HAWKER BEECHCRAFT CORP G58 — Credit, AR

What happened

The private pilot and passenger departed in the airplane for a business flight. After departure, the airplane flew southwest, climbed to about 2,300 ft above mean sea level, and started to descend. The flight continued to track southwest then it turned right to the northwest. The airplane’s flight track was lost about 10 minutes after takeoff at a location consistent with the accident site.

A pilot who took off behind the accident airplane reported that the runup and takeoff appeared normal. Several witnesses reported hearing and seeing the airplane prior to the accident. They described the airplane as flying low and the engines as not “sounding good” and that they were making “popping” noises.” One witness stated that it sounded like one engine was operating and the other engine was “sputtering”, before both engines quit.

A witness near the accident site reported that it sounded like one engine was operating and that the other engine alternately sounded as if it was making a “sputtering” sound and operating normally. Shortly after, it sounded like the engines quit. He said the airplane flew parallel to the high-tension powerlines at an altitude of an aerial application airplane. Another witness near the accident site, observed the airplane fly over his location about 1,000 ft agl, traveling east to west. He said the engines were “popping and sputtering” and making a “backfiring noise.”

Postaccident examination of the airframe revealed no anomalies. Blade A of the left propeller was separated from overstress while blade B and C were straight and unremarkable, and the leading edges were unremarkable. The left propeller was against the start lock and at approximately 18° of pitch at impact, consistent with a loss of engine power to the left engine.

An examination of the engines revealed all the fuel lines were thermally damaged. The left fuel servo screen was found to be about halfway obstructed and contaminated with an unknown black debris. Postaccident testing of the debris revealed similarities with materials used in aircraft fuel system components, particularly with hoses. It is likely the debris on the screen was soot from the postimpact fire and it could not be determined where and when the polymer signatures originated from.

Based on the available evidence, it is likely the left engine lost power while in flight. The witnesses reported hearing noises consistent with an engine misfiring and it likely was losing power; however, the reason for the loss of engine power could not be determined. Based on the flight track, it is likely the pilot attempted to perform a forced landing with one engine inoperative.

Given the variety of levels of ethanol and the absence of any in the pilot’s liver, it is most likely that the identified ethanol is from postmortem production rather than ingestion. The pilot’s previous use of cocaine (which often leads to withdrawal effects) and his simultaneous use of a large amount of butalbital and a small amount of temazepam were likely significantly impairing at the time of the accident and likely contributed to his inability to respond appropriately to the left engine’s loss of power.

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