Life extension programs generally include various upgrade kits and improved replacement parts. New avionics, new engines and oft times replacement wings fill out the order along with a raft of maintenance/inspection procedural changes. The original airframe is usually left intact - without major modifications or replacements. In order to maintain the aging fuselage, a new series of inspection routines are necessary. The call for advanced and novel inspection technologies has brought together many technologies: each with their own strengths and weaknesses.
This paper addresses the introduction of the D Sight Aircraft Inspection System to the fuselage inspection protocol of the Royal Air Force (RAF) aging aircraft fleet. The RAF is developing a Three Tier system of lap seam and butt joint inspection, which exploits the strengths of distinct technologies. The implementation of this three-step program begins with the speed and organization capabilities of the optical system D Sight Aircraft Inspection System (DAIS). Using a fuselage mapping system, DAIS pre-plans lap joint inspections and subsequently track data acquisition and analysis through colour coding. D Sight corrosion signatures appear as bright-to-dark grayscale contrasts in a halo effect around lap seam rivet heads.
The instantaneous nature of the digital images and the ability of DAIS to capture substantial volumes of data in a short period of time provides RAF inspection personnel with corrosion indications of where to apply the second tier methods, either MAUS or AndScan. Should the need arise, the application of any other method of detection, possibly Mark 1 eyeball or even radiography, would fill out the third tier.