. The company owner/manager stated that he knew "of no single engine landings" involving the accident airplane. Fuel System Each wing contained an inboard (main) and an outboard (auxiliary) fuel tank, which were standard components. Fuel for each engine was routed from either the main or auxiliary fuel tank to the selector valve, fuel filter, fuel boost pump, emergency fuel pump, firewall shutoff, engine-driven fuel pump, and fuel injectors. The engine-driven fuel pumps ran continuously and were not controllable by the pilot. Two electric fuel quantity gauges indicated the fuel quantity in the respective (left or right w