Aircraft Maintenance: Everything That Happens to Keep an Airplane Flying

Season 2 Episode 19 | October 14, 2026

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Behind every flight are hundreds of technicians, engineers, inspectors, and specialists working to ensure that an aircraft can operate safely. In this episode of Altitude, we speak with Jorge L. Jácome about one of the most important - and least visible to passengers - areas of aviation: aircraft maintenance.

Jorge L. Jácome has nearly four decades of experience in the aviation industry. An aeronautical engineer from Mexico’s National Polytechnic Institute (IPN), he began his career at Mexicana de Aviación in 1987 and later held leadership roles in Engineering, Maintenance, Fleet Planning, and Mexicana’s MRO operation. Today, he leads a technical organization of more than 2,500 engineers and technicians.

His career provides the starting point for an apparently simple question: what has to happen for an airplane to take off safely, day after day?

Maintenance begins long before a failure appears

Unlike a car, whose maintenance we often associate with a certain mileage or a trip to the shop every few months, aviation relies on maintenance programs defined by aircraft manufacturers and then adapted to each airline’s operation.

In broad terms, there are two major categories: line maintenance and heavy maintenance.

Line maintenance happens practically every day. During a stop between flights - what the industry commonly calls a transit - technicians check fluid levels, wheels, visible damage, and any issue reported by the flight crew during the previous leg.

Heavy maintenance, by contrast, involves much deeper inspections and work. Scheduling depends on factors such as flight hours, cycles - takeoffs and landings - and the age of the aircraft. Depending on the model and how it is operated, some of these major checks may be scheduled every two or three years.

What happens when an airplane arrives from another flight?

When an aircraft lands and prepares for another segment, the technician first reviews the information provided by the flight crew and the maintenance logbook.

If there is a reported issue, a troubleshooting process begins. Some systems can run self-tests from the aircraft itself; in other cases, technicians must physically inspect components, fluid levels, leaks, or other systems.

So while passengers are deplaning, the cabin is being cleaned, bags are being loaded, and the next flight is being prepared, a technical team is also verifying that the aircraft is in the proper condition to continue operating.

An airplane can fly with an inoperative component and still be safe

One of the concepts that creates the most questions among passengers is the MEL - the Minimum Equipment List.

Aircraft are designed with redundant systems. This means that, under clearly defined and documented conditions, certain pieces of equipment may be temporarily inoperative without compromising the safety of the flight.

The MEL specifies exactly which items may be deferred, for how long, and under what conditions.

That does not mean ignoring a fault. It means applying a previously approved procedure that allows the aircraft to keep operating until it reaches a base with the personnel, tools, and parts required to complete the repair.

An organization far larger than a group of mechanics

Behind the maintenance of an airline fleet is a massive organizational structure.

In addition to the technicians who work directly on aircraft, there are specialists in engines, components, landing gear, structures, and many other areas.

Engineering, quality control, planning, production, and maintenance control centers are also part of the operation.

In a fleet of more than 170 aircraft, not every airplane needs the same work at the same time. That is why systems are used to track when each task becomes due, which components are needed, and what human and material resources must be available to complete the work.

The operation works like a set of interlocking gears in which multiple specialties must remain continuously coordinated.

Quality control and quality assurance are not the same thing

The conversation also highlights an important distinction: quality control and quality assurance serve different functions.

Quality control is part of the technical operation. It includes specialized inspections, non-destructive testing, and examinations used to determine whether damage falls within approved limits.

Quality assurance functions more like an independent internal technical audit. Its job is to review processes, shops, documentation, maintenance services, and suppliers to verify that the organization is complying with applicable procedures and requirements.

These internal filters are complemented by audits from aviation authorities. The result is a system with multiple layers of oversight designed to identify deviations and support continuous improvement.

Who decides whether an airplane can take off?

The answer is straightforward: the technical personnel responsible for releasing the aircraft.

An airline may have passengers waiting, connections to protect, and an entire schedule to maintain, but if a condition prevents the aircraft from being considered airworthy, it does not depart.

When a fault appears before a flight, maintenance establishes an ETR - Estimated Time of Repair. Some situations may be resolved in 15 or 30 minutes; others may take hours if a component must be replaced or a part has to be sourced from another city or even another country.

As Jácome explains during the episode:

“We do not compromise on safety.”

Even when there is operational pressure or important passengers are on board, maintenance can determine that an aircraft must remain on the ground.

In Jácome’s words, it is better to go through an uncomfortable moment than to face a serious scare.

Aircraft reliability is measured every day

Maintenance organizations continuously track a range of indicators to understand how a fleet is performing.

One of them is maintenance dispatch reliability: the proportion of flights that can depart without a technical fault preventing the operation.

For modern aircraft, Jácome points to maintenance dispatch reliability levels of between 97% and 99%.

Teams also monitor delays, fleet availability, aircraft on ground - commonly known as AOGs - deferred maintenance items, and the functionality of cabin systems, including entertainment and connectivity.

Can a 25- or 30-year-old airplane still be safe?

The age of an aircraft, by itself, does not tell the whole story.

Manufacturers define design lives based on years, cycles, and flight hours. As long as an aircraft remains within those limits and receives the required inspections and maintenance, it can continue operating.

Over time, however, keeping it in service becomes progressively more expensive. The structure accumulates wear, engines lose efficiency, and some maintenance checks require more labor hours.

Eventually, there comes a point when maintaining a particular aircraft may be less efficient than replacing it with a newer one.

That is why fleet renewal does not happen overnight. It is a staged process that takes into account reliability, fuel consumption, maintenance cost, and the age of each aircraft.

From fixing failures to anticipating them: predictive maintenance

Technology is transforming this field in a profound way.

Modern aircraft transmit information about engines and other systems while they are still in flight. That information can be analyzed on the ground to detect deviations before the aircraft lands.

In some cases, the maintenance team already knows that a potential fault exists before the technician ever boards the aircraft.

The evolution has been significant: the industry moved from corrective maintenance, where something was repaired after it failed, to preventive maintenance based on scheduled inspections and cycles, and then to predictive maintenance, where data can help anticipate potential problems.

Artificial intelligence can accelerate this process even further by analyzing large volumes of information and identifying patterns that can improve component reliability.

Will artificial intelligence replace maintenance technicians?

Jácome does not believe so.

Aviation is a highly regulated industry, and every intervention requires documentation and responsible personnel who certify that the work was performed correctly.

Technology can help diagnose, analyze, and predict, but there are still decisions that require human involvement.

And as aviation continues to grow and more aircraft enter service, the need for specialized pilots, technicians, and engineers will grow as well.

An industry full of opportunities

For people looking to begin a career in aviation, today’s landscape is very different from the one Jácome encountered when he started.

Four decades ago, the options for studying aeronautical engineering in Mexico were far more limited. Today, there are dozens of educational institutions and a significant aerospace industry spread across several regions of the country.

Working in aviation also does not necessarily mean working for an airline. Mexico is home to manufacturers of aircraft, engines, components, and structures, as well as companies focused on aerospace design and maintenance.

The challenge, Jácome notes, is not only to develop technically capable professionals. It also involves managing human factors, integrating different generations, maintaining continuous training, and adapting to new technologies and new ways of working.

Everything passengers do not see when they board an airplane

For a passenger, a flight may begin at boarding and end at baggage claim.

For maintenance, the operation never stops.

Behind every aircraft is a combination of technicians, engineers, inspectors, control centers, manufacturers, suppliers, procedures, and oversight systems working around the clock.

Perhaps that is one of the central conclusions of this conversation: much of aviation safety happens far from the passenger’s view.

And precisely because we rarely see it, we are often unaware of the scale of the work required before an airplane can close its doors again, start its engines, and take off once more.

Listen to the full Altitude episode with Jorge L. Jácome for an inside look at how aircraft maintenance works, how the technical decisions that keep an operation safe are made, and where the profession is heading.