History of Flight
On December 10, 2023, at 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. The ground controller issued a taxi clearance to runway 35R, and the pilot declined VFR flight following. At 1015:37, the pilot contacted the tower controller and stated he was holding short of runway 35R and ready to depart. The tower controller cleared the pilot for takeoff.
ADS-B track data revealed liftoff before midfield and the airplane climbing through 350 ft above ground level as it flew over the end of runway 35R. A security camera captured the airplane in a climb, with possible intermittent smoke trailing behind. After takeoff, the airplane continued climbing north. At 1018:21, it entered a left turn, and about 3 seconds later the pilot told the tower controller, "… we’re a return for landing." The controller cleared the pilot to enter a left downwind for runway 35R. At 1018:38, the pilot transmitted, "okay, we are losing power [unintelligible] tower I’m gonna land on [unintelligible]." During the transmission, the engine was heard running roughly.
At 1018:43, the airplane was about halfway through a 180° turn toward the airport when it began descending from the flight’s maximum altitude of about 2,165 ft mean sea level (msl). At that time, the airplane was about 1.7 nautical mile from the runway 17R threshold and 882 ft above the runway threshold height. At 1018:51, the pilot declared an emergency. The tower controller cleared the pilot to land on the runway of his choice. The surface wind was reported as from 320° at 5 knots.
ADS-B data showed the airplane continued descending toward the airport. The final ADS-B return was recorded at 1019:50 about 0.4 nm north of the runway 17R threshold at an altitude of about 1,445 ft msl, 162 ft agl, 68 knots calibrated airspeed, and descending about 1,355 feet per minute. Security camera footage showed the airplane descending with light colored smoke trailing. At 1020:04, dark smoke began rising from the accident site.
Two witnesses reported smoke trailing from the airplane and that the engine was running roughly before the accident. One witness noted the trailing smoke was a gray/white color. A third witness stated the engine was sputtering as the airplane flew over, then it made a 180° turn toward the airport.
Personnel and Aircraft Information
The pilot’s flight logbook was not located. FAA documentation indicated that on October 7, 2023, the pilot passed his private pilot check ride, reporting a total flight time of 80.2 hours, of which 10 hours were as pilot-in-command. ADS-B data indicated the airplane was flown at least 17.5 hours after purchase on June 30, 2023; about 9.5 hours were flown after the pilot received his certificate.
The airplane was a Beech A23-24, equipped with a Lycoming IO-360-A2B engine. According to maintenance documentation, the last major overhaul of the engine was completed on June 6, 2005, at 398.92 hours (tachometer time). At the time of overhaul, the engine had 924.9 hours since new. On December 24, 2008, at 637.78 hours, all four cylinders were removed and overhauled due to low compression and excessive oil consumption. Postaccident calculations indicated the engine had 238.86 hours since major overhaul (SMOH) when the cylinders were overhauled.
On January 12, 2021, the recording tachometer was rebuilt and reset to 0.0 hours. Postaccident calculations indicated airframe total time (AFTT) and engine SMOH of 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 filter were replaced, and No. 1 cylinder was serviced due to low compression. The airplane was returned to service after an engine ground run and test flight. The last annual inspection was also completed on April 15, 2023. Postaccident calculations indicated AFTT of 1,607.21 hours and engine SMOH of 683.78 hours.
According to FAA registration records, the pilot purchased the airplane on June 30, 2023. A prepurchase inspection report dated June 22, 2023, indicated AFTT of 1,585.31 hours and engine SMOH of 684.5 hours. On November 3, 2023, at 225.0 hours (699.48 hours SMOH), the engine oil and filter were replaced, and an oil sample was submitted for analysis. The airplane was returned to service after an engine test run.
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 suggested internal corrosion could be an issue, recommending a borescope inspection, compression test, monitor oil temperature, and check the oil filter. The report also stated that excessive oil consumption could be an indication of engine issues.
On December 5, 2023, the aviation mechanic who submitted the oil sample emailed the pilot/owner about the results, noting high chrome levels possibly from internal corrosion and cylinder wear. The mechanic recommended recurring 25-hour oil sample analyses and 50-hour compression checks with borescope inspections. The pilot/owner agreed to advise 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. Postaccident calculations indicated AFTT of 1,631.81 hours and engine SMOH of 708.38 hours. The mechanics stated that none of the engine oil system components were loosened or removed during installation.
The airplane’s recording tachometer was destroyed by the postimpact fire, preventing calculation of times at the accident.
Wreckage and Impact Information
The airplane impacted a 15-foot-tall pile of concrete rubble at a concrete recycling facility on an approximate 180° heading. The upper portion of nose landing gear, nose gear fork, nose wheel and tire, and right main landing gear were found separated among the top of the rubble. Tire markings and red paint transfer (matching aircraft color) were observed on multiple pieces of concrete. One tire track was outlined by an oily substance consistent with engine oil. The fractured nose gear segment and nose wheel tire were coated with a thin layer of oil. The right lower cowling, also coated with oil, came to rest next to the nose gear segment. The outboard 6 ft of the right wing fractured and came to rest inverted at the bottom of the rubble pile with significant thermal damage.
The main wreckage came to rest in an open grass area on a south-southwest heading about 40 ft beyond the concrete rubble pile. The accident site elevation was 1,286 ft msl. The main wreckage consisted of the fuselage, engine, propeller, left wing, inboard portion of the right wing, and tail section. The left main landing gear separated and was found about 60 ft past the main wreckage. All structural components and flight control surfaces were located at the site.
Extensive postimpact fire thermally damaged most of the airplane, including fuselage skin and structure. The inboard portion of the right wing separated at the wing root. Thermally damaged portions of the horizontal stabilator and tail beacon were identified. The right wing’s integral fuel tank upper surface was consumed by fire; the left wing’s upper skins forward of the main spar were mostly consumed.
Examination of the flight control system was limited due to thermal damage, but no evidence of a flight control cable separation was found. The flap selector was in the retracted position. The airframe examination revealed no evidence of a preimpact mechanical malfunction or failure that would have precluded normal operation.
The airplane was normally parked in a hangar at PWA. Examination of the hangar revealed 11 empty 1-quart bottles of engine oil and evidence of non-recent minor oil puddling on the floor. There was no oil leak evidence between the hangar door and the taxiway.
There was evidence of a significant oil leak and puddling on the unmarked asphalt taxiway, consistent with the airplane being stationary for an extended period with the engine running. Oil spray from propeller wash was evident. A dark black oily tire track extended from the puddle toward taxiway C1. A smaller oil puddle was near the transition to concrete taxiway C1. Oil drips and nose wheel tire tracks continued on taxiway C1 to the runup pad. There was evidence of a significant oil leak and puddling on the runup pad, also consistent with stationary running. Additional oil drips and nose wheel tracks were evident to the hold short lines for runway 35R, and evidence of an oil leak where the airplane stopped before the hold short lines.
Engine Examination
The engine remained attached to the mounts, which remained attached to the firewall. The engine sustained thermal damage from the postimpact fire. The exhaust was crushed upward and aft. The rear of the oil sump and lower accessory case were consumed by fire. There was an opening punched out of the top of the engine case inboard of the No. 2 cylinder base, and multiple holes punched out of the lower side of the engine case inside the oil sump between cylinders 1 and 2. Connecting rods 1, 2, and 3 were broken and deformed. Numerous pieces of connecting rod, rod caps, and rod bolts were found in the remaining oil sump. There was a crack of the forward lower left crankcase between the base of cylinder 2 and the case split. Visual examination inside the crankcase and cylinder rocker boxes revealed an overall lack of oil wetting of internal drivetrain components, consistent with prolonged exposure to the postimpact fire.
The remote-mounted oil filter assembly was thermally deformed. The oil filter was safety tied. Oil hoses were thermally damaged and separated. Aluminum fittings were melted. The oil cooler was mostly consumed by fire; only the center core remained. Both supply and return hose ends at the cooler contained resolidified aluminum. All oil and fuel hoses were thermally compromised.
A borescope inspection of the cylinders revealed no anomalies. The No. 2 exhaust push rod shroud tube was dislodged; numerous shroud tubes were thermally deformed. All oil drain-back tubes exhibited significant thermal damage.
The propeller governor drive adapter was dislodged. The governor was mostly consumed by fire. The propeller governor oil line separated at both ends.
Both magnetos were thermally deformed. All ignition leads were thermally damaged. The top spark plug electrodes appeared worn with a dark sooty appearance.
The fuel servo was fractured separated from its flange, partially thermally deformed. The throttle and mixture cables remained attached. The flow divider was partially deformed, with the diaphragm consumed by fire. The engine-driven fuel pump was thermally damaged.
The propeller remained attached to the crankshaft. The pitch change mechanism and spring were separated. The outboard third of Blade A melted along the trailing edge; the blade was bent aft about 10° midspan. Blade B was bent forward 10° midspan. Neither blade exhibited leading edge scoring or gouging.
Additional Information
The pilot was taken to a hospital where resuscitative efforts were unsuccessful; he was declared dead at 1911 on the day of the accident. The Oklahoma Office of the Chief Medical Examiner performed the autopsy, determining the cause of death as thermal injuries and the manner as accident.
Toxicological testing of a hospital blood draw obtained at 1056 detected no ethanol, opiates, fentanyl, or benzodiazepines. Postmortem toxicological testing by the FAA Forensic Sciences Laboratory detected morphine, fentanyl, midazolam, lidocaine, etomidate, and propofol in femoral blood and urine; norfentanyl in urine (inconclusive in blood); and naproxen in blood but not urine. All detected substances are commonly administered during medical care following major injury.