Panel Step/Gap Mismatch Measurement

In phase II we will develop a prototype TD-THz step/gap mismatch measurement system. This system will be able to measure the sub-surface ground-plane step and gap dimensions on the seams of panels on the F-35 aircraft. In phase I, we demonstrated the ability of the TD-THz method to measure the dimensions of the ground-plane step and gap through otherwise opaque boots and coatings. The first application of the Phase II prototype will be in the OEM manufacture of the F-35. Later, the step/gap measurement system can be used in a depot environment to set the step and gap of pre-coated replacement panels, and then eventually by Air Force field service personnel. The proposed TD-THz step/gap mismatch system is based on our T-RayTM 4000 TD-THz instrumentation platform. A major new capability to be developed in Phase II will be a hand-held high speed plug-in TD-THz line scanner with which the operator will inspect the seams. The system will acquire a B-scan across a seam and rapidly calculate the step and gap dimensions. The prototype TD-THz step/gap mismatch measurement system will be tested in the factory environment, demonstrating that it can measure the step and gap on all aircraft seam configurations. BENEFIT: Upon successful completion of Phase II, the proposed TD-THz inspection system will provide the Air Force with a highly capable non-destructive, non-contact, single-side inspection method for the determination of subsurface step/gap dimensions on aircraft doors and panels. The Phase II prototype system will be capable of accommodating all configurations required to be measured on the full-scale aircraft, including the various material suites, joint designs, and contours. The system will have additional applicability to other aircraft which use these coatings and boots.