MOONEY AIRCRAFT CORP. M20K — Hanna City, IL

What happened

The pilot had flown about 4.8 hours and was about 10 miles from the destination airport when he reported to air traffic control that the engine lost all power and that he was not going to be able to reach the destination airport. A review of automatic dependent surveillance-broadcast (ADS-B) data showed the airplane aligned with a road with the last data point about 675 ft above mean sea level (msl).

Surveillance video footage captured the airplane near the last ADS-B data point. In the video, the landing gear was extended, and the propeller appeared to be windmilling. As the airplane descended, it struck powerlines. A second video taken from inside a vehicle showed the airplane immediately after the powerline contact. The airplane continued the descent and touched down on the roadway. After touchdown, the left wing impacted a bridge railing, a road sign, and a power pole, which separated the left wing. The remainder of the airplane impacted a building, which resulted in substantial damage to the fuselage.

A postaccident examination revealed that the left-wing fuel tank was breached during the impact and absent of fuel. The right-wing fuel tank remained intact, and only a small amount of fuel was present inside the tank. The fuel selector was positioned on the “RIGHT TANK.” The fuel strainer contained about 3 oz of fuel and the fuel line into the fuel flow divider was absent of fuel. No mechanical malfunctions or failures were discovered with the airframe or engine that would have precluded normal operation. The airplane was equipped with a fuel-injected engine and, as such, was not susceptible to carburetor icing.

Although the pilot added 54 gallons of fuel the day before the accident, the exact amount of fuel onboard at the time of departure could not be determined. A review of airplane performance charts and wind aloft observations revealed that if the flight had departed with just the 54 gallons, the endurance would have been between 3.7 and 4.7 hours. Had the airplane departed with full fuel tanks (75.6 usable gallons), the endurance would have been between 5.4 and 6.8 hours. These calculations do not include additional fuel required to climb to altitude.

Based upon the lack of fuel in the fuel lines, flow divider, and right wing fuel tank, it is likely the engine lost power due to fuel exhaustion.

Toxicology testing revealed that the pilot had used cannabis as low concentrations of its inactive metabolite THC-COOH were detected in his heart blood and urine. The active, short-lived metabolite of THC, 11-OH-THC was detected in his urine, but not in his blood. While the pilot’s pattern of cannabis use is unknown, given the lack of psychoactive THC in his blood and low concentration of 11-OH-THC and THC-COOH in his urine, it is unlikely that the pilot was under the influence of THC. Thus, while the pilot was found to have cannabis in his body, the effects of the pilot’s use of cannabis did not contribute to this accident.

An editorial "what led to it / how to avoid it" analysis for this accident is generated separately and will appear here.