Crawling to Safety

Regular jet engine inspections are essential for the safety, reliability, and efficiency of aircraft operations. They are a critical part of aviation maintenance procedures and are carried out at specific intervals, often in accordance with manufacturer recommendations, regulatory requirements, and an airline's own maintenance program. The primary purpose of these inspections is to identify and correct any potential problems or wear and tear that could jeopardize the jet engine's performance or safety.

These inspections involve a comprehensive examination of various components, including the turbine blades, compressors, combustion chambers, and exhaust systems. One of the key tools used in these inspections is the borescope, a flexible optical instrument that allows engineers and maintenance personnel to visually inspect the internal components of the engine without disassembly. Borescopes are equipped with cameras and lighting systems that enable inspectors to capture images and videos of the engine's interior. This technology is invaluable for detecting hidden defects, such as cracks, erosion, foreign object damage, and corrosion, which may not be visible to the naked eye.

Borescopes are valuable tools for inspecting jet engines, but they have some drawbacks. One challenge is that they can be difficult to use in deep, intricate areas of the engine. The flexible nature of borescopes can make it hard to navigate through complex internal passages, especially in larger and more advanced engines. Additionally, gravity can pull the camera off target, making it difficult to maintain a steady view of critical components. Finally, the engine may need to be removed from the wing of the aircraft in order to conduct a comprehensive inspection, which can be a time-consuming and costly process.

A new, worm-like robot from GE Aerospace’s research team called Sensiworm (Soft ElectroNics Skin-Innervated Robotic Worm) may help to alleviate some of these challenges in the future. By using Sensiworm, the engine under inspection can remain on the aircraft. The robot is simply placed in an intake or outlet in the engine, then it crawls around to give maintenance technicians a wealth of information about the internal state of the engine.

Once on the inside, Sensiworm leverages vacuum cups on its underside to keep a strong foothold as it crawls along like an inchworm. A forward-facing camera and lighting system wirelessly transmit a stream of live video for inspectors to examine for cracks or other problems. The robot is also outfitted with an array of sensors to provide valuable information — a gas sensor alerts inspectors to possible leaks, and there is also equipment onboard that is capable of measuring the thickness of thermal barrier coatings. GE Aerospace plans to include additional sensing capabilities on a future version of the device.

As it currently stands, Sensiworm is tethered to an external power supply for energy and computing resources for control. Needless to say, this wiring could quickly become a problem as the robot snakes its way deeper and deeper into a jet engine. Accordingly, the team is presently working to cut the cords so that Sensiworm will be fully self-contained, with its own source of power and computational resources.

This extra set of eyes deep inside of jet engines could give inspectors a big boost in maintaining safely operating flight equipment, if the researchers can push the prototype forward and produce a finished product, that is. And if they achieve that goal, they have even bigger plans for Sensiworm — looking beyond inspections, they envision a future version of the robot being able to make repairs. Perhaps that will eventually lead to a future with fewer flight delays, and that is something we can all get excited about.