ERA23FA370

The pilot’s failure to perform pre-takeoff engine runup and carburetor heat check procedures, which resulted in rotation with inadequate climb performance, and his subsequent failure to maintain adequate airspeed and exceedance of the airplane’s critical angle of attack, which resulted in an aerodynamic stall or mush shortly after takeoff. Contributing to the accident was the partial loss of engine power due to the formation of carburetor ice.

The pilot owned the airplane and was flying it on a local flight with a passenger interested in buying it. About 2 to 3 minutes elapsed between engine startup and the application of takeoff power, which included the time spent taxiing for departure. A witness reported hearing the engine misfiring while the airplane was taxiing but stated that the engine sounded normal during the subsequent takeoff roll. The airplane departed and, after becoming airborne, it entered what a witness described as a “very shallow” climb before it disappeared from the witness’s view. The passenger reported that the flight lasted about 3 to 5 minutes. He recalled feeling that the airplane “fell a little bit” and that the pilot said there was a wind gust and pulled back on the control yoke. The passenger recalled thinking that the airplane was too close to the tops of nearby trees. The next thing he recalled was waking up on the ground unable to move his legs; the passenger had not fastened the lap belt because he was unaware that the airplane was equipped with restraints. Postaccident examination of the engine and its systems, including operational testing of the magnetos and spark plugs, revealed no evidence of preimpact failure or malfunction. However, the tachometer needle was trapped about 1,600 rpm, suggesting reduced engine power at the time of impact. Although a witness reported that the engine sounded like it was misfiring when the airplane was taxiing for takeoff, there were no engine valvetrain issues were noted during the postaccident engine examination. Further, the passenger reported that he did not detect any change in engine sound between the application of takeoff power and the accident. Thus, it is unlikely that a stuck exhaust valve condition (which could result in misfiring) occurred after takeoff. Although the carburetor bowl contained minimal fuel, the carburetor was impact-separated from the engine, and it is possible that some fuel could have leaked from the carburetor before the wreckage was recovered and the carburetor examined. The primer was found unlocked and partially extended; however, it could not be determined whether that condition existed before departure. Had the primer been unlocked during the entire flight, it was likely that the engine would have been operating with an excessively rich fuel to air ratio that would have been detectable by sooty spark plugs; a condition that was not evident during the postaccident engine examination. The temperature and dew point at the time of the flight were conducive to the formation of “serious icing at glide [idle] power,” and evidence from the pilot’s cellular phone suggests that the pilot could have been aware of those conditions, having called the airport weather information number about 17 minutes before the accident. However, according to the passenger, the pilot did not perform an engine run-up or check or apply carburetor heat before takeoff. Thus, it is likely that, during taxiing operations, which are typically performed at low engine power settings, the carburetor accumulated ice. For an airplane equipped with a fixed-pitch propeller, carburetor ice formation results in reduced engine power. Examination of the airplane found the carburetor heat control partially extended, which is indicative that the pilot likely recognized the partial loss of engine power and applied carburetor heat in flight; however, it could not be determined at what point in the flight the application of carburetor heat may have occurred. Regardless, it can take from about 30 seconds to several minutes for carburetor heat to melt an ice accumulation and fully restore engine power. Based on the passenger’s report that the airplane felt like it “fell,” his observation that the pilot responded to the sink rate by pulling back on the control yoke, and the crush damage observed on the nose and wings of the airplane, it is likely that the pilot, while maneuvering the airplane over the residential area, failed to maintain the proper airspeed, which resulted in the exceedance of the airplane’s critical angle of attack and the airplane entering an aerodynamic stall or mush condition. Further, although the fuel load at the start of the flight could not be determined, based on the reported weights of the pilot and passenger, any usable fuel amount greater than about 1.9 gallons would result in the airplane being over maximum gross weight. At the time of the accident, the pilot did not possess current FAA medical certification or BasicMed qualifications. The pilot had medical conditions including seizure disorder and severe heart disease that placed him at increased risk for an impairing or incapacitating medical event. Although such an event may not leave reliable autopsy evidence if it occurs just before death, there was no autopsy evidence that such an event occurred, and the surviving passenger’s account did not indicate pilot incapacitation. The pilot’s hemoglobin A1c (HbA1c) indicated marginal long-term control of his diabetes. Based on his high urine glucose, his blood sugar may have been elevated at the time of the accident. Based on his vitreous glucose and his witnessed behavior, it is unlikely that he was experiencing major metabolic disturbance related to high blood sugar at the time of the crash. It also is unlikely that he was experiencing severe low blood sugar at the time of the accident. Diabetes symptoms such as fatigue and blurry vision cannot be excluded based on available medical evidence. The pilot’s medical conditions (including cardiovascular disease and possibly the condition being treated with citalopram) and use of medication (including levetiracetam) also were associated with increased risk of impaired cognitive and psychomotor performance. However, the extent to which the pilot’s medical conditions and their related treatment may have been significant is not clear from the available medical evidence and accident circumstances. Overall, the pilot was at increased medical risk of impairment, but there is no specific evidence that a medical factor contributed to the accident.

The pilot’s last aviation medical examination was January 27, 2012. He reported a history of diabetes and high blood pressure and using the prescription oral diabetes medication metformin, the prescription blood pressure medications lisinopril and nifedipine, and the prescription cholesterol-controlling medication pravastatin. The Aviation Medical Examiner (AME) documented a HbA1c of 7%. The pilot was issued a second-class medical certificate by AME-Assisted Special Issuance (AASI); he had been granted an Authorization for Special Issuance in September 2011 for high blood pressure and diabetes requiring oral medication. The most recent medical certificate was not valid for any class after January 31, 2013, and was limited by a requirement to wear corrective lenses and possess glasses for near/intermediate vision. The pilot’s most recent Authorization for Special Issuance was granted in March 2012, for high blood pressure and diabetes requiring oral medication. The pilot completed a BasicMed Course and reported completing a BasicMed Comprehensive Medical Examination Checklist (CMEC), both most recently in July 2019. The pilot’s daughter reported that the pilot had a history of seizures, for which he was taking the medication levetiracetam (sometimes marketed as Keppra). She stated that his last seizure had been in August or September 2023, within the 4-6 weeks before the accident. She stated that his seizures always occurred at dusk and were characterized by uncontrolled muscle spasms during which he was “present.” She stated that the pilot had undergone open-heart surgery in 2011 and had later had stents installed. Limited medical history information in available hospital records for the pilot included history of coronary artery disease, heart attack, coronary artery bypass grafts in 2012, two cardiac stents, high blood pressure, high cholesterol, and chronic obstructive pulmonary disease. Home medications documented in the hospital records included citalopram, losartan, amlodipine, metformin, montelukast, glimepiride, ezetimibe, and clopidogrel. Additional documented home medications included baby aspirin (available without a prescription and commonly used to lower cardiovascular risk), ranolazine (a prescription medication that may be used for chronic heart-related chest pain), atorvastatin (a prescription medication commonly used to help control cholesterol and reduce cardiovascular risk), dulaglutide (a prescription injectable medication that may be used as part of diabetes treatment), esomeprazole (available without a prescription for stomach acid suppression), guaifenesin (available without a prescription for relief of chest congestion), and docusate sodium (a stool-softener available without a prescription). No seizure history or seizure medication use was documented in hospital records. The two-place, low-wing airplane was equipped with a fixed-pitch, two-bladed, McCauley metal propeller. According to the airplane’s type certificate data sheet, the engine limit for all operations was 2,575 rpm. A review of the maintenance records revealed the airplane’s last annual inspection was performed on February 6, 2006. At the time of the accident, the airplane had accrued about 77 hours since the inspection was performed and 1,736 hours total time. The engine had accrued 1,736 hours since new, and 642 hours since last overhaul in 1977. A review of FAA aircraft registry records revealed that the airplane’s registration was not current and that the “N” number had expired. The airplane was weighed at the last annual inspection and the weight and balance form specified the maximum weight was 1,260 lbs, the empty weight was 845 lbs, the empty weight center of gravity (c.g.) was 25.54 inches aft of datum, and the useful load was 415 lbs. Based on this information, and considering that the pilot weighed 204 lbs (per the medical examiner) and the passenger weighed about 200 lbs (per information he provided in his interview), any usable fuel load greater than 11 lbs, or about 1.9 gallons, would exceed the airplane’s maximum gross weight. According to fueling records, the pilot purchased 10.89 gallons of 100 low lead fuel (100LL) at FZG about 1618 on September 11, 2023, two days before the accident. The pilot’s family reported that, in anticipation of performing taxi tests, 2.5 gallons of fuel were added into each wing fuel tank the day before the accident. The total fuel quantity in each tank at the time of the accident flight’s departure could not be determined. An airframe and powerplant mechanic at FZG reported that, the day before the accident, the pilot came into the hangar where the mechanic was working and used the spark plug cleaning and test machine. The mechanic said that the pilot cleaned the spark plugs but did not test them. The mechanic reported that the pilot did not tell him why he needed to clean the plugs. The passenger reported that the pilot informed him that the airplane had undergone a recent annual inspection performed by an individual. That individual, an airframe and powerplant mechanic with an inspection authorization, informed an FAA inspector postaccident that he had never performed any annual inspection or work on the airplane. According to members of the pilot’s family, the individual shared a hangar with the pilot, and the individual was present and interacted with the pilot while the pilot performed an inspection of the airplane during the 2 days before the accident. The pilot did not hold an airframe and/or powerplant mechanic certificate. A booklet labeled “Owner’s Manual” was part of the obtained records for the airplane. The booklet, which referenced the Ercoupe 415-C and other models, contained a “Before Starting Engine” checklist that included an item for fastening the seat belts and a “Starting Engine” checklist that included an item for using the engine primer, with a handwritten note next to it stating “close & lock.” It also contained a “Before Takeoff” checklist that specified engine run-up procedures that included checking the operation of the magnetos and the carburetor heat. According to a representative from the airplane’s type certificate data sheet (TCDS) holder, no flight manual or owner’s manual was available for the model 415-C. The representative stated that, when requested, the TCDS holder would provide an owner with a copy of the flight manual for the model 415-D. The FAA-approved “Airplane Flight Manual” for the model 415-D contained a takeoff performance chart that provided the takeoff distance to clear a 50-ft obstacle for an airplane equipped with a metal, fixed-pitch propeller; the chart assumed an airplane gross weight of 1,400 lbs, zero wind, and a paved runway. Based on the temperature and pressure altitude (used to calculate the pressure altitude) at FZG about the time of the accident flight’s departure, the calculated takeoff distance to clear a 50 ft obstacle was about 2,332 ft. The calculated distance to clear the 50 ft obstacle did not account for the slightly downsloping runway. The pilot’s and the passenger’s cellular phones were recovered from the accident site and retained for readout by the NTSB Vehicle Recorder Division for information relevant to the accident flight. The passenger provided a passcode for his cellular phone, but the passcode did not unlock the phone. As a result, no information could be reviewed, and the NTSB returned the phone to the passenger’s attorney. The pilot’s cellular phone was not passcode locked. No pertinent photos or other media were discovered on the device, and no electronic references were found that were related to maintenance of the airplane. Call records showed that, at 1408 on the day of the accident, an outgoing call was made to the FZG automated weather observing system (AWOS) for a duration of about 1 minute. At 1637, anothe