The Art (and Science) of Keeping Flight Simulators Training-Ready

Like many disciplines, there is both an art and a science of performing maintenance on flight simulators. We generally like to think of it as more science than art (mainly because the types of people who do this kind of work are generally of an engineering mindset), but it can't be denied that there are some black arts at play when chasing down spurious faults in these systems. So what does it take to do a good job of maintaining these complex machines?

The First Step? Meticulous Maintenance Planning

Aviation training is a demanding business. Level D Full Flight Simulators (FFS) are the gold standard, and a non-negotiable requirement in modern pilot training; especially when it comes to commercial air travel. These rather large machines provide a highly realistic and immersive environment, allowing pilots to practice emergency response skills, run-through complex procedures, and maintain the highest levels of proficiency without taking up valuable time on a real aircraft that could be carrying fare-paying passengers.

Underneath the crew accessway

Given their brutal usage rates (most run on a 24/7 schedule), these critical pieces of training infrastructure must be pretty damn bullet proof to stand up to such significant demands. Their continuous use highlights the need for robust maintenance to keep them operational and, crucially, compliant with the regulations that govern their use. At the heart of effective training centre operation lies a requirement for well thought-out maintenance planning. The ability of an operator to effectively maintain it's simulators, directly relates to the fundamental aspects of flight simulation training: fidelity, overall safety, and economic viability.

So... is it the Same as Maintaining an Aircraft?

Maintaining a Full Flight Simulator (or an FTD for that matter) is, in many ways, not dissimilar to maintaining an aircraft of the same type - albeit with a modified skillset and approach required. In short, they're both complicated, and have some similarities, but you can't use the same systems and approach to maintain a simulator as you do an aircraft fleet.

Every component, from the motion and control-loading systems, to the high-resolution visual systems and the cockpit controls and instrumentation, must perform in accordance with it's qualification baseline - just one thing (of many) that separates the maintenance requirements of a simulator from an aircraft. Just as in an aircraft where each component contributes to the overall performance, each part of an FFS or FTD must function as designed to deliver the level of pilot training that modern operators require. Even the smallest discrepancy can disrupt the user's immersion and effectiveness of a training session, undermining the entire learning experience, and even potentially inducing negative training.

A modern I/O system

The demands of simulator maintenance are on par with maintaining an actual aircraft, but different in many ways. Both require specialised knowledge, precision tools, and a deep understanding of complex systems - plus the ability to read and interpret complex technical documentation before performing maintenance tasks. Neglecting the required maintenance is a recipe for long-term pain with your simulators. The initial savings made through avoiding these maintenance actions quickly vanish when faced with downtime, disrupted training schedules, irate pilots, negative customer feedback, and expensive repairs that could have been prevented or at the very least, delayed. For a flight simulator, such neglect translates directly into significant operational setbacks and financial risks (not to mention the potential for aviation safety risks through negative training).

Daily, Weekly, and Monthly Routines

To ensure the continuous operational readiness and high fidelity of FFSs and FTDs, a strict, multi-tiered maintenance schedule is followed - often specified by the Training Device Manufacturer (TDM), but also often extended by the device operator. This structured approach ensures that these sophisticated machines remain in optimal condition for pilot training.

Daily inspections are the first line of defence, covering critical system checks that ensure the simulator's immediate operational status. This includes verifying the functionality of lighting systems, checking sub-system calibrations for accuracy, and confirming the smooth operation of the motion systems, to name just a few. Engineers tend to these high-fidelity machines quite frequently to address any immediate concerns and maintain performance. Most training centres will run a schedule that includes a Before Flight (B/F) or Pre-flight Check every day on every device; checking all major sub-systems for correct functionality to ensure it's ready for training at the scheduled first session time. Most centres will also implement an After Flight (A/F) or Post-flight Check on each device, every day, to assess for any unreported faults and prepare for the following training day.

Greased bearings on a motion system

Weekly tasks move deeper into the device, involving more comprehensive system checks, cleaning, lubrications, sub-system resets, and calibrations. These routine adjustments prevent minor anomalies from escalating into more significant issues, ensuring continued accuracy and reliability. Cleaning is one of the most under-appreciated and overlooked tasks that provides a significant return on investment for the long-term health and performance of a simulator. Visual system alignments are often included as part of weekly scheduled maintenance.

Monthly maintenance involves a deeper system evaluations, which includes thorough diagnostic checks, heavier/dirtier system maintenance (e.g. motion and control loading), QTG validation testing, and sometimes essential firmware and software updates. These periodic checks updates are performed in order to prevent performance drift and to keep the simulator's behaviour aligned with the actual aircraft it replicates. Routine tasks at these intervals rarely include structural adjustments to the simulator's frame (but nonetheless it is sometimes required); but does often include lubrication of major moving parts (motion base, accessway, control loading elements, etc), and may include fine-tuning of the control loading, and motion systems to maintain their responsiveness and accuracy. Beyond the monthly schedule, long-term updates, such as major software overhauls or hardware replacements, are part of the ongoing sustainment process, scheduled to support changes required due to technological advancements, and obsolescence, and aircraft modifications and updates.

Predictive Maintenance

When it comes to getting the most from your training devices, predictive maintenance is becoming more and more relevant to simulator maintenance operations, with it's benefits in preventing unexpected failures. This approach moves past reacting to faults as they occur, and conducting scheduled maintenance in accordance with device documentation, and into the space of anticipating and mitigating issues before they occur and can disrupt training.

Inside the visual bowl, looking at the BP screen

Scheduled inspections to collect data-points, coupled with sophisticated real-time data analysis, empowers engineers to detect emerging issues early. This allows the maintenance team to address potential problems (such as minor wear on a hydraulic component or a slight dip in voltage on a battery system) before they escalate into critical failures and causing downtime. By intervening early, maintenance teams can significantly mitigate downtime risks, ensuring the simulator remains operational for scheduled training sessions. Good maintenance is fundamentally about preventing failures before they occur, not just responding to them as they occur. And with AI becoming a bigger part of every industry, simulator maintenance has significant opportunities to implement predictive maintenance strategies that utilise it to prevent an even larger number of failures than has been historically possible.

Balancing Maintenance with Operational Needs

One of the biggest and most persistent challenges in simulator maintenance is the science (and art) of balancing maintenance schedules with demanding client training needs. High quality planning is more than important; in fact it is an absolute necessity to minimise simulator downtime while ensuring the simulator remains fully functional and compliant.

An A320 FFS Cockpit

The reality for most training centres is that training slots for simulators are booked significant periods of time in advance (some months, some even years). This means that even a minor, unscheduled delay in maintenance can have a cascading effect, disrupting multiple pilot cohorts and leading to significant logistical challenges for both the training centre and its customers' flight operations. A well-planned maintenance strategy is therefore one of the most sensible things a centre manager can allocate resources towards. It supports the maximisation of training availability while simultaneously minimising disruptions. This intricate balancing act between logistics and engineering attention to details, and operational efficiency defines successful simulator maintenance management, ensuring that necessary maintenance is performed without compromising customer training schedules.

Data Logging and Monitoring

If your maintenance team isn't logging a substantial amount of data points, you're missing out on some very useful insights into your operations. The value of this data genuinely cannot be understated; it is an invaluable source to implement continuous improvement initiatives and increase your training centre's efficiency over time. Every simulator generates a massive amount of performance data during its operation. One job of the maintenance team is to track this stream of data, and find ways to use it to improve operations. Of course, these data sets are also highly useful for implementing predictive maintenance strategies - you just have to make sure you're measuring the right things. Continuous data-point tracking allows engineers to detect system and sub-system irregularities or deviations from expected values early on, often before they become apparent to the pilot or lead to a noticeable performance degradation.

A 3-channel visual system's projectors

Internally developed tools and other sophisticated software programs are used extensively in training centres to assist in every phase of maintenance. These tools aid in precise calibration of systems, streamline the part procurement process by identifying potential failures before they happen, and even facilitate audit preparation by maintaining meticulous records of all maintenance activities. Maintenance record keeping is an extremely important aspect of maintenance support - if there is ever an in-air safety incident, regulators may come knocking to review all of your records if training is suspected to be part of the cause. Such a comprehensive approach ensures smooth operations and optimises maintenance scheduling, transforming raw data into actionable insights. By using the vast amounts of performance data for predictive insights, maintenance teams can spot issues earlier and, consequently, face fewer disruptions to training.

Compliance and Fidelity

Maintaining strict compliance with regulations (as set by the relevant NAA), is crucial for ensuring that the simulator(s) remains an accurate, safe, and highly effective training tool. Regulatory compliance is formally managed through collaboration between operator and regulator; and requires a continuous process that directly impacts the validity and transferability of training received in the simulator.

Compliance is verified through two primary types of evaluations

Objective Evaluations

These involve the rigorous running of Qualification Test Guide (QTG) tests, specifically validation tests. These tests are designed to objectively verify that the simulator's aircraft systems, flight dynamics, and motion cues consistently meet strict certification standards and are typically run automatically through software with minimal user input. A remarkable number of QTG tests are performed on each simulator annually, showing the sheer volume of verification that is required. Engineers with specialised knowledge, experience and training are suitable to conduct these tests, utilising the simulator's master QTG as the recognised benchmark for compliant performance.

Subjective Assessments

The "cable waterfall" that connects the simulator to the computer room

Complementing objective tests, internal evaluations and flight tests are conducted by Subject Matter Experts (SMEs). These SMEs are typically experienced pilots and sometimes seasoned engineers who use their deep operational knowledge to conduct real-world scenario testing. Their subjective assessments, which are also defined within the QTG, help identify any potential discrepancies in simulator behaviour or fidelity that are not easily measured or captured by objective metrics, ensuring the training experience actually reflects actual flight conditions.

In addition to the simulator's core functionality, databases related to navigation, aircraft data, terrain, and visual landscapes must also be regularly updated. This is a crucial requirement per regulations, ensuring that the simulated environment remains current and accurate, reflecting any recent changes to things such as airfield markings or navigation aids. Falling short on these objective and subjective assessments can carry serious consequences, which can include temporary or even permanent suspension of training programs, directly impacting pilot qualification and operational readiness.

The Evolving Landscape of Flight Simulator Maintenance

The field of flight simulator maintenance is far from static; it is a dynamic discipline that continues to evolve with technological advancements. As the technology that is used to simulate aircraft evolves, so much the maintenance practices that are employed.

Advancements in AI look poised to impact maintenance management, offering the potential for real-time self-assessments that can predict wear and tear with high levels of accuracy. In the future, automated maintenance data collection, continuously monitoring performance, identifying subtle anomalies, and even predicting when a component might fail before it does is a genuine possibility. This AI-driven predictive maintenance capability could significantly enhance efficiency, potentially reducing the need for round-the-clock direct oversight and allowing maintenance teams to focus on strategic interventions.

Hydraulic motion base components

The prospect of simulators being able to "schedule its own maintenance", autonomously identifying optimal windows based on usage patterns and predictive analytics, is a vision that is still a way off - but there are several major vendors working on this very technology. It is, however, important to note that even with these technological advancements, human expertise will remain an important part of the mix. The analysis, problem-solving, and decision-making required for complex simulator maintenance will continue to rely on the skilled hands and experienced brains of dedicated professionals. Technology will augment, not replace, the art of keeping these critical training assets in peak training-ready condition.

Maintenance For Success

Maintaining a flight simulators is a multifaceted undertaking, it really is an art that blends cutting-edge engineering skills, smart technological foresight, and a significant degree of creative problem-solving. It is a continuous, complicated process that ensures the highly realistic and immersive training environment remains consistently available and accurate.

The ultimate goal of this maintenance is singular: to ensure that the next (and current) generation of pilots has access to the absolute best training equipment possible, preparing them for the complexities of real-world flight operations. By planning effectively today, we can secure the reliability and compliance of current training programs and enable the future innovations that will define the future of aviation safety. FAQs

1. How often do full flight simulators require maintenance? 

Full Flight Simulators (FFS) typically undergo a multi-tiered schedule: daily inspections (Pre-flight and Post-flight checks), weekly cleanings and calibrations, and monthly in-depth diagnostic checks. This ensures they can operate on a demanding 24/7 schedule without interruption.

2. What is the difference between maintaining a simulator and a real aircraft?

While both require specialized engineering skills, simulator maintenance focuses heavily on preserving fidelity and immersion. Unlike an aircraft, every component—from the visual system to the motion base—must be tuned to match a specific "qualification baseline" to prevent negative training transfer.

3. What is a QTG in flight simulation?

QTG stands for Qualification Test Guide. It is a set of objective validation tests run periodically (often monthly and annually) to verify that the simulator's performance—such as flight dynamics and motion cues—strictly matches the data of the real aircraft it replicates.

4. Why is predictive maintenance important for flight simulators?

Predictive maintenance uses data logging and real-time monitoring to identify potential failures (like voltage dips or hydraulic wear) before they cause downtime. This approach minimizes disrupted training slots and costly emergency repairs.

5. How do regulations affect flight simulator maintenance?

 Simulators must comply with strict regulations set by National Aviation Authorities (NAAs). Operators must maintain detailed records of all maintenance and pass both objective QTG tests and subjective evaluations by subject matter experts to retain their certification for pilot training.

6. Do flight simulators need software updates? 

Yes. Beyond hardware repairs, simulators require regular software and firmware updates to address obsolescence, fix bugs, and ensure the simulated environment (including navigation databases and terrain) matches current real-world conditions.