ERA16FA288

The pilot(s) failure to maintain adequate airspeed during an attempted go-around, which resulted in an exceedance of the airplane's critical angle of attack and an aerodynamic stall.

The private pilot, who was seated in the left front seat, was making a cross-country flight in the twin-engine airplane with five passengers on board; the passenger seated in the right front seat was a commercial pilot. Shortly after departing, the pilot contacted air traffic control and requested visual flight rules flight following services to the destination airport. A variable quartering headwind prevailed about the time the airplane approached the destination airport's 2,999-ft-long runway, with an approximate headwind component of about 8 knots. Given the airplane's estimated landing weight and the prevailing weather conditions, the airplane's calculated landing distance was between 1,280 and 1,850 feet. Review of recorded data showed that the airplane crossed the runway threshold for landing at an altitude about 40 ft above the ground and at an estimated airspeed of 95 knots, about 9 knots faster than the airframe manufacturer's recommended final approach speed for its estimated weight. Witness interviews, surveillance video, and recorded data showed that the airplane touched down and bounced several times near the mid-point of the runway. The airplane then started to climb at an estimated airspeed of 68 knots, which was well below the balked landing climb speed of 90 knots, and near the published stall speed of 73 knots with the landing gear and flaps extended. The airplane made a shallow left turn and climbed to an altitude of about 100 ft above ground level. During the climbing turn, airplane's speed further decreased to an estimated 62 knots before it entered an aerodynamic stall and descended to impact terrain. Examination of the airframe and engines did not reveal any evidence of preimpact mechanical malfunctions that would have precluded normal operation. Postaccident weight and balance calculations indicated that the airplane was below its maximum gross landing weight and that the center of gravity was within limits. The pilot did not hold a valid Federal Aviation Administration medical certificate and had a history of significant medical issues, including hypertension, high cholesterol, diabetes, and heart disease; however, it is unlikely that the pilot's hypertension or high cholesterol contributed to the accident. Toxicology testing identified zolpidem, a prescription sleep aid, at below-therapeutic levels; because zolpidem undergoes postmortem redistribution and the tested blood came from the heart, the antemortem level was likely lower than the measured level. As a result, it is unlikely that the sedative effects from the zolpidem contributed to the accident. The pilot's diabetes could have contributed to the accident if he experienced acutely low blood sugar, which causes psychomotor slowing and eventually loss of consciousness, or had difficulty operating the airplane due to diabetic neuropathy. Further, an acute cardiac event in either the pilot or the pilot-rated passenger, who also had significant heart disease, could have contributed to the accident; however, the investigation was unable to determine whether any of the pilots' medical issues contributed the accident, and it is unlikely that both suffered an acute medical event at the time of the landing and subsequent loss of control during the go-around attempt. It could not be determined which of the two pilots was manipulating the controls and flying the airplane during the landing approach and subsequent go-around, as both the pilot (airplane owner) and the pilot-rated passenger were seated at a fully functional set of flight controls.

EZF was located about 2 miles south of Fredericksburg, Virginia. It was classified by the FAA as a public airport. The airport elevation was 85 ft msl. Runway 24 was oriented 235 degrees magnetic and was 2,999 feet long by 100 feet wide. It was an asphalt runway in good condition and was equipped with a visual approach slope indicator. At 1235, the reported weather at EZF was wind from 200° magnetic at 10 knots, wind direction variable from 190° to 250°, visibility 10 statute miles, sky clear, temperature 34°C, dew point 24°C, and altimeter setting of 29.96 inches of mercury. The Office of the Chief Medical Examiner, Richmond, Virginia, performed an autopsy of the pilot. The cause of death for the pilot was thermal injuries and blunt force trauma. According to the autopsy report, his heart was enlarged at 582 grams with wall thickening of the left ventricle, which measured 1.6 centimeters (cm). The septum was 1.2 cm thick, and the right ventricle was 0.3 cm thick. Atherosclerosis of the coronary arteries was described as "moderate to severe." In addition, the kidneys showed evidence of chronic hypertension. The FAA's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed forensic toxicology testing of specimens from the pilot. The pilot's toxicology testing found amlodipine, benazepril, salicylate, ibuprofen, triamterene, and zolpidem in urine and amlodipine and zolpidem (0.021 ug/ml) in blood. Of these drugs, only zolpidem, which is a prescription sleep aid, is considered impairing. (Amlodipine, benzepril, and triamterene are used to treat hypertension. In addition, testing identified 313 µg/ml of glucose in the urine but none in the vitreous. The pilot's hemoglobin A1C at the time of the accident was 10.6% indicating poor glucose control. He had begun reporting diabetes to the FAA in 2005 and had received special issuance medical certificates for several years after this. At his 2015 examination, he reported using several drugs for diabetes control and had a hemoglobin A1C of 10.1%. His medical certificate was revoked on June 18, 2015, for the use of disqualifying medications and failure to provide additional information. On his 2016 re-application, the pilot reported the use of amlodipine, benazepril, triamterene, and hydrochlorothiazide to treat hypertension, fenofibrate and colesevelam to treat high cholesterol, and canagliflozin and exenatide to treat diabetes. In addition, he reported using esomeprazole, liposome, vitamin D, and low dose aspirin. In June 2016, the FAA was informed that the pilot was no longer using canagliflozin, but other questions asked by the FAA remained unanswered by the time of the accident, thus, the pilot did not have a valid medical certificate at the time of the accident. The Office of the Chief Medical Examiner, Richmond, Virginia, performed an autopsy of the pilot-rated passenger. The cause of death for the pilot-rated passenger was thermal and inhalation injuries. According to the autopsy report, severe coronary artery disease was identified with 80% stenosis of the left anterior descending artery, right coronary artery, and left circumflex artery. There was no evidence of a previous heart attack. There was thickening of the ventricular wall without overall enlargement of the heart. The left ventricle was 1.5 cm thick, the interventricular septum was 1.4 cm thick, and the right ventricle was 0.4 cm thick. Forensic toxicology testing of specimens from the pilot-rated passenger performed by the FAA's Bioaeronautical Sciences Research Laboratory found diphenhydramine in urine and heart blood at levels too low to quantify. He had reported no chronic medical conditions or the use of any medications to the FAA. According to Federal Aviation Administration (FAA) records, the pilot, age 73, held a private pilot certificate with ratings for airplane single-engine and multi-engine land. The pilot did not possess a current medical certificate at the time of the accident. (For more information about the pilot's medical status, see the Medical and Pathological Information section of this report.) Review of the pilot's logbook revealed that he had accumulated 233.2 total hours of flight experience since April 30, 2001. His first recorded flight in the accident airplane was conducted on March 16, 2008, and he had logged a total of 189.1 hours in the airplane. According to the logbook, the pilot's flying was inconsistent with months of time between flights. In the previous 12 months and 90 days, he had logged 9.4 hours and 2.6 hours, respectively, all in the accident airplane. His most recent flight in the airplane was in June 2016. The pilot-rated passenger, age 64, held a commercial pilot certificate with ratings for airplane multi-engine land, single-engine land, single-engine sea, and instrument airplane. His most recent FAA second-class medical certificate was issued on May 11, 2016, with the limitation that he must have available glasses for near vision. A review of the pilot-rated passenger's logbook showed that he had accumulated 2,273 total hours of flight experience, of which 1,149.4 hours were in multi-engine airplanes. He had logged 5.9 hours in the accident airplane make and model (all in the accident airplane), and his last logged multi-engine flight was conducted in the accident airplane on October 22, 2015. Further review of his logbook showed that he had accumulated a total of 66.1 hours flight experience in multi-engine airplanes in the previous 10 years. The six-seat, twin-engine, low-wing, retractable-gear airplane was manufactured in 1969. It was equipped with 260-horsepower Continental IO-470-L engines and three-blade, controllable-pitch, Hartzell propellers. According to the airplane's maintenance records, the most recent annual inspection was completed on May 15, 2016, at an airframe total time of 4,224.4 hours. The airplane's maintenance records indicated that, on February 1, 2014, at 4,689.0 hours total time and 518 hours since major overhaul, the left engine was "disassembled, cleaned, inspected, repaired, and assembled." Also, at 2,301.4 hours total time and 620.8 hours since major overhaul, the right engine was "disassembled, repaired, and reassembled." On May 15, 2016, 61.9 hours after the February 1, 2014 engine work, both engines underwent their most-recent 100-hour inspection as part of the aircraft's annual inspection. Weight and balance calculations were performed based on the airplane's empty weight and balance as determined on October 11, 1999. The weights of the two pilots were acquired from medical records, while the weights of the four passengers were estimated based on medical autopsy results. The estimated weight at takeoff was 4,979 pounds, which was below the airplane's maximum gross weight of 5,100 pounds, while the estimated weight at landing was 4,679 pounds. The estimated centers of gravity for takeoff and landing were 84.5 inches and 84.6 inches, respectively, which were within the limits of 81.0 to 86.0 inches. The pilots operating handbook (POH) for the airplane in section IV, Normal Procedures lists the following airspeeds for safe operations; two-engine best angle of climb speed is 84 knots, the best rate of climb speed is 107 knots, the balked landing climb speed is 90 knots, and the stall speed with landing gear extended and flaps down is 73 knots. The stall speed with the flaps in the retracted position is 79 knots. A calculation of the airplane's expected landing distance assuming an approach at the prescribed airspeed of 86 knots at 50 feet above the ground, the weather conditions that prevailed at the time of the accident, and the airplane's estimated landing weight, indicate that the runway required to safely land and stop was 1,280 feet, with about 1,850 feet needed to clear a 50-foot obstacle. The accident site was located about 700 ft south-southeast of the departure end of runway 24 on an embankment a