Regular maintenance on H-53 rotary wing aircraft involves hazardous, time-consuming work. Each aircraft has seven composite blades that require regular resurfacing to ensure balance and proper coating to prevent cracks and corrosion. It can take maintenance artisans approximately 24 hours to carefully sand away the top layer of paint and the primer while carefully avoiding damage to the underlying composite substrate. Not only is this task time–consuming and tedious, but it also creates a hazardous environment. Small dust particles generated during the sanding process contain heavy metals such as the hex chrome used in corrosion-resistant paint. Consequently, artisans are required to wear a respirator and a full personal protective equipment (PPE) suit to prevent self-exposure.
But a safer, greener option now exists. The Automated Rotor Blade Stripping System (ARBSS), which uses a Lasertronics laser, was first demonstrated to the Navy recently through the CTMA program. It uses robotic laser ablation, an innovative method that safely and effectively removes the topcoat while protecting the primer coat, which prevents damage to the composite blade.
The system uses pulse-by-pulse closed-loop control technology to strip coatings and capture all stripped particulate material in a HEPA filter. The process is much quicker and safer than older methods. The laser burns off all the organic compounds in the paint, leaving just the heavy metals and other hazardous material to be captured in the filter. This system significantly reduces the amount of contaminated dust when compared to sanding, which supports the DOD’s priority of environmental responsibility.
“With the ARBSS there are significant time savings and it removes the potential for a repetitive motion workplace injury or hazardous material exposure,” says Steven Lofy, Materials Engineer at the Fleet Readiness Center-East at Cherry Point, North Carolina (FRC-E). “Now the artisans require no PPE because they are sitting in a control room behind laser safety glass.”
The technology continues to advance. Now sensors in the ARBSS have been modified to improve their ability to detect each layer of paint by automatically recognizing certain colors. The system can scan the blade, orient itself, and perceive each paint layer’s color on the blade. Because the topcoat and primer are different colors, the technology detects each through its particular red or blue wavelength configuration. This color recognition allows the artisan to select which color to strip and which to leave, thereby making sure they stop once the primer is exposed.
“Each time we successfully sustain these rotary blades, we extend the life of the aircraft,” says Chase Templeton, Advanced Technology & Innovation (ATI) Robotics Technology Lead at FRC-E. “We are working to get the ARBSS approved for other air platforms, which will enhance reliability and operational readiness across the fleet.”