Abstract:
A technology is in development to provide automated non-contact identification of the presence or absence of cracking, composite delamination, and fatigue damage on H-60 Black Hawk main rotor assembly components. The subject technology design employs passive thermography to capture images of the main rotor blades, rotor hub, and swashplate assembly while the helicopter is in flight, and executes a custom software program to enhance infrared images and detect flaws post-flight. The technology aims to provide selective periodic maintenance and inspection without removal of components from the aircraft or artificial thermal stimulation. In addition to identifying damaged components, the RITS (Rotary Inspection Tracking System) evaluates when maintenance interval or end of life components can be approved for extended use due to absence of damage. Analytical thermal simulations of the blades were developed and a series of flight tests were performed to validate the models and identify thermal heating profiles during flight. A test fixture was utilized to evaluate the detection algorithm functionality by imaging realistic fabricated flaws. Compiled results from the test fixture and on-aircraft testing demonstrate the feasibility of detecting flaws using passive thermography during helicopter flight.