CEN22FA298

The inadequate maintenance of the airplane fuel system that resulted in fuel exhaustion and a loss of engine power.

The airplane was topped off with fuel on the day of the accident. The airplane was flown to an intermediate airport then back to the original departure airport. After returning to the departure airport, the pilot and a pilot-rated passenger took off to practice full-stop takeoffs and landings. They performed five uneventful takeoffs and landings; during the last takeoff climb, the airplane sustained a loss of engine power. Witnesses reported that the airplane’s right wing dropped and the airplane rotated clockwise, as viewed from above, before it impacted the ground. Postaccident examination of the airplane revealed no useable fuel in the wing’s fuel bladder tanks. Both fuel bladders were collapsed and the attachment hardware for the bladder was not properly attached to the wing. Examination of the fuel system revealed that the fuel sending units had bends on their float arms inconsistent with their design and did not meet airplane maintenance manual specifications for resistance values. Additionally, the fuel selector valve did not contain detents for the position of each fuel tank selection. Examination of the engine, engine accessories, and airframe revealed no other mechanical anomalies that would have precluded normal engine operation. The last maintenance entries that were provided, including the annual inspection, were not part of the airframe and engine logbook(s), and did not show date of maintenance, time-in-service, and signature. Investigators were unable to determine who performed the most recent maintenance of the airplane. The collapsed fuel bladder would have reduced the fuel capacity when the airplane was last serviced with fuel. The fuel sending units likely provided incorrect fuel tank indications on the fuel gauges in the cabin. The pilot likely would have performed fuel calculations based upon the designed fuel tank capacity. Both the diminished fuel bladder capacity due to the collapsed bladders and the improper fuel level indications likely led to the loss of engine power due to fuel exhaustion. The pilot had cardiomegaly with left ventricular wall thickening and moderate atherosclerosis in two coronary arteries. He also had asthma and the bronchodilator albuterol was detected in his blood in urine. While these medical conditions can result in a sudden impairing or incapacitating event, there was no evidence that this occurred. The pilot had opportunity to discontinue the flight if he felt ill, he was actively flying the airplane, and there was a pilot-rated passenger aboard who could assist. Thus, the pilot’s medical conditions were not a factor in this accident.

The 60-year-old male pilot held a second class medical certificate with the limitation that he must wear corrective lenses and possess glasses for near/intermediate vision. At his most recent Federal Aviation Administration (FAA) medical certification examination on January 19, 2022, he reported taking no medications. He had a history of hay fever and asthma. According to the autopsy report, the cause of death of the private pilot was craniocerebral, thoracic, and abdominal blunt trauma, and the manner of death was accident. The private pilot was found to have an enlarged heart (600 grams) with a left ventricular wall of 1.6 centimeters and 50% atherosclerosis in his left anterior descending and right coronary arteries. Toxicology testing detected the generally non-impairing asthma medication albuterol in the private pilot’s cavity blood and urine. The 39-year-old male pilot-rated passenger held a first class medical certificate without limitation. At the time of his most recent FAA medical certification examination on May 27, 2022, he reported no medical concerns, and no significant conditions were identified on physical examination. No specimens were obtained from the pilot-rated passenger for toxicology testing. The Piper Comanche PA-24-250 Owner’s Manual, Design Features, 1. Specifications, stated that the cruising range with 60 gallon fuel tanks, at sea level, and 75% power is 4.3 hours. Aircraft logbooks provided by the pilot’s son included a separate page that was not part of the “Aircraft Log”. The separate page did not cite the aircraft’s registration number and had only three printed entries that were not consistent in completion and format as those entries in the “Aircraft Log” and “Engine Log.” These entries did not meet requirements cited in 14 CFR Part 43.11, “Content, form, and disposition of records for inspections conducted under parts 91 and 125 and 135.411(a)(1) and 135.419 of this chapter.” The first entry on the separate page stated that an annual inspection was completed and it was signed by an airframe and powerplant mechanic with inspection authorization. The first entry had a date entry of April 12, 2022, and had blank entries for aircraft total time and tachometer time. The second entry on the separate page was for a 100-hour inspection of the engine with the pilot’s printed name and airframe and powerplant certification number; there was no signature. The second entry’s aircraft total time, tachometer, time since major overhaul, and date were blank. The third entry on the separate page was for an oil change with the pilot’s printed name and airframe and powerplant certification number; there was no signature. The third entry’s aircraft total time, tachometer, time since major overhaul, and date were blank. The pilot/owner held a mechanic’s certificate with airframe and powerplant ratings in addition to his pilot certificate and ratings. The pilot’s logbook showed entries for the completion of flight reviews in 2017, 2019, and an undated entry for the completion of a flight review. A National Transportation Safety Board Pilot/Operator Aircraft Accident/Incident form was not received from the airline-transport-pilot-rated passenger. On July 2, 2022, at 1135 central daylight time, a Piper PA-24-250, N5235P, was involved in an accident near St. Jacob, Illinois. The airplane was destroyed. The pilot rated passenger received serious injuries and the pilot was fatally injured. The airplane was operated under Title 14 Code of Federal Regulations (CFR) Part 91 as a personal flight. The private pilot/airplane owner and his son departed in the accident airplane from St Louis Metro-East Airport/Shafer Field (IL48), St Jacob, Illinois, to pick up the airline-transport-pilot-rated passenger at Eagle Creek Airpark (EYE), Indianapolis, Indiana. The pilot was to familiarize the pilot-rated passenger with the airplane so that he could later provide flight instruction to the pilot’s son. Before departure from IL48, the airplane was “topped off” with fuel by the pilot’s son, and no fuel was obtained at EYE. Before departure from EYE, an “abrupt” airplane preflight was performed and the airplane fuel system was not sumped, and the fuel level within the fuel tanks was not [visually] checked. Upon return to IL48, the pilot’s son stated that he exited the airplane and at that time the right fuel tank gauge indicated just under a ¼ tank, and the left fuel tank gauge indicated just under ½ tank; he estimated there was about 12 gallons of fuel remaining. The pilot’s son stated that after he exited the airplane, his father and the pilot-rated passenger switched seats so that the pilot-rated passenger was in the left seat and the his father was in the right seat. They then performed five normal takeoffs and full-stop landings. He heard the engine sputter on the last takeoff, the landing gear retracted, and the airplane began to climb. The airplane then rolled to the right, nosed down, and impacted the terrain. The pilot-rated passenger stated that they were “just above the treetops” when the engine lost power during climbout from the sixth takeoff. He noted that the pilot took control of the airplane and began “actions that you would undertake following engine power loss.” Although he recalls the pilot turning the airplane to the right “pretty aggressively,” he did not recall any indications of a stall, such as a stall warning horn, before the airplane quickly descended in a nose-low attitude into the ground. A witness stated that he saw the airplane make several full-stop takeoff and landings before the accident takeoff, during which the “engine started to sputter right after it lost power, in and out couple of times.” The airplane’s right wing then dropped down, and the airplane started to rotate clockwise as viewed from above. He saw the airplane descend behind a hill with a soybean field, at which time he lost sight of the airplane. The airplane impacted terrain and came to rest in an upright attitude in a field southeast of the departure end runway 13. The airplane wings, fuselage, and empennage exhibited vertical crush/deformation and low-speed impact features. The airplane was destroyed by impact forces. Postaccident examination of the airplane’s fuel system revealed that both wing fuel lines were attached and secured to their respective fuel tanks and to the fuel selector assembly. The fuel lines were unbroken and did not exhibit fuel leakage. There was no usable fuel in either the left- or right-wing fuel tanks. Air was heard flowing from the wing’s respective fuel filler ports and into their respective fuel tanks when air was blown into the left- and right-wing fuel tank underwing vent tubes. Fuel system diagrams show that the airplane’s main fuel tank lines connect to the fuel selector assembly, which provide left, right, and off positions. Fuel cannot flow from a fuel tank when the selector is selected to the opposite tank. The fuel selector handle was found positioned to the right fuel tank. The fuel selector handle was rotated by hand and no detents were felt. The fuel selector handle was positioned to the right and then the left fuel tank, and air was blown into the fuel selector output line. The resultant airflow could be heard from each wing’s respective filler port. Air could not be blown through the fuel selector when the fuel selector handle was in the off position. The fuel flow transducer, which was part of the cockpit fuel flow indicator, was tested and met the manufacturer’s test specifications. Removal of left- and right-wing fuel tank fuel senders revealed that the metal float arm of the left fuel tank sender had an acute angular bend near its midpoint and near its float. The right fuel tank sender float arm had an approximate 45o angular bend near its midpoint. The shapes of both fuel sender arms were not in accor