WPR14LA233

The pilot’s loss of airplane control during initial climb due to his experiencing an incapacitating medical event.

The private pilot had just installed the wing on the experimental light sport, weight-shift-control trike, and the accident flight was the first test flight since the wing's installation. The owner of the trike reported that he observed the trike's takeoff, climbout, and initial turns and that they appeared normal; however, after the trike crossed midfield, it entered an aggressive turn, which progressed into a corkscrewing descent into terrain. The pilot did not deploy the ballistic recovery parachute during the descent, and he sustained fatal injuries. The newly installed wing was not serialized, so its specific type could not be determined. According to a trike manufacturer representative, the wing was manufactured under previous ownership and was likely designed for a smaller trike; however, the combined weight of the trike, pilot, and fuel were within the trike's allowable gross weight limit, and the wing appeared to be attached at the correct keel hang point position. Postaccident examination of the airframe and engine did not reveal any anomalies that would have precluded normal operation. Witnesses reported that the engine was operating throughout the flight and descent, and propeller damage signatures indicated that the engine was operating at the time of impact. The pilot was operating under the provisions of sport pilot regulations; therefore, he was not required to hold a current Federal Aviation Administration (FAA) medical certificate as long as his most recent medical certificate had not been suspended or revoked. His most recent FAA medical certificate was issued about 5 years before the accident. At that time, he received a special issuance certificate valid for 2 years due to a history of high blood pressure and coronary artery disease, which had been treated with a stent. The autopsy of the pilot revealed evidence of coronary artery disease, including evidence of a previous heart attack. Therefore, the pilot's coronary artery disease increased his risk of experiencing another acute coronary event, including a heart attack and/or arrhythmia, that could have been incapacitating but left no clear evidence to be found during the autopsy. Further, toxicology testing detected two opioid pain medications, hydrocodone and tramadol, both of which are potentially impairing, in the pilot's blood. The drug's detected levels were well above typical therapeutic levels; the hydrocodone level was more than 3 times the upper therapeutic limit, and the tramadol level was 28 times the upper therapeutic limit, indicating that the pilot was chronically taking high doses of these medications. Even higher levels of tramadol were measured in the pilot's gastric contents, indicating that he may have taken a large dose of the extended release capsules fairly soon before the flight. Tramadol, particularly at high doses and in combination with other opioids, is associated with an increased risk of seizure, and an acute seizure would have caused the pilot to become incapacitated. The trike's descending flight trajectory and the pilot's failure to deploy the ballistic recovery parachute or shut off the engine in preparation for such a deployment indicate that he likely experienced an incapacitating medical event. Based on the pilot's medical history and the toxicology findings, it is likely that the pilot became incapacitated by either a seizure due to his tramadol use or a cardiac event.

The primary airframe components and wing components sustained crush damage, with most members exhibiting buckling, bending, or fracturing failures consistent with ground impact. The trike mast remained fixed at a hang point position 54 inches from the keel nose plate, and did not display any indications of movement. This distance appeared appropriate when compared to the Mustang III 15 meter wing specifications, which called for 54 inches +/- 1.5 inches. The wing canvas material was intact, except for a 16-inch-long tear adjacent to the center crossbar junction. The leading edge tubes were intact, and the wing cross bar's had both split midspan. All wing ribs were intact within their pockets, and both the cross tubes and the kingpost were intact. The control bar was bent about 30 degrees midspan, and both of the control frame vertical struts had separated midspan. The keel tube had separated into three sections, about 2 ft forward and 3 ft aft of the mast. All cables were intact at their respective fittings, with the exception of the cable connecting the right side of lower control frame to the aft end of the keel. This cable separated at the swage on the control bar, and exhibited "cup and cone" failure signatures to each wire consistent with an overload (impact) failure. The wing was marked, "North Wing - APEX", and no serial or model number was found. According to a representative from North Wing, the wing was a model manufactured under previous ownership, and was designed for a smaller, single-place trike application with a gross weight limit of about 850 pounds. The representative stated that the mast position of 54 inches was appropriate. The engine remained attached to the airframe, and did not exhibit any indications of catastrophic failure. The three bladed composite propeller remained attached to its hub at the engine gearbox. One blade had fractured midspan, and remained partially attached. Both the remaining blades exhibited leading edge nicks. The fuel tank was ruptured, and according to the owner, contained about 12 gallons of fuel at takeoff. The pilot was in the front seat. The ballistic recovery parachute activation handle had become detached from the airframe, was in the undeployed position, and its lockout safety pin was not present. The activating cable sustained damaged to its outer sheeting, presumably during the impact sequence, and the rocket appeared to have been fired from the launch tube, partially extracting the parachute from the canister. The attachment bridles remained tied in place on the airframe structural members. The damage was consistent with a parachute deployment during the impact sequence when the activation cable and handle became detached from the airframe. A warning on the activation handle stated that the engine must be shut off before deploying the parachute. The 62-year-old male pilot was issued a private pilot certificate with ratings for airplane single-engine land in 1973, which he upgraded to a multiengine rating in 1983. He reported 975 total flight hours as of his last medical examination, on December 23, 2009. At that time he was 67 inches tall and weighed 191 lbs. A flight logbook for the pilot was not located; however, the trike's owner stated that the pilot had been flying weight-shift aircraft for many years. Review of the pilot's prior medical certificate applications revealed a history of high blood pressure, and in 2004 he had been diagnosed with coronary artery disease, which required the placement of a stent. In 2009, the pilot reported medications including aspirin, enalapril, hydrochlorothiazide, and atorvastatin, and subsequently his certificate was initially deferred. After a review of personal medical records he was issued a third-class special issuance medical certificate, limited by the need to have glasses available for near vision. It was marked, "Not valid for any class after 12/31/2011." FAA regulations do not require a current medical certificate to operate light sport aircraft, as long the most recent medical certificate has not been suspended or revoked. According to the FAA medical review, the pilot passed a stress thallium test in 2009 and an exercise stress test in 2010; since the pilot did not renew his medical certificate, there is no further clinical information regarding his coronary artery disease. Enalapril is a prescription medication used to treat high blood pressure. Hydrochlorothiazide is a mild diuretic used to treat high blood pressure and conditions that cause fluid retention, and atorvastatin is a cholesterol lowering agent. Autopsy An autopsy was performed by the Forensic Science Division, Department of Justice, State of Montana. According to the autopsy report, the cause of death was blunt force injuries and the manner of death was accident. In addition, the pathologist noted abnormalities of the heart. The posterior descending coronary artery was supplied by the right coronary artery and a stent was identified in the proximal right coronary artery. The remainder of the coronary arteries had areas of atherosclerosis producing no greater than 25-50% stenosis. A subendocardial 0.5 cm white fibrous scar was identified in the inferior wall of the left ventricle. The rest of the heart exam was unremarkable. Toxicology testing performed by the FAA's Civil Aerospace Medical Institute (CAMI) identified the following: > Atenolol and tamsulosin detected in muscle and liver. > Zolpidem detected in blood and liver. > Hydrocodone in liver (0.037 ug/g) and blood (0.164 ug/ml) along with its metabolite dihydrocodeine in liver but not in blood. > Tramadol in vitreous (2.918 ug/ml), brain (7.251 ug/g), blood (14.469 ug/ml), liver (26.948 ug/g), and gastric contents (336.45 ug/ml), along with its active metabolite O-desmethyltramadol in blood, gastric contents, and vitreous. Atenolol, a prescription medication often marketed with the name Tenormin, is a beta blocker used to treat high blood pressure and prevent recurrent heart attacks. Tamsulosin, a prescription medication often marketed with the name Flomax, is used to treat the symptoms of an enlarged prostate. Zolpidem is a sedative used to treat insomnia, commonly marketed with the name Ambien, and is a Schedule IV controlled substance. Hydrocodone, often marketed as Lortab and Vicodin, is an opioid analgesic used to treat severe pain and available by prescription as a Schedule II controlled substance. Typical therapeutic levels of hydrocodone are between 0.01 and 0.05 ug/ml. Tramadol, marketed with the names Ultram and Ultracet, is also an opioid analgesic available by prescription as a Schedule IV controlled substance. Typical therapeutic levels of tramadol are between 0.05 and 0.50 ug/ml. Both hydrocodone and tramadol carry a warning about impairment in mental and/or physical ability required for the performance of potentially hazardous tasks (e.g., driving, operating heavy machinery). In addition, tramadol carries an additional warning about the risk of seizures, "Seizures have been reported in patients receiving tramadol within the recommended dosage range. Spontaneous post-marketing reports indicate that seizure risk is increased with doses of tramadol above the recommended range. Concomitant use of tramadol increases the seizure risk in patients taking...Other opioids." Construction of the trike, serial number JENSEN761944, was completed in September 2005, and in January 2008, it was issued a special airworthiness certificate as an experimental operating light-sport weight-shift-control aircraft. The basis for issuance was for an existing aircraft without an airworthiness certificate that did not meet the criteria for Federal Aviation Regulations Part 103.1. At the time of the application, the owner reported a total airframe flight time of 72 hours. It had originally been equipped with a Rotax 503 UL DCDI, 50-horsepower, 2-cylinder, 2-stroke