Advanced Technology in Video Borescopes Keep Aircraft Safely Flying

Oct. 16, 2008
Advances in technology have significantly improved the quality and performance of remote visual inspection in aviation inspection, particularly with video borescopes.

RVI, digitization, and wireless connectivity are helping airlines operate efficiently and maintain fleets cost effectively

Like many industries, commercial aviation is facing numerous challenges due to the current economic climate, rising costs, and global competition. For aviation companies of all sizes, operating as efficiently as possible and maintaining fleets cost effectively is as critical as passenger safety.

Airlines cannot afford to have their aircraft on the ground for lengthy inspections or time-consuming maintenance; they need to employ the most reliable, advanced technology available to quickly and easily complete inspections and reduce downtime.

For example, conducting scheduled maintenance with remote visual inspection (RVI) is a cost-effective and increasingly efficient way to keep aircraft safely flying. RVI helps maintenance experts inspect and capture images in inaccessible locations such as engine chambers or other internal areas of the aircraft. RVI operates as a stand-alone inspection technique or to identify areas that require further nondestructive testing or evaluation (NDT/NDE.) It is often used for root cause failure analysis.

Advances in technology have significantly improved the quality and performance of RVI in aviation inspection, particularly with the introduction of video borescopes in the 1980s. Whereas traditional borescopes rely on hard optic relay components to transfer the image to the tip of the eyepiece, video borescopes use charged couple device chips (CCDs), commonly found in digital cameras, at the end of a thin, flexible probe to capture still and moving images. Capturing and storing images is a major improvement over the previous technique, which required analysis by the technician based on what was seen through the small aperture.

Full articulation allows maintenance crews to navigate the probe by simply using a joystick, allowing access to and inspection of difficult-to-reach areas that were once too small or too dangerous to access. High quality still images and videotape are captured and stored; defects are measured. Millions of hours of data about the engines can now be collected, helping engineers better understand the operation and the limits of the system, thus increasing future reliability and safety.

Early models of video borescopes were cumbersome and involved extensive wiring, complex setups, and bulky equipment. Wires created a safety issue in the work environment; technicians were in danger of tripping, becoming tangled, or getting electrocuted if the wires came in contact with water. Inspections had to take place where there was accessibility to electrical outlets. Viewing areas were limited by where the probe could reach. What was reported relied on the technician’s interpretation. Observations had to be translated into drawings on paper, measured, and then manually written into a report.

Today, video borescopes are smaller, flexible, more portable, and easier to use. Image quality is significantly enhanced. For example, smaller, more powerful light engines have increased light output to more than 200 lumens for some models. Imager pixel counts have nearly doubled from 240K to 440K, resulting in images with greater resolution, which facilitates defect recognition. Technicians can see sharper details with greater magnification at a higher resolution and with less interference. Wireless connectivity makes it easier to maneuver the unit to look for damage to an engine, whether it is caused by normal wear and tear or foreign object debris (FOD). They can also easily enhance details if necessary using digital processing and perform immediate analysis.

“We’ve had portable video borescopes in place for a while, but what we really needed was the technology enablers to make them self-contained and unitized – that is to say, like a cordless power tool,” says Joseph Lopez, senior product manager, GE Sensing & Inspection Technologies. “We were able to borrow from the rapid advancements being made in the consumer electronics industry with products like digital cameras and mobile web devices. Image quality is critical to the customer, so the portable unit, while easier to use, would have been useless without the high quality video display and advanced features such as storage, playback, and defect measurement.”

There are added safety benefits as well. No wires and extension cords make the work environment safer. Technicians no longer need to worry about tripping, getting tangled up in scaffolding, or having a cord fall into a puddle of water. Inspections can be done anywhere; the aircraft do not need to be located near electrical outlets. Portable units can even be kept aboard certain aircraft for on-the-spot inspections.

“The new technology is all about not being tethered to a work space and still getting an excellent image and all the features we’ve come to expect in a video borescope,” says Lopez.

Another game-changing technology that is still evolving is the impact of digitization. The combination of technology advances like connectivity through Wi-Fi and Ethernet, USB, and DVD media, and desktop access manuals are helping to create additional possibilities for inspection productivity and data management. An example of this is menu-directed inspection (MDI). MDI provides a guided inspection imported onto the borescope or other diagnostic device, ensuring consistent inspection by operators of all skill levels. In addition, context is automatically added to images, enabling technicians to click-to-report, improve quality, save time, and improve the decision process. With MDI, technicians follow a step-by-step process displayed on the screen of the borescope that instructs them on what to do and what to capture.

“It’s the next thing,” says Christine Murner, aerospace marketing leader, GE Sensing & Inspection Technologies. “Digitization enables many paradigm shifts, such as menu-directed inspection, automatic reporting, and the ability to move data instead of experts (to the flightline.) Data archiving and analysis can feed into advanced prognostics and other aspects of a condition-based maintenance (CBM) concept. Today we capture, analyze, share, report, and archive digital inspection information. Digitization is increasing productivity significantly.”

Reporting, coordinating, and evaluating can now happen faster thanks to digital collaboration. Menu-directed inspection allows for automatic reporting; tagged images are automatically filed into the report. Images that appear out of limits are tagged with the joystick and can be automatically sent to an expert for evaluation with a push of a button. In the past, the image would have to have been downloaded and emailed.

“We’ve seen up to a 70 percent reduction in reporting time and 50 percent faster return of an asset in other industries. We hope to bring similar productivity advances to airlines using MDI and video borescopy,” says Murner. “While we are still in the early stages of understanding the complete benefits of these inspection enhancements, we’re estimating that total savings could add up to about $19,000 per inspector.”

In addition to MDI employed on the borescope or other diagnostic equipment, software programs are turning information into intelligence for the technicians, engineers, and operations managers, allowing them to simply capture, analyze, share, report, and archive digital inspection information. Digitization is allowing more consistency in reporting with faster turnaround, expert review and analysis, and data storage and trending.

While digital collaboration is new, it is widely accepted and gaining momentum in industries like oil and gas. Aviation technicians are also beginning to understand the potential benefits within their industry.

“Aviation tends to be more conservative and for good reason,” says Murner. “Human safety is critical, but cost effectiveness and productivity are also very important. Finding ways to make the inspection and maintenance process go faster and cleaner while ensuring accuracy and quality is a big deal. Digitization will continue to advance, bringing even greater benefits to the aviation industry.”