TULSA, Oklahoma -- The federal investigator trying to find the cause of an airplane crash during a wing walking act at a Texas air show last month used a Tulsa company's facilities to examine the aircraft's engine.
Aaron Sauer, the investigator from the National Transportation Safety Board assigned to the case, examined the engine on Monday, April 4, 2011 at Tulsa Aircraft Engines.
Kyle and Amanda Franklin, a husband and wife team from Neosho, Missouri, were hurt in the crash at the Air Fiesta 2011 air show in Brownsville, Texas on March 12, 2011.
YouTube video shows Kyle piloting the 1940 Waco UPF-7 biplane with his wife standing on the top wing, when the engine suddenly loses power and belches fire, forcing Kyle to make a crash landing just seconds later.
According to the Franklins' web site, the plane's engine was supplied by Tulsa Aircraft Engines, located at 9311 East 44th Street North, Tulsa.
The Waco had been retrofitted with a Pratt & Whitney R-985 radial engine. R-985s were manufactured from 1929 to 1953.
Sauer, the NTSB investigator, said he used Tulsa Aircraft Engines' facilities to examine the engine because it is one of the few places in the country that specializes in repairing that type.
Aaron Sauer said the engine from the mishap aircraft still had its propeller and exhaust attached to it, which had to be removed for the examination.
"The engine really wasn't exposed to the fire on the airplane," Sauer said. "The firewall is designed to keep any fire forward of it, but in this case it worked in the other direction."
The fuel system was separated during impact and could not be tested on the engine, he said.
Sauer said the engine's two bottom cylinders, numbers 5 and 6, were damaged by the impact so they were removed and replaced during the examination and the engine ran fine.
The fuel pump also functioned properly, but Sauer did find some issues elsewhere in the fuel system.
"We saw anomalies with the fuel servo," according to Sauer, which regulates the flow of fuel into the engine. "It didn't come within specifications on a couple of settings."
Sauer said his next step is to meet with the company that now supports the fuel servo. It was built by the Bendix Corporation, but the company sold that product line to Precision Airmotive near Seattle in 1988.
He said he can't predict when he'll issue the next report on the crash, a Factual Report, which would be the second of three reports released by the NTSB on the incident.
The Franklins, meanwhile, continue to improve. Kyle Franklin has been released from the hospital. His wife, who suffered 3rd degree burns over more than half of her body, is in the burn unit at the Brooke Army Medical Center in San Antonio, Texas.