7 Mistakes that Derail Aircraft Certification and How to Avoid Them

Justin McKennon has participated in hundreds of aircraft certification campaigns. Now, as Chief Technology Officer at Electro Magnetic Applications, Inc. (EMA) and an FAA Designated Engineering Representative (DER), he is sharing the most common mistakes he sees during the certification process and how to avoid them.

One underlying theme runs through these mistakes: when decisions are made, how they are made, and what they are based on. Poor decisions lead to delays and inflated budgets, and they push engineering teams into reactive modes where every choice becomes harder and more expensive.

The good news is that teams can avoid these mistakes by approaching certification a different way from the start.

“The most important part of any certification program, bar none, is the ability to tie all the decision making that you are doing,” McKennon said.

Here are the top seven mistakes McKennon sees during a certification campaign.

Mistake 1: Treating Certification as the End of the Program

One of the most common, and costly, mistakes is treating certification as something that happens after the design is mature. McKennon explains that teams often justify postponing certification discussions because the aircraft is still evolving, but that delay creates major problems later.

“An aircraft that can fly but is not certifiable is a very expensive paperweight,” he says.

The right way: Certification should drive decision-making from day one. Addressing it early improves how teams define requirements, select systems, and implement protections. Certification is not where the program ends, it’s where it begins.

Mistake 2: Skipping Aircraft-Level Hazard Thinking

Many programs dive straight into system- or equipment-level decisions without clearly defining aircraft-level hazards. This approach misses the core objective of certification: demonstrating that conditions capable of crashing the aircraft will not occur during its intended operation.

For electromagnetic environmental effects (E3), figure 1, these hazards must then be filtered further. The question becomes: Could any of these failure conditions be caused by indirect effects of lightning? That filtering defines which systems, wiring, and electronic functions matter most.

Fig. 1. Overview of electromagnetic environmental effects (E3) hazards encountered by aircraft.

The right way: Start at the aircraft level. Identify unacceptable failure conditions first. Use those hazards to bound which systems and environments deserve attention. Everything downstream becomes more focused, defensible, and efficient.

Mistake 3: Delaying Aircraft-Level Characterization

Another frequent mistake is delaying aircraft-level electromagnetic characterization until the design feels “final.” In reality, designs never stop changing and waiting for perfection leads to decisions made without context.

“I think that’s a huge mistake because ultimately that aircraft data is the burden that you will have to deal with when you get out of the design stage,” McKennon says.

Aircraft-level characterization establishes the external and internal environments that form the basis for all qualification, test, and certification activity. Without this data, requirements are often guesses, and guesses introduce unbounded risk.

The right way: Begin aircraft-level characterization early, even without incomplete information. Conservative assumptions, first-order analysis, and bounding conditions provide far more value than waiting for a perfect model that will never exist.

Mistake 4: Letting Assumptions Accumulate Without Recognition

Every time a requirement, protection, or mitigation is not explicitly tied back to aircraft-level data, an assumption is introduced. In isolation, assumptions may seem harmless. Together, they become dangerous.

This happens most often when different parts of the aircraft mature at different rates. A reused vendor unit might move quickly, while other systems lag behind. Without aircraft-level anchors, design decisions are made on instinct rather than evidence.

The right way: Every major decision should tie back to aircraft-level hazards and environments. Assumptions should be explicit, conservative, and documented. If risk is being added, it should be recognized not hidden.

Mistake 5: Over-Reliance on Integrated System Testing

Integrated system testing is one of the biggest time and cost drivers in any aircraft program. Yet it is often underestimated.

These campaigns require fully functional hardware, complex lab setups, limited facility availability, and significant coordination. They take months, not weeks, and anomalies are inevitable. Too many programs assume success and plan accordingly.

Fig. 2. EMA staff completing testing configuration for high-intensity radiated fields.

“I always advise new companies when they’re trying to spin up a new aircraft or start a new process, it’s about $1 billion to do that,” McKennon stresses. “There’s a lot of paperwork that goes into it, and they’re always started too late and without an understanding of what they entail. And it has kicked a lot of people’s backs over the years.”

The right way: Integrated system testing should be a demonstration, not a discovery exercise. The goal is to prove behavior you already understand, not to figure out what might happen. Analysis and early testing should burn down uncertainty so system-level tests can be executed once and executed well.

Mistake 6: Running Tests Without a Clear Purpose

Fig. 3. Physical aircraft testing setup. Courtesy of Embraer.

Tests should never be run “just because” or simply to check a compliance box. Every test must exist to answer a question:

• Which hazard does it address?
• What risk does it reduce?
• How will the data be used later?

Too often, test results become standalone lab reports with no lasting impact.

“Certification is a process, it’s a story,” McKennon stresses. “You can’t just present data and then not have the process to back it up. In my work with the FAA, I know this because we see it all the time. The FAA needs to trust your decision making and your process as much as it does your data.”

The right way: Treat test data as a long-term asset. Plan how it will be aggregated, reused, and referenced. Capture why a test was run, not just what happened.

Mistake 7: Starting Analysis Too Late

In many programs, analysis shows up only after schedules start slipping. At that point, it becomes a panic-driven exercise used to explain problems rather than prevent them.

This is a missed opportunity. Early analysis does not require high fidelity. It does not need perfect geometry or exact layouts. It needs physics, bunding logic, and conservative assumptions.

Fig. 4. Example of an aircraft simulation model.

The right way: Use analysis early as a decision-support tool. As the program matures, increase fidelity where it adds value. Early analysis informs requirements and risk posture. Later analysis supports validation and refinement.

Early analysis is the perfect time to bring in simulation.

“Modeling gives us an opportunity for similarity assessments and design iterations for go backs without having to build a new article. I could not champion that any harder,” McKennon points out.

Fig. 5. Aircraft simulation as seen in Ansys EMC Plus.

Clearing Certification Hurdles  

Today’s aerospace industry is building clean-sheet aircraft: advanced air mobility platforms, new military aircraft, and novel architectures. Many engineering teams have never navigated full certification processes before. They cannot lean on service history because it does not exist.

EMA brings FAA-level perspective that helps teams make defensible decisions early, before assumptions turn into expensive rework. By combining engineering expertise, analysis, and simulation, EMA’s approach helps programs reduce risk, streamline testing, and shorten certification timelines. The result is a clearer path to approval that saves both time and money.

If your team is preparing for certification, or trying to get back on track, reach out to EMA now to start the conversation and avoid costly missteps before they happen.

Hear more from McKennon in the Ansys Part of Synopsys webinar “Certification by Analysis: Navigating Lightning, HIRF, and EMC Certification with Confidence.” Watch on-demand by clicking here.