How does aircraft test data turn into a flight simulator?

Accurate flight test data is fundamental to building a high-fidelity flight simulator. Collected during aircraft testing, these insights cover the measurements and performance parameters used to evaluate an aircraft’s handling characteristics and operational efficiency. These findings are then translated into the models and behaviours that underpin simulator development.

The quality of flight test data plays a critical role in certifying a training device. It often determines whether qualification is achieved efficiently or becomes a lengthy, complex process, potentially resulting in qualification limitations or restrictions.

How is flight test data collected?

Before flight test data can be used to build a simulator, it first needs to be collected from the aircraft itself. This typically takes place during dedicated flight test campaigns, where engineers work alongside pilots to fly a series of planned manoeuvres designed to evaluate specific aircraft characteristics and systems.

Throughout each flight, onboard instrumentation records hundreds of parameters, from pilot control inputs and engine performance to aircraft attitude, speed and altitude. The aircraft is flown under carefully controlled conditions to ensure the data accurately captures its behaviour across different phases of flight.

Every manoeuvre is documented in detail, including factors such as aircraft weight, centre of gravity and weather conditions. This level of traceability helps ensure the resulting data can later be used to support simulator development and certification activities.

Critical flight test parameters

Not all flight test data carries equal weight when developing a simulator model. Engineers rely on a broad range of variables to accurately replicate aircraft behaviour, including flight and engine control inputs such as yoke movements and throttle lever positions, aircraft attitudes, roll, pitch and yaw rates, accelerations, airspeed, altitude, engine performance data, and configuration states such as flap settings or landing gear position.

Environmental factors such as wind and temperature can also significantly influence behaviour. Capturing how an aircraft responds to these conditions is essential to ensuring a training device accurately reflects real-world performance or reacts to events such as turbulence.

Certifying data quality for simulator development

Before flight test data can be used, it must first be determined suitable for simulator development. A key requirement is that all manoeuvres specified by certification regulations have been completed correctly and under the required conditions, including aircraft configuration, weight and speed.

In Europe, these requirements are defined by the Certification Specifications for Flight Simulation Training Devices (CS-FSTD), published by the European Union Aviation Safety Agency (EASA). The regulations outline the flight test evidence, validation processes and performance standards required to demonstrate that a simulator accurately represents the aircraft it is designed to replicate.

While CS-FSTD defines the minimum flight test points required for simulator qualification, these are typically supplemented by a significant number of additional development test points. Often matching or exceeding the number of qualification test guide (QTG) points, these extra manoeuvres and scenarios allow engineers to investigate aircraft behaviour in greater depth and refine the device beyond the baseline certification requirements.

Together, the certification and development test points form the overall flight test matrix used during simulator development. While the QTG points are essential for demonstrating compliance, the additional testing is what helps transform a system from one that simply meets regulatory standards into one that delivers a more realistic and effective training experience.

Accurately tracking flight test data

Once compliant, the focus shifts to the quality of the data itself. Engineers need confidence that the information is accurate, properly synchronised and fully documented, with clear records of the conditions under which each manoeuvre was flown. This ensures the data can be traced back to the original test and reliably used during simulator development.

To achieve this, engineers compare the flight test data against flight logs, test cards and instrumentation records to confirm that each manoeuvre was flown as planned. They also verify that all recorded parameters align correctly in time and review the data for any inconsistencies or unexpected results. This helps ensure the data accurately reflects the aircraft’s behaviour before it is used to develop simulator models.

This process is carried out throughout the flight test campaign, often immediately after each test sortie. This allows engineers to confirm that all required data has been captured correctly while the aircraft is still instrumented for testing. Only once the team is confident that the complete dataset has been collected can the aircraft return to maintenance for the removal of the flight test instrumentation.

The data is then subjected to a series of quality checks, including sensor calibration, signal consistency reviews and outlier detection. These help manufacturers determine whether unusual spikes or anomalies reflect genuine aircraft behaviour or are the result of sensor issues, electromagnetic interference, atmospheric disturbances or pilot inputs.

Turning raw flight data into usable insights

Once the quality of the data has been confirmed, it must be prepared for simulator building. The data is first synchronised to ensure all measurements align correctly in time before being organised into individual manoeuvres.

This is often one of the most time-intensive stages of the process. Large volumes of flight test data must be carefully reviewed, organised and validated before they can be used to support simulator modelling. The effort invested at this stage helps meets certification requirements.

These findings form the foundation for the mathematical models that drive simulator behaviour. Engineers analyse the relationships between pilot inputs and aircraft responses using established principles of flight mechanics and equations of motion.

From these relationships, aerodynamic coefficients and system functioning logics can be estimated and incorporated into the simulator. The resulting models are then validated against independent flight test cases and fine-tuned until they accurately reproduce the aircraft’s behaviour across a range of operating conditions.

Overcoming modelling challenges

Translating real-world aircraft behaviour into a virtual environment is rarely straightforward. Engineers must account for a wide range of factors, from changing weather conditions to gaps in the available test data. They also need to ensure the simulator accurately reflects how a specific aircraft responds in different situations.

One of the biggest challenges is determining whether unusual results in the data represent genuine aircraft behaviour or simply errors in the measurements. When information is missing or incomplete, manufacturers must carefully review other available data such as gaps in airspeed readings, control inputs or environmental data. They then use their expertise and engineering judgement to fill the gaps without compromising accuracy.

Verifying simulator performance

A simulator’s performance is ultimately measured against the original flight test data from which it was derived. Engineers compare simulator outputs with recorded aircraft responses using identical inputs and operating conditions, evaluating dynamic behaviour, handling qualities, system performance and overall trends.

These comparisons must demonstrate that the simulator remains within defined tolerances and faithfully reproduces the aircraft’s behaviour before it can progress through qualification and certification processes.

The role of certification standards

Regulatory standards provide the framework that governs simulator development and qualification. Requirements such as CS-FSTD(A) for aeroplane simulators and CS-FSTD(H) for helicopter simulators define the levels of fidelity, validation evidence, documentation and objective testing needed to certify a training device for operational use.

Meeting these standards requires accurate simulator models, robust flight test data and a clearly documented validation process that demonstrates compliance throughout development.

Supporting the journey from flight test to simulator qualification

Successfully transforming flight test data into a certified training simulator requires expertise across multiple disciplines, from flight testing and data analysis to modelling and validation. Aeroset supports organisations throughout this process, providing flight test planning, instrumentation coordination, data collection, manoeuvre execution, documentation, analysis and simulator validation support.

By ensuring data quality from the outset and supporting every stage of development, Aeroset helps customers to build training devices that accurately reflect real-world aircraft performance.