F-15 maintainers work to replace faulty longerons
By Wayne Crenshaw , 78th Air Base Wing Public Affairs
/ Published November 14, 2008
ROBINS AIR FORCE BASE, Ga -- In hangars on the Robins flightline, F-15 Eagle fighter jets can always be found in varying states of disassembly.
Removing and replacing parts is something that's done every day here. But some parts, like a longeron, are never meant to be removed. A team from Robins was tapped in June to figure out how to replace faulty longerons in grounded F-15s, and thanks to their efforts the planes will fly again.
"By the expertise of all these guys in these respective fields, they were able to put the plane back to flying status," said David McNeal, flight director in the F-15 Wing Repair Flight. "It's a credit to their professionalism and the workmanship they were able to accomplish this. This was the first time this removal and replacement had been done on an aircraft."
A longeron is a 12-foot long aluminum beam that is an integral part of the F-15S's structure, tying the front and rear fuselage together. It's so important that a cracked longeron was blamed for a crash of an F-15 in Missouri a year ago. The plane split apart in mid-air, but the pilot safely ejected. Several F-15s with cracked longerons are still grounded.
In June, a team from the 402nd Maintenance Wing got the task of trying to figure how to remove and replace the top longeron, which runs horizontally along the top frame of the cockpit. It's the piece on which the canopy rests. The team, led by Odell Norwood, was made up of personnel in varying areas of expertise, including Larry Smith, Walter Tanner, Russell Thompson, John Allison, and Darren McLeod. Mr. Allison, a sheet metal mechanic in the Wing Repair Flight, was credited with establishing the protocol for the removal and replacement of the part. His efforts earned him a nomination for a quarterly achievement award.
The team traveled to St. Louis, Mo., in June and spent three weeks working out how to remove and replace the longeron. The process included the use of optical equipment to precisely record how the piece fit in the plane to start with so it could be replaced exactly as it was. The team also had to painstakingly remove numerous other parts, including electronics which interfered with the removal.
The longeron team took a new longeron -- manufactured at Robins from the original blueprints -- to St. Louis with them, but when they installed it they determined it needed some adjustments. So they returned to Robins while the adjustments were made and went back to St. Louis in August to install the longeron again.
This time it worked perfectly and it checked out in a recent flight test. Now the protocol established by the team will be used to replace the faulty longerons on other grounded F-15s.
Mr. Norwood said he was pleased with how the team dealt with the unique challenge.
"We feel like we worked pretty good together," he said. "We all filled in and helped each other."