CEN24FA057

A total loss of engine power due to multiple connecting rod failures from oil starvation associated with an extensive before takeoff oil system leak, the source of which could not be identified due to postaccident fire damage.

The pilot and his passenger were conducting a personal flight when, about 1.5 minutes after takeoff, the airplane entered a left turn back toward the airport. The pilot told the tower controller that he was returning to land because the engine was losing power and subsequently declared an emergency. During the pilot’s transmissions, the engine was heard in the background running roughly. The tower controller cleared the pilot to land on any runway and issued the current surface wind condition. Witnesses reported that the engine was running roughly and there was smoke trailing from the airplane. The airplane impacted a concrete rubble pile at a concrete recycling facility about 0.4 nautical mile (nm) from the runway threshold. An extensive postimpact fire thermally damaged most of the airplane. Postaccident examination of the pilot’s hangar revealed evidence of non-recent minor oil leaks often seen on hangar floors, and there was no evidence of an oil leak between the hangar and the asphalt taxiway. However, evidence of a significant oil leak and puddling was observed on the taxiway where the pilot likely started the airplane engine. The oil leak was consistent with the airplane being stationary for an extended period with the engine running. The nose landing gear subsequently deposited an easily discernible, dark black, oily tire track as the airplane began its taxi toward the runup pad and the runway. Additional evidence of a significant oil leak and puddling was observed on the runup pad where the pilot likely completed his before takeoff engine runup checks. Finally, evidence of an oil leak was observed where the airplane came to stop before the hold short lines for the departure runway. Based on the available evidence, the engine oil system likely began leaking shortly after the engine was started and continued during the taxi, before engine runup, takeoff, and climb portions of the flight. The pilot was likely unaware of the significant engine oil system leak before takeoff. Postaccident examination of the engine revealed evidence of multiple connecting rod separations due to a lack of oil lubrication. However, the extensive thermal damage to the engine and its oil system components precluded determination of the source of the oil leak. FAA toxicological testing of postmortem samples taken during the pilot’s autopsy detected multiple impairing substances. However, these impairing substances likely were administered during the pilot’s postaccident medical care and therefore did not cause any impairment at the time of the accident. Additionally, toxicological testing conducted on a hospital blood draw obtained from the pilot about 37 minutes after the accident did not detect any tested-for substances, which included ethanol, opiates, fentanyl, and benzodiazepines.

The pilot’s flight logbook was not located during the investigation. According to FAA documentation, just over two months before the accident, on October 7, 2023, the pilot passed his private pilot check ride that was administered by an FAA Designated Examiner. On his application for the pilot certificate, the pilot reported a total flight time of 80.2 hours, of which 10 hours were flown as pilot-in-command. Based on recorded ADS-B flight track data, the airplane was flown at least 17.5 hours after the pilot purchased the airplane on June 30, 2023. Of that total, about 9.5 hours were flown after the pilot received his private pilot certificate on October 7, 2023. According to available maintenance documentation, the last major overhaul of the Lycoming IO-360-A2B engine, s/n L-3904-51A, was completed on June 6, 2005, at 398.92 hours (all logbook entries were based on tachometer time). At the time of the overhaul, the engine had accumulated 924.9 hours since new. On December 24, 2008, at 637.78 hours, all four cylinders were removed and overhauled due to low cylinder compression and excessive oil consumption. Postaccident calculations based on previous tachometer readings indicated that the engine had 238.86 hours since major overhaul (SMOH) when the cylinders were overhauled. On January 12, 2021, the recording tachometer was rebuilt, reset to 0.0 hours, and then reinstalled in the airplane. Postaccident calculations based on previous tachometer readings indicated that the airframe total time (AFTT) and engine SMOH were 1,397.91 hours and 474.48 hours, respectively. On April 15, 2023, at 209.3 hours, 683.78 hours SMOH, the engine oil and oil filter were replaced, No. 1 cylinder was serviced due to low compression. The No. 1 cylinder bore was honed, and new gaskets and hold-down nuts were installed. The airplane was returned to service following an engine ground run and subsequent test flight that did not reveal any oil leaks or anomalies. The associated engine log entry indicated that the engine was inspected in accordance with an annual inspection and determined to be in an airworthy condition. Also completed on April 15, 2023, was the airplane’s last annual inspection. Postaccident calculations based on previous tachometer readings indicated that the AFTT and engine SMOH were 1,607.21 hours and 683.78 hours, respectively. According to FAA registration records, the pilot purchased the airplane on June 30, 2023. A prepurchase inspection report, dated June 22, 2023, at 210.1 hours, completed by an aviation mechanic from Twin Aviation Repair, LLC, Douglas, Georgia, indicated that the AFTT and engine SMOH were 1,585.31 hours and 684.5 hours, respectively. However, based on postaccident calculations based on previous tachometer readings indicated the AFTT was 1,608.01 hours. On November 3, 2023, at 225.0 hours, 699.48 hours SMOH, the engine oil and oil filter were replaced, and an oil sample was submitted to a laboratory for analysis. The airplane was returned to service following an engine test run that did not reveal any oil leaks or anomalies. The oil analysis report, dated December 5, 2023, indicated elevated levels of aluminum, chromium, and iron. The laboratory commented that there was “a lot of metal in this sample” and that internal corrosion could be an issue if the airplane had been sitting. The laboratory suggested a borescope inspection, compression test, monitor oil temperature, and check the oil filter for evidence of metal. Additionally, the laboratory report stated that excessive oil consumption could also be an indication of engine issues. On December 5, 2023, the aviation mechanic who submitted the oil sample sent the pilot/owner an email to discuss the results of the oil sample that was collected on November 3, 2023, during the last oil change. The mechanic wrote that the oil sample had high level of chrome and that it might be from internal corrosion and possibly attributable to cylinder wear. The mechanic also acknowledged that the cylinder compression values during the prepurchase inspection were nominal and that there had been recent cylinder work completed. As such, the mechanic recommended recurring 25-hours oil sample analyses, and 50-hour compression checks with borescope inspections until the chrome levels trended down to normal levels. The pilot/owner agreed and told the mechanic that he would advise him when the airplane had flown 25 hours since the last oil change. On December 1, 2023, at 233.9 hours, an E-Z Heat oil sump heater was installed on the engine. Postaccident calculations based on previous tachometer readings indicated that the AFTT and engine SMOH were 1,631.81 hours and 708.38 hours, respectively. The aviation mechanics who installed oil sump heater stated that the back screws of the lower cowling were removed to gain access underneath the engine to install the oil-sump heater, but none of the engine oil system components were loosened or removed to gain access to the engine sump. The airplane’s recording tachometer was destroyed by the postimpact fire, which prevented calculation of the airplane’s airframe and engine times at the time of the accident. The pilot was taken to a hospital where resuscitative efforts were unsuccessful, and he was subsequently declared dead at 1911 on the day of the accident. The Oklahoma Office of the Chief Medical Examiner performed the pilot’s autopsy. According to the pilot’s autopsy report, the cause of death was thermal injuries, and the manner of death was accident. The Oklahoma Office of the Chief Medical Examiner performed toxicological testing of a hospital blood draw that was obtained from the pilot at 1056 on the morning of the accident. This toxicological testing did not detect any tested-for substances, which included ethanol, opiates, fentanyl, and benzodiazepines. The pilot’s postmortem toxicological testing, conducted by the FAA Forensic Sciences Laboratory, detected morphine, fentanyl, midazolam, lidocaine, etomidate, and propofol in femoral blood and urine. Norfentanyl was detected in urine, but norfentanyl testing in femoral blood was inconclusive. Naproxen was detected in femoral blood but not in urine. The toxicological specimens tested by the FAA Forensic Sciences Laboratory were postmortem specimens, collected after the pilot’s postaccident medical care. All detected substances are commonly administered during medical care following major injury. On December 10, 2023, about 1019 central standard time, a Beech A23-24 airplane, N6945Q, was destroyed when it was involved in an accident near Oklahoma City, Oklahoma. The pilot and his passenger were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to recordings of air traffic control (ATC) communications at Wiley Post Airport (PWA), Oklahoma City, Oklahoma, at 1008:16, the pilot established contact with the ground controller and requested a visual flight rules (VFR) departure to the north. At 1008:42, the ground controller issued a taxi clearance to runway 35R via taxiway C1, cleared the airplane to cross runway 31, and asked the pilot if he wanted VFR flight following. At 1008:48, the pilot told the ground controller that he did not need VFR flight following and then correctly read back the taxi clearance. At 1015:37, the pilot contacted the tower controller and stated that he was holding short of runway 35R on taxiway A1 and was ready to depart to the north under VFR. At 1015:44, the tower controller cleared the pilot for takeoff on runway 35R. A review of ADS-B track data revealed that the airplane’s liftoff occurred before midfield and the airplane was climbing though 350 ft above ground level (agl) as it flew over the end of runway 35R. At 1016:57, a security camera located on a hangar near the east end of taxiway A5 captured the airplane in a climb from runway