Air Force News

Air Force, industry team up for quick retrofit of C-17 landing gear

Released: 16 Dec 1999

by 1st Lt. Dave Huxsoll
Aeronautical System Center Public Affairs

WRIGHT-PATTERSON AIR FORCE BASE, Ohio (AFPN) -- The Air Force, Boeing, and two Ohio companies have teamed up to dramatically reduce the time needed to retrofit landing gear on some C-17 Globemaster IIIs.

The C-17 System Program Office here, along with the Boeing Company and subcontractors Eagle Tool and Machine Company, Springfield, Ohio, and BF Goodrich Aerospace, Cleveland, came together and accomplished in just two months what was originally scheduled to take 16 months.

The first 39 of the 56 C-17s in the inventory were delivered to the Air Force with an undetected design flaw that led to premature failures of the trunnion collar, a component of the main landing gear which guides gear rotation up and down. The trunnion collar attaches the main landing gear post to the fuselage.

Durability testing failure in February 1997 showed the original trunnion collar design would not last for the full 30-year service life of the C-17. Since this test regime was leading the actual fleet usage rate, starting with aircraft number 40, all new aircraft have re-designed forward main landing gear trunnion collars. A retrofit program was established for the original 39 aircraft.

Retrofits were to be completed December 2000 and 17 aircraft had already received the re-work. However, this summer Air Mobility Command and the C-17 SPO decided to accelerate this program.

"It was decided in July to expedite the entire process." said Col. Ted Bowlds, C-17 SPO director. "There were 22 aircraft that still needed the trunnion collar retrofit, so we put together a team and established a plan to complete the program in approximately 18 weeks. With innovative management ideas, procedures and dedication, the team was able to complete that activity in a little over eight weeks."

The one ground rule was to avoid impacting current production requirements. BF Goodrich, as the overall landing gear subcontractor for the aircraft, and Eagle Tool, who is responsible for machining all trunnion collars, developed a process plan that expedited re-work parts through their shops without impacting their current production runs.

The first step in the re-work process was for Eagle Tool to machine the trunnion collars. These were then delivered to BF Goodrich, where the remaining process and assembly work was completed. Eagle Tool revamped their work-in-process flow, eliminating potential conflicts between production and re-work efforts.

Two retrofit "speed lines" were set up by Boeing to remove and replace the trunnion collars on the affected aircraft -- one at the Boeing Aerospace Support Center in San Antonio, and one at Boeing's factory in Long Beach, Calif. Installation on each aircraft, originally planned to require seven days, took only three days to complete.

"It was a truly team effort," Bowlds said. "For instance, BF Goodrich sent one of its heat-treating ovens to Eagle Tool to help expedite the effort, and the Air Force Research Laboratory made available a horizontal milling machine from its modification shop. This allowed the company to operate both production and re-work process lines. Everyone played a part in making this happen. It epitomizes what an integrated product team is all about."


* C-17 Globemaster III
* Aeronautical Systems Center