Bench Talk

The tragedy that befell Southwest Flight 1380 in April 2018 is thankfully a rare event in modern air travel. But one tragedy is still one too many. Complete system safety may be a goal that is always just out of reach. However, the desire to attain such perfection is what drives engineers, scientists, and technicians in many fields of technical pursuit. No doubt, modern aircraft are wondrous engineering feats. But future technologies, now still in development, might help bring us one step closer to even safer, more reliable aircraft and other systems where human life hangs in the balance.

The National Transportation Safety Board (NTSB) is still investigating what exactly happened that resulted in one death aboard the Dallas-bound flight. The accident marks the first fatality on a U.S. flight in almost nine years. As of the time of this writing, investigators believe that a fan blade from one the aircraft’s CMF56-7B engines sheared off while at an altitude of around 9,800m and punctured the pressurized cabin. Investigations indicate that the blade sheared off possibly due to fatigue that metal alloys experience during flight. Heavy loads and cyclical temperature extremes can induce fatigue that all aircraft experience.

Today, airlines spend a lot of time and money on maintaining aircraft—including the engines and fan blades, which undergo routine ultrasonic imaging to look for microfractures after a set number of takeoffs and landings. Still, there could be thousands of flights between inspections, given the amount of effort required to do thorough strip downs, inspections, and repairs. These are human-in-the-loop intensive operations requiring judgment calls, countless external tools, and various types of diagnostic equipment. But what about tomorrow’s aircraft?

Digital twins (DTs) are a promising, new technological concept that might be able to help engineers and technicians understand the material conditions of an aircraft and its subsystems more than ever before. The installation of new generations of infrared and ultrasonic sensors are in the works that can detect microfractures while withstanding harsh the conditions within an engine. Leveraging capabilities and concepts like those underpinning the burgeoning Internet of Things (IoT), onboard sensors will deliver unparalleled data points to their DT via the conductive digital thread, without the need for manual human intervention.

The examples of how DTs could hone transportation safety are potentially limitless. For example, combining the flood of new data points with immense processing horsepower, DTs could:

• Reduce the time it takes to perform teardown inspections by removing the relatively slow human from all but the most critical aspects of diagnosing machinery.
• Allow more time for technicians to spend on actual problems instead of burning through a checklist to check for every possible failure mode. Reducing inspection times is good for business, and if it results in even safer aircraft, then it’s a win-win for everyone.
• Enable prognoses not only based on data from the system under inspection but also from the collective data sets of all aircraft in the fleet. Being able to compare data sets, looking for common anomalies or unique outliers in the data, and doing so at the speed of modern computing could offer further benefits for more proactive system safety.
• Enable predictive “what-if” analyses on everything from swapping out different components for like components to seeing how altering a maintenance schedule affects material conditions. The simulations will run on the DT as it undergoes continual fine-tuning by actual data from live systems from real-world conditions. That is huge for better prognoses.
• Prioritize inspections by cross-referencing system data, such as maintenance history, installed components inventory, ambient operating environments, and onboard diagnostics from across the active fleet.

DTs enable engineers and technicians to make better, more informed decisions by quickly pulling data from entire system fleets and looking for trends in ways that have, thus far, been impossible to see. Engineers and technicians can play out what-if scenarios millions of times, without any threat to real systems or human life, in hyper-accurate simulations that real-world data can reinforce. Leveraging artificial intelligence (AI) to comb through raw data quickly will translate into improved safety by eliminating human errors in mining the minutiae of data. Then, humans can instead turn their focus to higher-level analysis and decision-making roles.

Technology may never be able to eliminate the risks involved in transportation or other activities, but that shouldn’t stop us from making it the goal. By building on past experiences and leveraging new technologies, we might get lucky enough to prevent one tragedy. And one tragedy eliminated would be enough. For more information, check out Mouser’s Methods eZine on Digital Twinning.