NTSB: Tom Tiffany’s Ditched Bonanza Had an Empty Left Tank and Three Full Ones

The engine of the Beechcraft Bonanza N6071E, which ditched in Lake Wausau, Wisconsin, on September 12, 2026, with US Rep. Tom Tiffany aboard, did not respond after its pilot switched fuel tanks in the landing pattern, according to the NTSB’s preliminary report. Investigators found the left main tank empty and the right main and both auxiliary tanks full.

The report, case CEN26LA319, was filed on October 13, as the Milwaukee Journal Sentinel reported. It sets out the facts gathered so far and does not state a cause.

What happened over Lake Wausau

The 1959 Beech K35, registered in Pearson, Wisconsin, according to the FAA aircraft registry, left La Crosse Regional Airport about 8:15 p.m. for Wausau Downtown Airport, the NTSB said. Tiffany, a Republican running for governor, was returning from the La Crosse County Lincoln Day Dinner in Onalaska with pilot Leonard Boltz, 73, Wausau Pilot & Review reported, citing the Marathon County Sheriff’s Office.

The pilot told the NTSB that in the traffic pattern, shortly after he lowered the landing gear abeam the runway threshold, he saw a higher-than-normal exhaust gas temperature. That reading reminded him to switch tanks.

He selected the right tank and pushed the mixture and throttle fully forward, but the engine did not respond. He said he did not turn on the electric fuel boost pump while trying to restore power, then turned toward the runway and prepared to land on the water.

The airplane hit the lake at about 8:49 p.m. on a clear, dark night, damaging the fuselage, left wing, left aileron and engine mount. Both men got out and had minor injuries, and a Wausau Fire Department airboat reached them at 9:05 p.m., according to Wausau Pilot & Review.

Where the fuel was

According to the pilot, the Bonanza flew two legs that day without refueling. He said it left Langlade County Airport in Antigo with 70 gallons (265 liters) aboard, and that he kept the left main tank selected on both legs apart from brief switches to the auxiliary tanks in cruise.

After the airplane was recovered from the lake, investigators found every fuel cap secure. The table sets the fuel the pilot reported at departure beside what the examination found.

Tank	At departure from Antigo (pilot’s account)	Found after the accident
Left main	25 gallons (95 L)	Empty
Right main	25 gallons (95 L)	Full
Left auxiliary	10 gallons (38 L)	Full
Right auxiliary	10 gallons (38 L)	Full

The cockpit controls matched the pilot’s account. The fuel selector was on the right main tank, the throttle, mixture and propeller levers were nearly full forward, and the boost pump switch was off.

The report also records a second-hand account. In an interview with an FAA inspector, the pilot’s mechanic said the pilot had told him the power loss was due to his delay in switching tanks and not turning on the boost pump.

Why fuel on board does not always reach the engine

Fuel-related accidents rank among the top ten accident categories in general aviation, by the NTSB’s count for 2011 to 2015, and two causes lead them. In an NTSB safety alert, the board defines fuel exhaustion as running out, and fuel starvation as having fuel on board that does not reach the engine, for example because of a wrongly set fuel selector.

That 2017 alert counted more than 50 fuel-management accidents a year from 2011 to 2015, and starvation accounted for 35% of fuel-related accidents. It found that 95% of the investigations cited personnel issues, such as how equipment was used, and fewer than 5% a failure of the fuel system.

The fuel selector itself is a recurring factor. A 2018 NTSB alert said the board had cited it in 104 accidents since 2008, 63 of them involving incorrect use.

N6071E carried its fuel in four tanks, and the pilot chose which one fed the engine with the fuel selector valve. The 2017 alert’s advice to pilots is to know how much fuel is aboard at all times, know the airplane’s fuel system, and use the checklists.

Whether any of that applies to this flight is for the investigation to decide.

What happens next

The NTSB classed the case as a Class 3 investigation and did not send investigators to the scene, according to the report. An FAA representative based in Milwaukee is also taking part.

Like the board’s Carlisle midair report, this one adds detail without a cause. The NTSB determines a probable cause at the end of an investigation and publishes it in the final report.