N333BMBarber Robert L SONERAI II L · 1987

On April 03, 2022, at 1310 Pacific daylight time, a Sonerai II L, N333BM, sustained substantial damage when it was involved in an accident near Jean, Nevada. The pilot sustained serious injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The pilot stated that he departed from Kingman, Arizona, with the intention of landing at his home airport in North Las Vegas, Nevada. Before the flight, he added 3.8 gallons of fuel, but did not know the total amount of fuel on board at the time of departure. While en route, the pilot opted to divert to Jean, Nevada, because of the gusty wind conditions in Kingman. During the flight, he noted that there were strong headwinds but thought he had adequate fuel for the flight. When arriving in the proximately of Jean, the pilot made a low pass over the airport to evaluate the wind conditions. While maneuvering to land on runway 20, the engine sustained a loss of power. The pilot was unable to maintain altitude and the airplane collided with the desert terrain about 0.5 miles north of the approach end of the runway.

The Clark County Fire Department responded to the accident site. Fire department personnel stated that a visual examination of the fuel quantity indicator showed the fuel tank was empty. This was confirmed by opening the fuel cap, visually examining the inside of the tank, and then inserting a dipstick.

The airplane's fuel system was a gravity-fed design where fuel flowed from an aluminum 10-gallon tank mounted in front of the instrument panel. Inside the tank there was a finger screen at the outlet and at the top of the tank was a vent output port. The port connected to a T-fitting where one clear plastic tube was routed to the instrument panel and back to the bottom of the tank. On the tube was a series of different colored tie-raps that served a fuel quantity indicator for the pilot (see Figure 1 below). The other tube on the T-fitting was routed to the bottom of the airplane and functioned as a vent. From the fuel tanks, the fuel was routed to a fuel shutoff valve and then through several fittings through the firewall to a gascolator (mounted on the engine-side of the firewall). The fuel would then continue to a fuel injector unit, where it was routed from the inlet through an orifice to the air inlet. From the inlet, the fuel-air mixture continued into the intake manifold and into each cylinder. A majority of the fuel pipe fittings had Teflon tape on the threads.

Figure 1. Fuel System

A postaccident examination revealed that there was no fuel onboard the airplane. The entire system remained un-breached except where the gascolator drain was compromised. The gascolator was clean and no debris was in the screen. The tapered fuel needle remained in the fuel orifice and the throttle slide was in a partially open position, consistent with near full throttle.

During a postaccident examination, investigators achieved manual rotation of the crankshaft by rotation of the remaining propeller blades. Valvetrain continuity was observed, with equal lift action at each rocker assembly; oil was found in the rocker box areas on all cylinders. Investigators removed the upper spark plugs of all cylinders and they were light gray/white in color, consistent with lean to normal engine operation. A borescope examination of the cylinders revealed no foreign object damage, no evidence of detonation, and no indication of excessive oil consumption. The exhaust manifold pipes showed white residue consistent with a lean mixture.

The magneto timing was consistent with normal operation. The upper spark plugs were reattached to their respective lead and rotation of the crankshaft resulted in a visible spark at each plug; the impulse couplings were audible during rotations.