ERA23FA249

A total loss of engine power for reasons that could not be determined.

The pilot departed on the third skydiving flight of the day with four skydivers on board and climbed to about 11,000 ft mean sea level (msl) when the jumpers departed the airplane. The pilot flew back to the airport and reported over the common traffic advisory frequency (CTAF) that he was descending through 6,000 ft msl. The operator reported hearing the pilot make another radio call on the CTAF but the “…call did not sound like a normal one and I could not identify what he said. I thought by the sound of his voice something was off.” A witness heard the engine sputtering followed by the engine losing power and then heard the impact. The airplane impacted trees and terrain about 1 nautical mile from the center of the intended airport, coming to rest in a nose-low, tail-high attitude with the left wing separated at the wing root. Postaccident examination of the flight controls revealed flight control continuity, and all fractures were consistent with overload. The examination of the engine revealed crankshaft, camshaft, and valvetrain continuity. The air induction, exhaust, lubrication systems, magnetos, and spark plugs revealed no evidence of preimpact failure or malfunction. The carburetor heat was found in the off position. Postaccident examination of the airframe revealed that the right-wing fuel bladder was intact and contained about 25 ounces of fuel. The left-wing fuel bladder was breached; there was no evidence of significant fuel leakage from the ruptured left-fuel tank evidenced by minimal fuel blight of the vegetation in the immediate area. There was no evidence of fuel siphoning aft of either wing-tank fuel filler cap. The fuel selector was found in the left-tank detent. No fuel was found in the left- or right-inlet fuel lines or the outlet line of the fuel selector valve. No fuel stains were noted on the interior panel below the fuel selector valve. About 5 ounces of fuel were drained from the airframe fuel strainer and about 4 ounces were found in the carburetor bowl. The pilot fueled the airplane the day before by adding 30.3 gallons of 100 low lead fuel. The amount of fuel in the airplane before he added the fuel is unknown. He then flew two uneventful skydiving flights that day. The operator reported that on the next day the pilot flew another skydiving flight in the morning, and when the pilot returned from the flight, he checked the fuel level with a dipstick and stated that he had 40 gallons of fuel on board. The operator reported that the pilot had enough time to refuel the airplane but chose not to. The pilot flew another skydiving flight before the accident flight, which was the fifth flight since he fueled the airplane the day before. The operator reported the airplane burned 7 to 9 gallons of fuel per skydiving flight. The pilot used a fuel dipstick to assist in determining the fuel level in the tanks. However, the fuel dipstick used was not made for the make and model of the accident airplane. Therefore, a fuel conversion chart was created to indicate how much fuel was actually in the tank when the dipstick was used. If the airplane had 40 gallons of fuel on board as the pilot stated, there should have been enough fuel for the intended flight. However, had the pilot misinterpreted the fuel dipstick reading, he may have believed he had about 43 gallons of fuel on board, as indicated by the dipstick, when instead there were about 24 gallons, as indicated by the conversion chart. In that case, during the next three flights, the airplane could have sustained fuel exhaustion as a result of the fuel burn and the unusable fuel in each tank. The nearest weather station, located about 29 miles from the accident site, indicated the temperature and dew point spread was 27°C and 8°C, respectively, which was conducive for carburetor icing at glide or cruise power. About 1443, ADS-B data indicated that the airplane began its descent from about 11,000 ft msl and 3 minutes later it descended through 6,000 ft msl, about a 1,666 ft-per-minute rate of descent. The last ADS-B radar point was about 1450, and the airplane was about 1,500 ft msl. While the pilot had a history of diabetes being treated with a medication and a documented history of retinopathy, it is unlikely that the pilot had symptoms of severe high or low blood glucose at the time of the accident. Minor symptoms of diabetes, such as fatigue or blurry vision, could not be entirely excluded. Due to his heart disease, the pilot was at significantly increased risk of a sudden impairing or incapacitating cardiac event, including angina, arrhythmia, or heart attack. There is no autopsy evidence that such an event occurred; however, such an event does not leave reliable autopsy evidence if it occurs immediately before death. It is possible that the pilot’s report of the fuel level using the dipstick did not account for the fuel conversion chart that would have indicated that the airplane had about 24 gallons of fuel on board, and not the reported 40 gallons. In this scenario, the pilot would have departed on the flight with substantially less fuel than anticipated, and the engine lost power due to fuel exhaustion. However, the evidence supports another possible scenario: the airplane was descending from about 11,000 ft msl and at a high rate of descent in atmospheric conditions that were conducive to carburetor icing in cruise and glide power. The carburetor heat was found in the off position after the accident. Had the pilot not used carburetor heat during the descent, it is also possible that the engine sustained a complete loss of engine power due to carburetor icing. Accordingly, the definitive cause of the total loss of engine power could not be determined.

The weather recorded at the Greater Binghamton Airport (BGM), Johnson City, New York, located about 29 miles from the accident site, indicated the temperature and dew point spread was 27°C and 8°C, respectively. According to FAA Special Airworthiness Information Bulletin CE-09-35, Carburetor Icing Prevention, these conditions were conducive for carburetor icing at glide or cruise power. About 1443, the ADS-B data indicated that the airplane began its descent from about 11,000 ft msl and 3 minutes later it descended through 6,000 ft msl, about a 1,666 ft per minute rate of descent. The last ADS-B radar point was about 1450, and the airplane was about 1,500 ft msl. The pilot was a part-time contract pilot for Just Jump SkyDiving, LLC. According to a co-owner of the airplane/operator, he began flying with them in the Spring of 2022, and flew until the end of October, with some intermittent flying in the winter, weather permitting. They began their 2023 flying “season” in April. According to the “Flight Competency and Proficiency Checks” paperwork provided by Just Jump SkyDiving, LLC, the pilot’s last recurrent check was performed in the accident airplane on October 8, 2022. The flight time was reported to be 1.3 hours, and the results were marked “Approved.” All items on the form were marked “S” or satisfactory. He was also qualified in their other Cessna 182E. Inspection of his personal effects located at the operator’s facility revealed a fuel dipstick that was identical to the dipstick located in the accident airplane. There was no conversion chart located in his personal effects, or in the wreckage, to correlate the readings on the stick with actual fuel load in each tank. The operator later provided a copy of the conversion paperwork for the dipstick. The airplane was equipped with a cellular phone, an iPad for use with the Foreflight application, and an Electronics International engine monitor. The engine monitor did not store non-volatile memory, and the cellular phone did not have any accident-related data. The iPad was accessed, and a ForeFlight application was in the recently used app bin, but potential data was not recovered from the application due to account and user permission restrictions. According to the airplane Owner’s Manual, the total volume of each wing fuel tank was 32.5 gallons, while the usable amount of fuel in each fuel tank for all flight conditions was 27.5 gallons, resulting in a total usable amount of fuel in all flight conditions of 55.0 gallons. The manual also indicated that in level flight an additional 3.5 gallons of fuel is available, resulting in an unusable fuel load in level flight of 1.5 gallons. One co-owner of the airplane, who had owned it for about 9 months, reported that the typical fuel burn for a skydiving flight was 7 to 9 gallons. Fuel records indicated that the pilot added 30.3 gallons of 100 low lead fuel to the airplane on May 27, 2023, likely after the first flight of the day. The fuel level in the airplane before he added the fuel is unknown. Two more skydiving flights were flown that day. A co-owner of the airplane/operator reported the pilot performed a preflight inspection of the airplane about 1000 hours on May 28, 2023, and then flew a skydiving flight lasting about .7 hours, based on the tachometer time. After landing, the pilot used a dipstick and informed one co-owner that the airplane had 40 gallons of fuel. Including the accident flight, the airplane was subsequently flown on two additional skydiving flights, about 12,000 ft msl. The accident flight was the fifth flight since the airplane was refueled. Located at the accident site was a “Navigation Log” page and a small log each containing handwritten entries. The Navigation Log contained entries including the registration of the accident airplane, winds aloft, date (May 28, 2023), number of flights, “3041.57,” and “fuel,” and two columns immediately beneath it specifying “R23” and “L20.” The small log contained entries including date, numbers consistent with tachometer time out and in, and for one entry of the accident date the accident pilot’s first name. Correlation of the Navigation Log and the small log revealed the entry on the Navigation Log of “3041.57” was consistent with the tachometer start time for the 1st flight of May 28, 2023. The pilot used a fuel dipstick to assist in determining the fuel level in the tanks. However, the fuel dipstick used was not made for the make and model of the accident airplane. Therefore, a fuel conversion chart was created to indicate how much fuel was actually in the tank when the dipstick was used. A review of the dipstick conversion chart provided by the operator revealed the actual fuel level did not go higher than “19” gallons, and there was no dipstick reading of 23. Correlating the values of 20 and 23 as annotated on the Navigation Log to the conversion chart, either by exact entry or interpolation, resulted in actual fuel levels of 11 gallons and 13.5 gallons, respectively, for a total of 24.5 gallons. A postmortem examination of the pilot was performed at the Lourdes Hospital Department of Pathology, Binghamton, New York. The cause of death was reported to be multiple blunt force injuries, and the manner of death was accident. Forensic toxicology was performed on specimens of the pilot by the FAA Forensic Sciences Laboratory, Oklahoma City, Oklahoma. The toxicology report indicated glucose was detected in the vitreous and urine at 13 mg/dL and 14 mg/dL, respectively, and an unquantified amount of metformin was detected in the submitted blood and urine specimens. According to the NTSB Medical Officer’s Factual Report, the pilot had a history of diabetes and moderate non-proliferative diabetic retinopathy treated with laser therapy. He reported taking metformin, a prescription medication commonly used to treat diabetes. His last aviation medical examination was April 4, 2023; at that time, he was issued a second-class medical certificate by Special Issuance, with the limitation that the certificate was not valid for any class after April 30, 2024. The pilot’s most recent Authorization for Aviation-Medical-Examiner Assisted Special Issuance for diabetes and diabetic retinopathy was granted May 1, 2023. The pilot’s last hemoglobin A1c in March 2023 was 7.6%. (HbA1c is an indirect measure of a person’s average blood sugar over approximately the preceding 3 months. For a person with diabetes, an HbA1c of less than 7% generally indicates good diabetes control.) The FAA Forensic Sciences Laboratory considered glucose levels above 125 mg/dL in vitreous fluid or above 100 mg/dL in urine to be abnormal. The NTSB Medical Factual report also indicated the autopsy report documented severe coronary artery atherosclerosis, including 90% narrowing of the left anterior descending artery, and mild atherosclerosis of the aorta and cerebral arteries. Cardiac hypertrophy and a mild increase in perivascular and interstitial fibrosis in the left ventricular wall on microscopy was also reported. Metformin is a prescription medication commonly used to help control blood sugar in diabetes and prediabetes and is not typically impairing. The airplane crashed in a wooded area located about 1 nautical mile west-northwest of the center of OIC. The wreckage came to rest on a magnetic heading of about 189° on a slight down sloping terrain and was in a 49° nose-low and tail-high attitude. It was also in a right-wing-high attitude; the left wing was separated at the wing root, which remained in close proximity to the main wreckage. Further examination of the accident site revealed a very slight smell of fuel in the area of the separated left wing. Very slight fuel blight of tree leaves adjacent to the resting position of the left-wing root was noted. A broken tree limb near the resting position of the left wing was noted about 30 ft abov