Fusion splice repair passes field tests Published Sept. 16, 2019 By R. Nial Bradshaw, 75th Air Base Wing Public Affairs HILL AIR FORCE BASE, Utah-- The Air Force Sustainment Center and Air Force Research Laboratory worked with the 309th Aircraft Battle Damage Repair and Expeditionary Depot Maintenance team at Hill Air Force Base, Utah, from Sept. 9-12 to test the feasibility of a new fiber optic fusion splice repair technique for fifth-generation aircraft. The field test demonstrated that a trained maintainer with the proper equipment can perform an acceptable fusion splice repair on an aircraft in roughly 20 minutes, once the damaged section is isolated and made accessible. The current practice of replacing a damaged fiber optic cable can take hours and sometimes days. “The process was simple and easy to learn,” said Tech. Sgt. Kenan Harvey, 309th Aircraft Battle Damage Repair and Expeditionary Depot Maintenance avionics technician. “Fusion splicing could be a very viable solution for fiber optic repair for aircraft battle damage, and eventually at the field level.” The small size of the fusion head used for the test allows it to go practically anywhere and to splice whether level, vertical, sideways or upside down. Harvey was trained on the fusion splicer by Laurence Wesson, president of Aurora Optics. The company also makes an explosion-proof version to operate in hazardous atmospheres, including fueled aircraft. A total of eight fusion splice repairs were made, and they all met the minimal signal loss requirements when measured. Two splices were made on an F-35A Lightning II and one was made on an F-22 Raptor. Signal loss is measured in decibels and the test splices averaged less than .02 dB where .5 dB is the maximum allowed. At .02 dB, a single run of cable could feasibly be spliced 25 times and still meet performance standards. The next step in getting this repair capability to maintainers is the environmental testing of the splices by the AFRL’s Materials and Manufacturing Directorate. “The lab will run the splices through a series environmental stresses such as temperature shock, thermal cycling with humidity and condensation, chemical and vibration exposures,” said Edward White, AFRL materials engineer. “This technique is very promising. We hope that the environmental tests go well and that this approach passes,” said Brett Jordan, AFRL electrical engineer. Fiber optics are found not only in the Air Force’s most advanced aircraft, but are also present in most legacy aircraft. “This is a cross-cutting capability. Fiber optics doesn’t discriminate whether you’re on an F-35, B-52 or an F-22. Even combat communications could use this capability,” said Senior Master Sgt. Mike Reid, AFSC Aircraft Battle Damage Repair Functional Area Manager.