Rolls-Royce are synonymous with safe and reliable power, and produce the world's most efficient aerospace gas turbine engine. To maintain safety and efficiency, Rolls-Royce perform routine inspection and servicing of their engines throughout its lifecycle. As engines wear, the most critical components may show signs of deterioration that may lead the engine to be removed from service ahead of its next scheduled overhaul. To address these challenges, and to maximise engine availability and time on-wing, Rolls-Royce continues to lead the way in the development of in situ inspection and repair techniques. Such tools can be deployed via a range of access holes (or "borescope ports") across the side of the engine, and navigated to the area of interest. Once there, a range of inspection and maintenance tasks can be performed by a highly-skilled mechanic, such that the engine can be safely returned into service. Due to the geometrical restrictions, and the required dexterity and capability of the tools, this approach is analogous to keyhole surgery.

THEMIS (THickness Evaluation and Measurement In Situ) aims to increase Rolls-Royce's portfolio of in situ inspection techniques. In particular, the aim is to develop a process that can measure the thickness of components and coatings when the engine is still intact and installed. This will allow an even more in-depth understanding of the integrity of the asset, and thus allow the mechanic to determine whether further maintenance is required or if the engine is safe to fly-on. THEMIS is highly challenging project, but would help to develop a technique that would have a significant value to the Rolls-Royce Aftermarket Services team.