In aviation, safety is — and must always be — the highest priority. At the heart of this is the principle of airworthiness: ensuring aircraft are safe to operate. Regulations, certifications, inspections, and procedures all serve this single aim.
But in some cases, well-intentioned adherence to regulation can become so rigid, so literal in interpretation, that aircraft may end up grounded not for safety reasons, but because of procedural inflexibility.
This phenomenon — what we might call groundworthiness — occurs when compliance becomes so narrowly defined that aircraft remain serviceable on paper but unusable in practice.
This is rarely due to negligence or unwillingness, but more often the result of differing interpretations — particularly around Acceptable Means of Compliance (AMCs) and Guidance Material (GM).
These are designed to assist with meeting regulatory requirements, but across the aircraft maintenance ecosystem — including engineers, quality staff, and operational leaders — they are sometimes mistaken for mandatory rules. When this occurs, the unintended outcome can be significant inefficiencies, grounded aircraft, and growing frustration.
This article explores how such misinterpretations can arise and how organisations can navigate compliance in a more balanced, risk-informed manner — without compromising safety.
What are Acceptable Means of Compliance and Guidance Material?
AMCs are methods that illustrate how regulations can be met, and Guidance Material (GMs) provides further support. While these tools are designed to assist, they are sometimes misinterpreted as mandatory rules.
Understanding the true purpose of airworthiness regulation
Airworthiness refers not only to the physical condition of an aircraft, but also to its certification, maintenance records, and conformity with regulatory standards. Authorities such as the European Union Aviation Safety Agency (EASA) and the Federal Aviation Administration (FAA) issue regulations to ensure consistency and safety across all phases of an aircraft's lifecycle.
Importantly, modern regulatory frameworks are designed to be performance-based and risk-informed. Instead of dictating a single path, they offer flexibility in how safety outcomes are achieved. That is where AMCs and GMs come in — as tools to guide and support compliance, not define it in absolute terms.
As EASA puts it:
“The AMCs issued by EASA are not of a legislative nature. They cannot create additional obligations on the regulated persons, who may decide to show compliance with the applicable requirements using other means.”
(EASA, Easy Access Rules for Continuing Airworthiness)
Similarly, the FAA states:
“Guidance is not binding; it represents one way, but not the only way, of complying with the rules.”
(FAA Order 8900.1, Vol. 3, Ch. 1)
Almost all FAA Advisory Circulars (ACs) include a disclaimer stating that they present one acceptable means, but not the only means of compliance.
For clarification an FAA AC is the equivalent of EASA AMC’s
Acceptable Means of Compliance: More than one way to fly
An AMC provides one example of how a regulation may be met. It is not the only option. EASA explicitly allows for Alternative Means of Compliance (AltMoC), as long as the safety objective is met and the competent authority agrees.
However, in practice, many professionals interpret AMCs conservatively — not due to lack of competence, but from a desire to avoid audit findings, regulatory pushback, or ambiguity. This tendency exists across the board, from engineering and quality teams to maintenance crews and technical managers.
This is why, when you move between different companies in the aviation industry, you often find that procedures can vary. Take, for instance, the practice of On-the-Job Training (OJT). Some companies allow certain tasks to be carried out verbally, relying on experienced technicians to explain the process rather than demonstrating it physically.
Other organisations, however, may insist on requiring each task to be physically performed on the aircraft. EASA regulations don’t explicitly mandate that every task must be physically demonstrated, nor do they outright prohibit the use of verbal instruction.
The flexibility in this approach is beneficial, particularly for OJT tasks that are infrequent.
For example, one could argue that a verbal demonstration might be more effective than no demonstration at all.
The flexibility built into the regulations allows for different interpretations and implementations depending on the company’s approach and operational needs. This variability can sometimes lead to confusion or inconsistency, but it also highlights the importance of understanding the spirit of the regulations rather than adhering to a rigid, one-size-fits-all mindset.
In the past, ambiguity in regulations was often viewed as an annoyance — a grey area that created frustration and uncertainty. Many saw it as a source of confusion, something that slowed progress and made compliance feel like navigating a maze.
However, in reality, this ambiguity is one of aviation’s most valuable assets. It allows for flexibility — a crucial element in an industry that is constantly evolving. Ambiguity lets companies adapt to new technologies, implement innovative processes, and tailor their approaches to meet unique operational needs, all while still maintaining safety.
Without this flexibility, aviation would become bogged down in rigid, outdated rules that stifle progress and fail to accommodate the dynamic nature of the industry. Embracing the space between the lines enables professionals to apply risk-based decision-making, adjust practices as needed, and ultimately improve both safety and efficiency.
What once seemed like a source of frustration can, in fact, be a tool that fosters growth, innovation, and better outcomes in the long run.
Compliance culture: A shared responsibility
Within maintenance organisations, quality assurance functions are crucial. Their role is to ensure regulatory adherence, uphold standards, and protect the certificate of approval. Yet the way this role is carried out can have a profound impact on operational performance and safety culture.
When compliance is seen as a collaborative, enabling function, quality teams become trusted advisors. But when compliance becomes overly risk-averse or disconnected from practical operations, organisations may drift into a form of paralysis — where doing nothing feels safer than doing something that might be questioned.
This dynamic is rarely the result of bad intent. It often stems from:
- Fear of findings or regulatory scrutiny.
- Insufficient clarity or confidence in interpreting AMCs and GMs.
- A lack of tools or processes for handling justified deviations.
- Organisational cultures that prioritise the absence of error over the presence of safety.
Just culture and safety management: Foundations for balanced compliance
One of the pillars of modern aviation safety is the concept of Just Culture — an environment in which people are not punished for honest mistakes or well-intentioned actions, but are instead supported to speak up, question norms, and make informed decisions.
Just Culture is deeply embedded in the Safety Management System (SMS) framework mandated by both EASA and the FAA. Under SMS, organisations are expected not only to follow procedures but to understand risk, learn from experience, and adapt intelligently.
“A Just Culture is one where front-line operators and others are not punished for actions, omissions, or decisions commensurate with their experience and training, but where gross negligence, wilful violations, and destructive acts are not tolerated.”
(ICAO Doc 9859)
Applying Just Culture to compliance means recognising that sometimes, the safest decision may require stepping outside the AMC — with proper rationale, documentation, and oversight. It is about managing risk, not eliminating it at all costs.
A case study in flexible compliance
Case study: The delayed decal
An operator in Europe was preparing an aircraft for a seasonal lease return. As part of the workpack, a livery decal needed to be removed and replaced. The OEM-specified removal solvent was temporarily unavailable, but the engineering team proposed an approved equivalent — which had equivalent performance characteristics. A materials compatibility report was included, and the alternative posed no increase in operational risk.
Despite engineering’s support, the task stalled for three weeks. The quality assurance team required formal clarification from the OEM, which was slow to arrive. The aircraft delivery was delayed, the operator incurred penalties, and team morale suffered.
A post-incident review identified no safety breaches but concluded that the AMC had been interpreted too narrowly. An internal AltMoC procedure was developed as a result, allowing faster, structured responses to similar situations in future.
This is a typical example of how well-intended caution can lead to avoidable outcomes — and how processes, not people, are often the root cause.
Enabling a healthier compliance ecosystem
To shift from rigid compliance to smart compliance, organisations should embed several principles into their safety and quality culture:
1. Education and training
- Train staff in the purpose and interpretation of AMCs and GMs.
- Emphasise the difference between rules and guidance.
- Share examples of successful AltMoCs and regulatory engagement.
2. Cross-functional collaboration
- Involve quality teams early in engineering decisions.
- Foster a team-based approach to compliance problem-solving.
- Avoid siloed decision-making that delays safe solutions.
3. Promote a Just Culture
- Encourage reporting, questioning, and challenge.
- Recognise that deviations — if well managed — can be legitimate and even beneficial.
- Embed SMS principles into everyday maintenance practice.
4. Use alternative means of compliance
- Create transparent AltMoC processes with clear responsibilities.
- Ensure proposals are well documented and justifiable.
- Track and analyse outcomes to build confidence over time.
5. Engage with regulators
- Build open, constructive relationships with competent authorities.
- Share lessons learned and seek guidance early where needed.
- Demonstrate that flexibility is being used to enhance — not weaken — safety.
Conclusion
Airworthiness is about outcomes, not just process. Aircraft must be safe — but they must also fly. When AMCs and GMs are misunderstood as rigid mandates, the result can be a kind of procedural overreach that grounds aircraft unnecessarily.
This issue is not unique to any one department, job role, or organisation. It is a shared industry challenge — and one that can be addressed through education, communication, and culture. By rebalancing how we interpret and apply compliance tools, we can support both safety and operational resilience.
Quality assurance should remain a vital check in the system — but also a partner in problem-solving. When empowered with the right knowledge and culture, quality teams can help unlock smarter ways to maintain aircraft, without compromising safety.
Because an aircraft that never leaves the hangar may be compliant — but it is not airworthy. It is groundworthy. And the industry’s true mission is not just to meet the rules, but to keep aircraft flying — safely, sensibly, and sustainably.