A report released this week regarding the Wright ‘B’ Flyer crash that killed two local test pilots last year said incomplete penetration of metal welds on the experimental aircraft’s propeller shafts are under scrutiny.
However, a probable cause for the crash has not yet been released by the National Transportation Safety Board regarding the July 30, 2011, crash of the experimental “Silver Bird,” which resulted in the death of volunteer pilots Don Gum and Mitchell Cary.
A lab report indicates welds to the propeller shafts were not complete, as required by manufacturing.
“Approximately 25 to 35 percent of the through thickness of the propeller shaft tube had not been joined to the propeller shaft end,” according to the National Transportation Safety Board Materials Laboratory’s analysis of both shafts.
The left propeller shaft had completely separated and the right propeller shaft exhibited a fracture along their rear welds, but it was not immediately clear if the separation and fracture happened before or after the crash.
Visual defects such as pores and voids were also observed in the fractured areas, and incomplete weld penetrations were found in other welds along the shafts.
“Silver Bird” operator Wright B. Flyer Inc. President Phil Beaudoin confirmed Thursday the report focused on propeller shaft welds.
“As you can see from the material laboratory’s report, we had prop shaft weld problems,” Beaudoin said. “I’m not going to divulge where they came from, but it was contracted out.”
The company flies one other Wright Flyer look-a-like, the “Brown Bird,” that’s been in operation since 1982. It’s propeller shafts do not have the same setup as the “Silver Bird” and are examined on a yearly basis, Beaudoin said. The “Silver Bird” was still in its flight testing phase when it crashed.
“We’re looking at (the report) in detail, and we will take any actions necessary,” Beaudoin said.
As for the “Brown Bird,” the company continued its flyovers and orientation rides during the summer. “We are continuing business and continuing flying,” he said.
Also presented in the report released Tuesday are known facts from variety of indicators including the pilots’ flight careers and medical certifications, on-board flight data, weather and witness statements.
Investigators found Gum, 73, of Beavercreek, and Cary, 64, of Yellow Springs, were both certified as commercial pilots and had more than 300 hours of combined flight time in the same make and model as the crash airplane and more than 4,030 of total flight time.
They died of blunt force injuries, according to a coroner’s report.
An analysis of an engine monitor and GPS unit on the airplane indicates the engine’s RPMs, oil and manifold pressure, and fuel flow fell dramatically at 10:41:30 a.m., just a few seconds before GPS data recorded a dramatic loss of altitude leading to the crash about 3½ minutes later.
It crashed seconds before 10:45 a.m. in a field about a mile west of 7391 Pitchin Road, nearly 40 minutes into a test flight originating from Springfield-Beckley Municipal Airport.
A high definition video camera showed that plane yawed near the end of the recorded video. Both pilots were observed to manipulate controls following the yaw, and it showed the plane was controllable.
Several witnesses in the area reported hearing the airplane’s engine sound as though its RPM varied and observed it to be flying slow and banking to the left and right just before the crash. One witness reported that it spiraled downward.
An NTSB spokesman in Washington, D.C., did not return a Springfield News-Sun call on Thursday seeking more information.
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