Simulation technologies, such as computer-aided design (CAD) or finite element analysis (FEA), allow aerospace engineers to visualize complex part geometries, understand how parts respond to applied loads (structural analysis), and optimize tooling resources. Digital twins allow machine- asset monitoring and supply chain management. These technologies reduce costs by pulling critical product decisions further upstream where processes and simulations are less expensive than physical prototyping and testing physical prototyping and testing.

Similar benefits extend to testing, where technology increases the efficiency of quality assurance processes. Real-time data acquisition and processing, digital repositories for customer specifications, and collaborative workflow tools accelerate product rollouts.

Virtual testing – using computational modeling and simulation to improve designs and material properties – exposes a design to real-world loading and material properties to identify undesirable results before they happen. Virtual testing also optimizes maintenance, improving sustainment costs and reducing warranty risk – results American Airlines discovered firsthand.

Case study

In 2007, the Federal Aviation Administration (FAA) mandated American Airlines to cold start auxiliary power units (APUs) for each of its Boeing 777 aircraft once per quarter. Increased testing led to three to four APU removals each year, which were expensive, left aircraft out of service, and produced an unpleasant cabin odor upon failure. Bearing failures were to blame, but American Airlines couldn’t pinpoint the source of the problem: Was it the material, design, lubricant, or operating protocol?

To find the answer, materials engineering software company Vextec performed virtual tests analyzing a new APU bearing as well as a bearing broken by operating. The team also evaluated general operating condition notes provided by American Airlines. Vextec’s simulations studied sensitivities related to normal versus cold start, load and design, and lubrication. The studies showed the bearing design was appropriate, but the way the cold starts were performed caused the failures – and the lubrication needed to be changed.

After receiving FAA approval of this solution, American Airlines introduced new lubricant and cold start protocols in August 2011. Since then, the carrier has experienced no APU failures and saved up to $4 million annually. That improvement came while avoiding exorbitant physical testing costs and time commitments for bearings. Plus, American Airlines didn’t have to redesign the bearing, which simulation testing showed would lead to more failures.

Industry 4.0 and AM

Virtual testing is one of many technologies transforming aerospace manufacturing as part of Industry 4.0. Additive manufacturing (AM) plays a bigger role in that transformation by presenting a fundamentally different way to build aircraft.

As AM becomes more capable in production of flight-critical metallic parts, it will impact original equipment manufacturers (OEMs) and maintenance, repair, and overhaul (MRO) operators. Better control of production volume and just-in-time manufacturing should lower costs for OEMs. Producing replacement legacy parts that would otherwise be difficult to source will be a key revenue generator for MRO.

Closely tied to making AM able to produce critical parts is effectively certifying AM-built parts for use. Since AM processes have shown to be more variable than conventional processes such as casting and forging, typical quality assurance/quality control sampling techniques (for example, testing only a small number of produced parts) are difficult to implement. Virtual testing using a computational simulation of product performance can increase confidence in AM for critical uses without the need to test each AM-built part – similar to what American Airlines did with its APU bearing.

Implementing technology

Steps to technology adoption include:

Empower designers. Technologies that provide designers more actionable intelligence earlier in the product development life cycle eliminates dead ends in design and manufacturing. This can significantly reduce the time necessary to develop new components while cutting overall program costs.

Optimize product lifecycle management (PLM). PLM extends from early design phases through user performance. Technologies that can address multiple areas of PLM at once – such as simulation software – optimize PLM with the largest repository of data possible to create a feedback loop throughout the life cycle.

Leverage third parties. Software subscriptions often include technical and product support, adding value when integrating the technology into an established PLM workflow. Subscriptions are also more affordable and flexible than purchasing software outright.

Think holistically. AM, known mostly for rapid prototyping, can handle production in some instances. Explore how new technologies fit holistically into the PLM to identify areas it can (or can’t) apply.

Respect certifications. Existing parts made with new production methods can be hard to certify. When choosing solutions, set up ways to certify that they meet quality standards – especially when certifications may not yet exist.

Aerospace manufacturers must see technology for what it truly is: the future of the industry. For all the advancements and improvements made in recent decades, they pale in comparison to what will be possible, and, in many cases, what’s already possible for those who embrace the opportunities.

Vextec Corp.

About the author: Dr. Robert Tryon is the co-founder and CTO of Vextec, a software and engineering services company specializing in predictive analytics, prognostics, and life extension for automotive, aerospace, industrial, and medical device products. He can be reached at or 615.372.0299.