iscover
Faulty wiring brought down a Beechcraft B58 Baron in a fatal crash near Kununurra, WA, last year, the ATSB has found.
The fire, likely sparked by a fault in the landing gear electrical system that ignited fuel from the cabin heater supply line, filled the cabin with smoke that caused the pilot to lose control and collide with the ground. The pilot escaped with severe injuries, while the sole passenger was killed.
“The fuel line to the aircraft’s cabin heater passes through the area where the pilot reported the fire initiated, and multiple looms of electrical wiring pass through that area as well,” ATSB chief commissioner Angus Mitchell said.
“The fire coincided with multiple unusual indications and a burning smell as the pilot attempted to extend the landing gear.”
In its investigation report, the ATSB noted four other incidents of in-flight fires in Beechcraft Baron planes across Australia and the US, three of which were found to have involved faulty wiring. The agency has issued a warning to operators to inspect their aircraft’s heater fuel line to ensure electrical wiring is not rubbing or chafing against it.
“Damaged electrical wiring can pose a range of hazards to the safety of flight, including loss of electrical power, malfunctioning systems, and in-flight fire,” said Mitchell.
“This hazard is further increased when wiring is proximal to lines carrying flammable liquid. Maintenance organisations and operators should review current practices for the prevention of damage to wiring and ensure that all available steps are being taken.”
The fire ignited in the Baron’s cockpit during its approach to land at Kununurra’s East Kimberley Regional Airport on the morning of 16 April 2022.
Despite expending the contents of a portable fire extinguisher, the fire quickly filled the cockpit with flames and thick smoke, preventing the pilot from effectively seeing external visual references or the aircraft’s instruments.
The loss of visual cues combined with the direct heat of the fire meant that the pilot was presented with significant difficulty retaining control of the aircraft.
The aircraft subsequently diverged from the runway centreline track and collided with the ground, coming to rest inverted about 600m beyond the Ord River and about 800m from the Kununurra runway threshold.
The investigation final report also details findings around the survivability of light aircraft accidents.
It notes the pilot’s four-point harness provided a better restraint and attenuation of impact forces compared to the best available option of a three-point restraint in the rear of the aircraft.
“Four-point restraints, where available, provide increased survivability,” said Mitchell.
“Where available and practical, rearward-facing passenger seats improve frontal impact protection and survivability in an accident.”
