Grease, oil and other contaminants can degrade the efficiency of fiber optic cables to transmit data to avionics and flight control systems, and the fiber stands must be cleaned to ensure that light can pass uninterrupted through the cables.

Advanced military aircraft rely on fiber optics to transmit massive amounts of data to avionics and flight control systems in real time. Like most other parts of an aircraft, the connectors at the ends of these critical cables and the ends of the fiber strands inside the connectors can get dirty with use in harsh environments, which can degrade their efficiency.

Currently, aviation maintenance professionals at Fleet Readiness Center East (FRCE) use a manual process to clean grease, oil, dirt, and other contaminants that degrade the cable efficiency to ensure that light passes uninterrupted through the fiber strands inside of these cables. This process essentially runs a piece of floss across the end of each fiber strand one at a time to clean them, according to Chase Templeton, Robotics, Support Equipment, and Wiring Technology Lead for FRCE’s Advanced Technology and Innovation (ATI) Team.

“Right now, we’re using a manual process in which you have to align the cleaning tool perpendicular to the face of the fiber optic cable connector, and the positioning of the tool dictates how clean you actually get the fiber strand,” Templeton said. “It’s time consuming and may take as many as three to five cleanings before each fiber strand is completely clean.”

That’s why the ATI Team recently hosted a demonstration of a robotic fiber optic inspection and cleaning system that has been used successfully in an aircraft manufacturing environment. Engineers and maintenance professionals from a number of platforms attended the demonstration to see how effectively the system could clean the cables in aircraft maintenance environments.

Templeton said the advantage of a robotic system is that it takes the guesswork out of aligning the cleaning tool with the fiber optic cable.

“With the robotic system, it perfectly aligns the cleaning floss to the fiber strand end every time,” he said. “It usually only requires a single cleaning to meet specifications for cleaning those fiber optics.”

Representatives from FiberQA demonstrated their robotic fiber optic cleaning and inspection system on FRCE’s F-35 Lightning II maintenance trainer airframe to an audience of about 20 FRCE participants. Doug Wilson, founder of FiberQA, called the robotic system a first line of defense against contamination of the fiber optic cables.

“There are two parts to it. One, make it clean enough so it actually transmits the light to maximize the efficiency of the network,” Wilson said. “The second is to prevent damage due to that contamination. Our equipment verifies that it’s safe to connect.”

FRCE engineers who attended the demonstration said removing the human factor from fiber optics cleaning would be beneficial to the rework process.

“It’s a highly subjective task and requires a lot of training to be able to inspect and clean our fiber optics effectively,” said Matthew Crisp, F-35 Joint Program Office site lead at FRCE. “We want to see what opportunities we have to remove the subjectivity and increase the speed of doing those inspections.”

The robotic cleaning and inspection system from FiberQA is used currently in aircraft manufacturing environments, but the company is looking to expand into aircraft maintenance. The next step for the ATI Team is to determine what changes might be necessary for the technology to be useful in the maintenance operations for the F-35 platform or any other platform that utilizes fiber optic systems.

“We don’t want equipment that can be easily damaged, and we don’t want a lot of weight hanging off the aircraft connectors. Any extra weight that is hung on these wiring harnesses is not a good thing,” Templeton said. “We need to find a way to support this new tool, and we need to make sure it’s ruggedized enough to be used in a depot environment.”

FRCE is North Carolina's largest maintenance, repair, overhaul and technical services provider, with more than 4,000 civilian, military and contract workers. Its annual revenue exceeds $1 billion. The depot provides service to the fleet while functioning as an integral part of the greater U.S. Navy; Naval Air Systems Command; and Commander, Fleet Readiness Centers.