On Feb. 6, 2023, an RV-6 was substantially damaged when it was involved in an accident near Milton, Florida. The airline transport pilot was seriously injured.
According to the pilot, he was relocating the airplane following completion of its annual condition inspection.
He reported performing a thorough preflight inspection that included sampling the fuel, with no contaminants noted, checking the oil, which was full at 8 quarts, and checking the tires and brakes, which were new.
He also reported that the left fuel tank was indicating about 7 gallons of fuel and the right fuel tank was almost full.
Nothing abnormal was observed during the preflight, engine start, run-up, or taxi.
The pilot positioned the fuel selector to the right fuel tank before taxiing to the runway. Shortly after takeoff, during the initial climb about 300 to 400 feet mean sea level, the engine “let out a muffled, sucking backfire” and sustained a total loss of power that was confirmed by multiple eyewitnesses.
The pilot pushed the nose over abruptly to maintain airspeed and made a Mayday call reporting the loss of engine power over the airport’s common traffic advisory frequency.
During descent, the engine regained power shortly before the plane hit the ground.
A witness was taking a video of the airplane during the flight and the video confirmed the increase in engine power several seconds before impact.
The airplane hit the ground and a fuel truck before coming to rest.
Post-accident examination confirmed the fuselage, tail section, and wings were substantially damaged.
Post-accident examination also found no anomalies except that the fuel pickups in both wing tanks were not installed correctly when compared to the plans for a Van’s RV-6.
The plans called for the fuel pickups to be routed down towards the bottom of the fuel tank and then bend toward the aft bulkhead of the fuel tank, under the fuel sending unit.
The fuel pickups on the accident airplane were routed down and then bent forward toward the leading edge.
The kit manufacturer reported that if the fuel pickups were bent forward toward the leading edge instead of aft, as the plans called for, then the amount of unusable fuel would greatly increase.
The pilot (who was the third owner of the airplane and not the original builder) reported that there was no documentation stating the amount of unusable fuel, only that the fuel tanks had a total capacity of 38 gallons.
The investigation was not able to determine the amount of unusable fuel due to the selected fuel tank being compromised in the accident sequence. A “Flying Lessons” article published by the FAA on May 26, 2011, discussed how fuel moving away from the fuel tank pickups could result in fuel starvation and a loss of engine power.
A review of maintenance records showed that service bulletin SB 06-2-23 and a service notification letter issued June 12, 2000, from the kit manufacturer, relating to the fuel pickups, had not been complied with.
The publication Service Bulletins and the Aircraft Owner, published by the FAA, states, “Manufacturers issue aircraft Service Bulletins to inform owners and operators about critical and useful information on aircraft safety, maintenance, or product improvement,” and “If you are operating your aircraft under 14 CFR part 91, a service bulletin is advisory, and compliance is not mandatory unless it is included in an Airworthiness Directive.”
A search of the FAA Dynamic Regulatory System found no airworthiness directives for the Van’s RV-6.
Probable Cause: The incorrect installation of the fuel pickups, which resulted in a total loss of engine power due to fuel starvation. Contributing was the lack of documentation of the airplane’s unusable fuel.
NTSB Identification: 106687
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This February 2023 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
