Perspectives: Why Failure Almost Always Begins Long Before Takeoff

Whenever an aviation accident makes headlines, public attention tends to focus on the final moments of the flight. The first question is almost always: Was there pilot error? In practice, however, aeronautical investigations follow a substantially different path. Rather than looking at only the last few minutes of the operation, investigators trace the aircraft’s history back weeks, months, and in some cases years, analyzing maintenance records, inspections, repairs, component replacements, and technical reports in search of evidence that may explain how a failure developed into a critical event.

This happens because aviation accidents are rarely the result of a single error or a sudden failure. In most cases, they stem from a combination of factors that accumulate over time and eventually breach successive layers of protection designed to ensure operational safety. In other words, most failures do not arise instantaneously. Fatigue cracks, corrosion, structural wear, and anomalies in safety-critical systems typically evolve slowly and silently. This is why maintenance and technical inspections are the primary barrier between an unsafe condition and a safe flight.

One of the greatest challenges in aeronautical maintenance is precisely identifying problems that have not yet shown visible signs. Components can sustain internal wear, hidden corrosion, or minor structural deformations that go undetected during a superficial assessment, yet may progress steadily if not identified in time.

In this context, nondestructive testing (NDT) plays a fundamental role in modern aviation. These techniques allow evaluation of material and structural integrity without damaging the aircraft, significantly expanding the ability to identify failures before they pose operational risks. Methods such as eddy current testing, liquid penetrant testing (PT), magnetic particle testing (MT), ultrasonic testing (UT), and borescope inspection can detect defects that are nearly invisible to the naked eye, increasing inspection reliability and reducing dependence on visual assessment.

Phased array ultrasonic testing (PAUT) can be used to detect internal discontinuities and verify structural integrity in critical areas where conventional visual inspections may not reveal hidden defects.

For example, during aircraft heavy maintenance inspections, ultrasonic testing (UT) is frequently used to evaluate structural components after corrosion removal. In one case, ultrasonic thickness mapping was performed to measure the remaining material thickness after blending out the corrosion—grinding the affected material to a smooth, faired contour—on the aircraft structure. The collected data enabled engineers and structural repair specialists to accurately assess the component’s condition and determine the most appropriate repair strategy.

Technology has greatly expanded prevention capabilities. Today, anomalies can be identified at very early stages, when they still pose no threat to operations, and that makes all the difference for the safety of the aircraft and its occupants.

Another essential element is what are known as heavy checks, or heavy maintenance inspections. Performed at scheduled intervals, these inspections involve extensive disassembly and in-depth evaluations of the aircraft, providing access to areas not normally examined during routine maintenance. These procedures require a high level of technical expertise, rigorous planning, and full adherence to OEM requirements and regulatory authority standards. Aviation safety does not depend solely on onboard technology or pilot skill—it is built daily inside the hangars.

Behind every aircraft that takes off, there is a team of mechanics, inspectors, engineers, and specialists working out of the spotlight. These are professionals responsible for interpreting data, following procedures, assessing risks, and making decisions that directly impact flight safety. Society tends to view aviation safety through the lens of what happens on the flight deck, but it begins long before that.

Well-trained teams are capable of identifying operational deviations, raising nonconformance flags, and acting preventively before small problems become significant risks. This is why, when discussing aviation safety, it is important to understand that it does not originate on the runway, nor does it begin when the engines are started. Aviation safety is the result of a continuous process of prevention and operational discipline.

What keeps aviation as one of the safest modes of transportation in the world is not the absence of failures, but the capacity to identify and correct them before they have the opportunity to manifest in flight. And that work begins long before takeoff.

About the Author

Glaysson Henrique Rocha Cruz is a production engineer specializing in aeronautical maintenance and aircraft structural integrity. He is an FAA A&P Quality Control Inspector and a Nondestructive Testing (NDT) inspector (ET, UT, MT, PT Level II), with experience in FAA/ANAC regulatory compliance.

Disclaimer: The views and opinions expressed in this article are those of the author and do not necessarily reflect the official position of ASNT. Articles in this series have not been peer-reviewed and are published for informational and professional development purposes only. Accuracy of technical content is the responsibility of the author.

About Perspectives

Perspectives is a digital series from Materials Evaluation featuring first-person insights from NDT practitioners, engineers, and specialists across the field. Articles in this series reflect the views of the author and have not been peer-reviewed. To submit a piece for consideration, contact the editorial team at jross@asnt.org.