Why Critical Thinking Matters in Aviation Maintenance Training?

What Every Maintenance Technician Must Understand About Manuals

Critical thinking in aviation maintenance begins where the manual ends. Manuals are the backbone of the profession, they ensure a controlled, standardized, and auditable process. In the US, for instance, the process is defined by the need for the maintainer to apply the methods, techniques, and practices prescribed in the current manufacturer’s maintenance manual or Instructions for Continued Airworthiness, or other methods acceptable to the regulator. ¹

Critical thinking in aviation maintenance training – Cockpit familiarization session with Florian Schaller

However, as Florian Schaller, an Academy Aviation Group instructor, explained, “manuals are not the same as judgment.” As he explained, “Real work is done in an environment of interruption, tiredness, commercial pressure, poor information, and an aircraft that doesn’t match a ‘perfect scenario’ depicted in a book.” This is precisely why contemporary human factors advice is that “aviation maintenance is an error-prone process, even for experienced and well-trained maintenance workers.” This is also why safety occurrences need to be used as a learning experience for the organization, so that the same safety failures are not repeated again. ²

During a recent discussion with Florian Schaller, an experienced instructor at Academy Aviation Group, he shared an important lesson he learned from experience that students don’t always find in manuals.

Manuals are important because they provide structured knowledge and clear instructions. However, experience teaches lessons that cannot always be found in written guides. In real life, situations are rarely perfect or predictable. Plans change, problems arise unexpectedly, time pressure, shifts or late hours and people react in different ways. Through experience, students learn how to adapt, make decisions under pressure, and handle uncertainty.

One important lesson is understanding the big picture. It is not enough to simply follow information; technicians must think critically about what they have read. They need to ask whether a method can work like described the situation and what assumptions it depends on. Seeing the broader context helps prevent mistakes and misapplication of knowledge. For example, how does the aircraft need to be configured to activate the system – Aircraft on Jacks, Electrical or hydraulic power required or even basic things as the logic in the system. At the same time, basic common sense is key. Technicians should question whether what they read is even plausible.

Does it logically make sense? Does it match real-world observations? Experience strengthens this judgment and builds confidence. In the end, manuals provide theory, but experience provides wisdom. True understanding comes from combining knowledge, critical thinking, and common sense. We see a lot of false or incomplete information in the manuals and guidelines and common sense helps identify these errors and complete the task correctly.

How does human information processing explain “manuals vs experience” in the hangar?

“Why do skilled technicians still make mistakes, even with manuals?” CAP 715 (An Introduction to Aircraft Maintenance Engineering Human Factors for JAR 66) answers that by stepping back from procedures and looking at the human brain. Describes information processing as receiving information through the senses, analysing it, and making it meaningful, and it provides a functional model that runs from sensory input to decisions, actions and feedback. 

CAP 715 states that short-term (working) memory can store only a relatively small amount of information, about 5 to 9 items, and typically for 10 to 20 seconds; it also describes sensory memory as a brief buffer. 

This is one reason Florian’s “common sense” point matters: if a procedure step depends on remembering an assumption you read minutes ago (power state, jacks, interlocks), you are relying on a fragile system.

CAP 715 therefore recommends using manuals and temporary aides‑mémoire rather than relying on memory, even for seemingly simple details like torque settings, because interruption and interference can cause confusion or forgetting between reading the manual and doing the task. 

It also warns that maintaining a personal notebook of technical data can be dangerous because information may become out of date, an important reminder that “experience” must be paired with currency control. 

Why do experienced instructors give students a measurable advantage?

Students often ask: “Should I choose an instructor with more real-world experience, or someone who teaches well?” The evidence suggests the best answer is: choose instructors who do both, but experience is hard to replace in certain learning objectives.

Florian said that:

One of the important maintenance issues in the real world, which students do not learn from manuals, is that many aircraft malfunctions occur during flight, but most troubleshooting and testing are done on the ground. Therefore, a major factor is absent during troubleshooting, which is actually present during flight, i.e., temperature, pressure, vibrations, airflow, and speed. As a result, it is possible that a system may pass all tests on the ground, but it can have the same problem during flight. In such cases, it is possible that the maintenance personnel may have actually followed all the procedures described in the manuals and performed all the tests, but the problem is still there. It is here that experience and critical thinking play an important role. These issues are not always described in the manuals, and it is here that experience and common sense are required to understand the difference between testing on the ground and testing during flight

The structure for training and licensing demonstrates that experience is a necessity rather than a choice. The FAA requires that a practical experience component exist for certification as a mechanic, illustrating that competence is a product of both knowledge and practical work. FAA maintenance schools also require that their instructors are qualified individuals with actual credentials. EASA in Europe defines maintenance experience as actual work on real aircraft, often with a Part-147 training component in a type of apprentice-style approach. EASA also indicates that instructors should be trained in areas such as teaching methods and human factors, illustrating that competence in training involves actual experience, teaching skills, and understanding human factors.

Want to learn maintenance judgment, not just procedures? Train with Academy Aviation Group and learn how experienced instructors teach configuration logic, documentation discipline, and human factors. “Speak to Academy Aviation Group about maintenance training designed around real human performance limits, attention, interruption, and memory, and the countermeasures used in industry.

Short FAQ

1. What are manuals, and why are they not sufficient in aviation maintenance?
   Manuals are a requirement, and they are important, but procedures can be incorrectly applied due to incorrect assumptions, and some manuals can be inadequate, confusing, or impractical, so judgment and reporting are important.
2. What does ‘critical thinking’ mean for an AMT in plain language?
   Critical thinking for an AMT means checking assumptions, verifying assumptions, recognizing when something does not make sense, and using manuals, as well as evidence (indications, symptoms, logic) to make a decision.
3. Can even experienced AMTs make mistakes?
   Yes, in fact, safety information from a reputable source reports on misrigging incidents where highly experienced mechanics made critical mistakes.
4. What can even highly experienced instructors contribute to help a student learn faster?
   They can contribute significantly by making judgment explicit through modeling, coaching, scaffolding, and fading (cognitive apprenticeship) and by helping a student use a process of experience, reflection, concepts, and re-practice (experiential learning)

Referencing

1. FAA performance rule requiring use of current manufacturer maintenance methods (14 CFR § 43.13). 
2. CAA CAP 715 (human performance, information processing model, attention/perception, memory limits, and the AAIB B737 case excerpts). 
3. CAA CAP 718 (maintenance pressures and “windows of opportunity” for error; learning from occurrences). 
4. FAA Human Factors Guide for Aviation Maintenance and Inspection (procedure error contribution; “wrong” procedures; verification vs validation; realistic testing). 
5. EASA AMC/GM to Part‑145 (process for inaccurate/ambiguous maintenance data; notifying author; internal reporting). 
6. EASA AMC/GM to Part‑147 (documentation access and updates; instructor training methods). 
7. Cognitive apprenticeship (modeling → coaching → scaffolding → fading; making expert processes visible). 

Written by Stamatina Kiriazou | Contributed by Florian Schaller