The role of Operational Suitability Data (OSD) in aircraft certification

What is Operational Suitability Data?

Operational Suitability Data (OSD) is a set of aircraft-specific information developed by the manufacturer as part of the type certification process. Its purpose is to ensure operators, pilots, cabin crew, maintenance personnel and training organisations have the documentation needed to safely and efficiently operate an aircraft.

Now mandatory under European Commission regulations, OSD covers a wide range of operational areas, including pilot training, simulator qualification, maintenance certifying staff requirements and handling procedures. While an aircraft itself may be technically certified, entry into service depends on the relevant OSD being approved and available to operators and training providers.

It is critical that manufacturers consider OSD requirements early in the certification programme. If relevant flight test data is not planned from the outset, important evidence for simulator qualification, pilot training or operational assessment may be missed, leading to delays and additional cost later in the programme.

What areas are most affected by OSD?

One of the most significant areas affected by OSD is flight simulation. Under EASA requirements, simulator-related OSD defines the aircraft validation source data needed to support objective Flight Simulation Training Device (FSTD) qualification. This includes the data used to demonstrate that a system accurately represents aircraft behaviour. If the correct data is not collected during flight testing, simulator qualification can become significantly more difficult.

OSD also defines pilot training requirements. When a new aircraft, variant or modification changes how pilots work, training requirements may also need to change. This can include new avionics, updated cockpit displays, altered handling characteristics or new operational procedures. While not every change requires dedicated flight testing, many still rely on aircraft behaviour data to support training assessments and simulator validation.

Maintenance is another key area. OSD includes Maintenance Certifying Staff Data (MCSD), which determines whether maintenance personnel require a specific aircraft type rating, as well as if an existing rating can cover a new variant and what training syllabuses must include. These decisions directly affect operators preparing an aircraft for entry into service.

Why is OSD important?

The consequences of having a poorly coordinated or incomplete OSD can be significant. Manufacturers may face repeated flight tests, unusable or missing data, simulator qualification delays, postponed pilot training and ultimately delayed certification. In many cases, these issues are not caused by technical problems with the aircraft itself, but by gaps in planning and coordination between activities.

Well-structured and reusable flight-test data has become central to achieving certification. Authorities and applicants now expect stronger traceability between aircraft configuration, flight-test evidence, simulator data and operational procedures.

This is where Aeroset Technology can help. While Aeroset does not produce or approve OSD itself, we support the collection and organisation of the flight-test evidence needed to support operational suitability discussions. Most commonly, this involves gathering aircraft behaviour data relevant to pilot training or simulator qualification activities.

How does Aeroset help customers?

Aeroset supports flight-test planning and execution, aircraft sourcing, campaign coordination, instrumentation planning, manoeuvre definition and test-card preparation. The company also coordinates between aircraft owners, pilots, Approved Maintenance Organisations (AMOs), Design Organisations (DOAs), and other stakeholders involved in a campaign.

Customers typically approach us when they lack the internal resources to manage complex flight-test campaigns efficiently. Common challenges include sourcing suitable aircraft, coordinating multiple organisations, defining test requirements, installing temporary instrumentation and managing the overall project structure.

How is the role of OSD evolving?

The role of OSD will continue to grow as aircraft become more automated and new categories such as eVTOL and hybrid-electric aircraft enter service. AI and simulation technologies will help improve analysis and preparation, but they will not replace real aircraft evidence. Instead, they will make flight-test programmes more efficient and improve how certification data is managed and reused across the wider process.