Crescent City-Del Norte County Regional (Jack McNamara)

About 13 minutes after takeoff for a medical transport flight, while climbing through about 14,900 ft mean sea level (msl), the pilot reported to air traffic control (ATC) that he was smelling smoke in the cockpit and would be returning to the originating airport. The flight was cleared to return with a descent at pilot's discretion to 9,000 ft msl. The pilot replied, "okay," and said that it looked like he was going to lose some power shortly. The pilot then stated that he had smoke in the cockpit, declared an emergency, and requested that ATC contact the fire department. About 1 minute 15 seconds after the initial report of smelling smoke, the pilot made the last radio transmission of the flight stating that he had three people on board. The wreckage was located about 9 hours later in an area of brush and heavily forested terrain. Portions of the burned and fragmented wreckage were scattered along a debris path that measured about 2,400 ft in length, which is consistent with an inflight breakup. The center fuselage and cockpit areas were largely intact and displayed no evidence of fire; however, there was an area of thermal damage to the forward fuselage consistent with an inflight fire. The thermal damage was primarily limited to the floor area between the two forward seats near the main bus tie circuit breaker panel and extended to the forward edge of the wing spar. All exposed surfaces were heavily sooted. Some localized melting and thermal-related tearing of the aluminum structure was present. The primer paint on the floor panels under the right aft corner of the pilot seat and the left aft corner of the co-pilot seat was discolored dark brown. An aluminum stringer in this location exhibited broomstrawing indicating that the stringer material was heated to near its melting point prior to impact. A single wire located in the area exhibited notching consistent with mechanical rubbing. The main bus tie circuit breakers were partially missing. The remaining breakers were heavily sooted on their aft ends, and one breaker was thermally discolored. Areas of charring were on the backside of the panel. Examination of the wiring in this area showed evidence of electrical arcing damage. Four hydraulic lines servicing the landing gear system were located in this area, and all the lines exhibited signs of thermal exposure with melting and missing sections of material. Six exemplar airplanes of the same make and model as the accident airplane were examined, and instances of unsafe conditions in which electrical lines and hydraulic lines in the area of the main bus tie circuit breaker panel were in direct contact were found on all six airplanes. Some of the wires in the exemplar airplanes showed chafing between hydraulic lines and the electrical wires, which, if left uncorrected, could have led to electrical arcing and subsequent fire. Based on the unsafe conditions found during examination of the exemplar airplanes and the thermal damage to the area near the main bus tie circuit breaker panel on the accident airplane, including broomstrawing of the aluminum structure, electrical arcing damage to the wiring, and melting of the hydraulic lines, it is likely that an electrical wire near the tie bus circuit breakers chafed on a hydraulic line and/or airplane structure, which resulted in arcing and a subsequent in-flight fire that was fed by the hydraulic fluid.

The pilot and the pilot-rated passenger were flying from their home, which was located at a residential airpark where no fuel services were available, to an airport located about 37 miles away. According to the passenger, shortly after departure, she queried the pilot about the airplane's apparent low fuel state. The pilot responded that one of the fuel gauges always indicated more available fuel than the other, and that if necessary they could use fuel from that tank. However, about 15 minutes after departure, the pilot advised air traffic control that the airplane was critically low on fuel. About 5 minutes later, both engines lost total power, and the airplane descended into trees and terrain. Examination of the airframe and engines after the accident confirmed that all of the airplane's fuel tanks were essentially empty, and that the trace amounts of fuel recovered were absent of contamination. Based on the autopsy and toxicology results, the pilot had emphysema, hypertension, dilated cardiomyopathy, and severe coronary artery disease; however, given that the passenger did not report any signs of acute incapacitation, and that the pilot did not communicate any medical issues to air traffic control, it does not appear that these conditions affected his performance on the day of the accident. The pilot did not report any chronically painful conditions to the FAA in his most recent medical certificate applications; however, postaccident toxicology tests indicated that the pilot was taking several pain medications (diclofenac, gabapentin, and oxycodone) and one illegal substance (marijuana). Based on the medications' Food and Drug Administration warnings, gabapentin and oxycodone may be individually impairing and sedating; their combined effect may be additive. The effects of the underlying conditions that necessitated the medication could not be determined. It is impossible to determine from the available information what direct effect the marijuana alone may have had on the pilot's judgment and psychomotor functioning; however, the combination of marijuana, oxycodone, and gabapentin likely significantly impaired the pilot's judgment and contributed to his failure to ensure the airplane had sufficient fuel to complete the planned flight.

The crew (one instructor and one student pilot) was engaged in a training flight from Crescent City to Eureka. Following a night takeoff from Crescent City-Jack McNamara Airport, the twin engine airplane adopted a low rate of climb when it crashed in flames on the Castle Rock Island (238 feet ASL) located about a mile south of the departure end of runway. The aircraft was destroyed and both occupants were killed.