May 5, 2003 (by 1st. Lt. Garrett Grochowski) - America's premier multi-role fighter is slipping into some tougher armor at the Ogden ALC. When the Service Life Improvement Program modification is complete, it will extend the life of the F-16 by about eight years.
"This mod is all about extending these aircraft - putting them back up to get more life out of them," said Gary Grivet, F-16 Branch module chief.
SLIP was started about five years ago to repair the cracks in high stress, fracture critical and potential crack areas. These areas were created over time when stress on the airframe was transferred to other areas after the Falcon-Up, an earlier structural modification program, was started.
During Falcon-Up, technicians replaced some of the bulkheads, reamed the fuel shelf boltholes and replaced some of the Falcon's other segments. Over time, this caused the other unenhanced areas to start cracking. This in turn led to the start of the SLIP program.
"SLIP Mod is the modification of the upper fuselage area, which beefs up the exterior of the aircraft where cracks have or may occur from years of wear and tear," said Grivet.
The SLIP mod, or 2060 modification, replaces the old bulkheads with new composite metal bulkheads, the entire engine mount, fuel tank panels and fasteners as well as other structural components. These repairs and replacements take care of the cracking problems on the aircraft"s aluminum alloy panels.
From the time it gets here to when it leaves is 94 days, depending what other mods need to be done. F-16's that are here for the SLIP modification are on the production line for 52 to 56 days.
"Which upgrades we do depends what"s on the work order and the total number of flight hours on the aircraft," said Grivet. "Whatever upgrade's being done will be on the contract request form that tells us whether we only have to do a SLIP mod or avionics upgrades as well. The aircrafts' units will also find stuff that they want done."
When the aircraft comes in, its fuel and engine have already been removed. It's jacked up and then It's then stripped. After that, all the panels are taken off, and the new composite panels are installed. All the components are then checked by an NDI (Non-destructive Inspection) to ensure that there are not any cracks that are too small to be seen by the naked eye.
After structural mechanics accomplish their mods, F-16 Branch technicians rebuild everything, putting it all back the way it was when the plane arrived. For SLIP, as for every mod, there"s a kit to provide everything the F-16 branch needs.
"We reassemble it and then run it back through the fuel facility, where aircraft parts are checked for proper operation and any leaks. From there the Falcons are taken to flight test where the engine"s put back in."
It takes a team of six or seven to complete work on an aircraft. This breaks down to three aircraft mechanics and three or four electricians, working in a two-shift operation.
"Right now we're working on modifying three blocks of F-16"s, the 25, 30 and 32"s with SLIP upgrades," Grivet said. SLIP upgrades have already been made to the newer block 40
and 50 F-16"s, which are now going through CCIP
"A lot of what we do depends on what other upgrades we're doing," said Grivet.
Often times along with the SLIP structural enhancements, because of leaks and structural problems, the wings need to be removed and sent to the wing shop. Leak checks are then done at the fuel barn.
"Sometimes, when we have the aircraft all broken down, we"ll find stuff the unit didn"t see. If It's a safety of flight issue, we'll always fix it, but if It's not we"ll call the aircraft"s home unit and see what they want done."
A lot of the repairs the F-16 branch does depend on what's found by both the aircraft"s home unit and Team Hill. Some aircraft have more wear and tear because of number hours their units fly and the environment at the aircrafts' home base, such as humidity or salt in the air.
"The more high-tech you go the more complex a modification gets. We have good mechanics, a lot of talented people, with a lot of experience on this airplane, which makes the job go really well and keeps us on schedule," said Grivet. "Lots of times we go ahead of schedule. And that's all because of the people on the floor."