North Wing Apache Sport — Polson, MT

What happened

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.

An editorial "what led to it / how to avoid it" analysis for this accident is generated separately and will appear here.