The investigation into the crash of a small plane in Verdigris in March prompted the engine manufacturer to issue a bulletin to other customers.
The single-engine Cessna 208B turboprop with tail number N106BZ landed near a home a few minutes after 3 p.m. on March 24, 2015.
The pilot, 39-year-old Markus Bastuck, and his passenger, 36-year-old Andrew Anklam, both walked away from the crash with minor injuries.
In its Factual report on the crash, the NTSB said the men had taken off from Tulsa International Airport on a test flight after maintenance had been completed on the plane, when the pilot noticed trouble with the engine.
He determined he couldn't make it back to TIA so he picked the closest airfield to make a forced landing. The plane hit some trees and was badly damaged after touching down near a house.
The NTSB investigator found about 60 gallons of fuel in the plane's tanks, but no fuel in the line from the pump to the engine. The wreckage was then moved to a facility in Dallas where investigators said they could find no problem that would have prevented the pilot from controlling the airplane.
The NTSB said the Honeywell TPE331-12JR engine had been installed on the airplane two weeks before the crash and had only nine hours of running time. Investigators examined it at Honeywell Aerospace and could find no problems with it that weren't caused by the crash.
They did find problems when they disassembled the fuel pump, according to the report. They found wear and material missing from the teeth of the high pressure drive gear, the report says.
The NTSB says the gear was manufactured by Shimadzu, a Japanese company. It was determined, the NTSB says, that Shimadzu used three gears made from 300 series stainless steel instead of the specified M50 steel, which the NTSB says is a harder material.
The NTSB says Honeywell issued bulletins to everyone using engines with fuel pumps with the same part number gear sets as the plane that crashed. So far, the NTSB says the other two gears have not been located.
The Factual report is the second of three the NTSB will release on the crash. The Factual report does not contain conclusions on what caused the crash, just detailed information about what investigators have discovered. The NTSB's conclusion about what led to the crash will be contained in its Probable Cause report, which could take months or even longer to complete.