The Growing Value of Time on Wing Assessments

For airlines and engine operators, managing powerplant costs and availability has become increasingly challenging. In a market defined by constrained MRO capacity, supply chain pressures and changing trade dynamics, understanding how long an engine is likely to remain operational before a maintenance event has become more important than ever.

Planning for engine maintenance is no longer simply about scheduling the next shop visit – it is about understanding risk, ensuring spare engine availability, protecting budgets and maximising asset value.

As a result, Time on Wing (TOW) assessments have become an increasingly important part of the support TGIS Aviation provides to airlines, operators and lessors looking to improve planning, reduce risk and make more informed asset management decisions.

Whilst TOW assessments were historically focused on helping to understand an engine’s remaining life until the next shop visit, we are now seeing customers utilise them as a broader planning tool to help manage costs, anticipate risks and improve maintenance strategies in an unpredictable market.

The engine remains one of an airline’s biggest maintenance expenses. Yet maintaining control over those costs has become more difficult as MRO capacity remains constrained. Longer turnaround times, limited availability of parts and spare engines and rising component costs are creating uncertainty across the industry.

Typically, we work with airlines and operators that already have highly capable powerplant teams in place but are dealing with the realities of an exceptionally difficult market. Today’s environment requires teams to manage immediate operational priorities while also anticipating maintenance events, monitoring supply chain challenges and planning budgets further into the future.

In practice, operational requirements will always take priority, which can leave limited time and resource for managing the wider shop visit process with the level of focus and attention it requires. Yet decisions made around workscope, material sourcing, turnaround expectations and cost control can have significant long-term operational and financial implications. Our role is to work alongside internal teams, supporting and strengthening our customers’ ability to meet deadlines and make informed decisions.

A TGIS Aviation Time on Wing assessment goes beyond reviewing individual data points in isolation. We help customers build a more complete picture of an engine’s remaining utility and the factors that could influence future maintenance requirements, costs and overall asset value.

Rather than simply looking at historical information, we assess how factors such as operational profile, service history, modification standards, LLP status and performance trends interact to influence likely future outcomes and potential risk areas.

Through a TOW assessment, we help customers answer practical questions such as:

• How long is the engine likely to continue operating before major maintenance is required?
• Will the engine become limited by its physical operating condition or Life Limited Part (LLP) expiry first?
• How much useful life remains before key replacements are required?
• What maintenance events and work scopes are likely over the coming period and how can this be optimised against the “mission profile” of the engine?
• How might current market conditions affect future maintenance events and turnaround times?
• What does this mean for the value and utility of the asset?

These considerations are becoming increasingly important as engine life cycle management becomes more difficult.

Recently, we supported a TOW assessment for two CFM LEAP-1A engines for a client. In addition to providing the TOW to the next shop visit, based on the physical condition and performance of the engines, we also reviewed their operation over the remaining lease term, considering the operational environment, last workscope, modification standard and the lease return conditions.

We “flew the engines forward” to the lease return date, estimating the number of shop visits technically needed, the workscopes and LLP replacements for these shop visits, and assessed whether the engines would meet the redelivery conditions of the lease or require an additional shop visit. This comprehensive evaluation enabled the client to make informed decisions about the optimal management of its engine assets.

We are also seeing growing demand for support around the wider factors influencing engine maintenance planning. Availability of spare engines and lead time of parts remain a challenge across the industry and many components have seen significant price increases in recent years, driving up the overall cost of a shop visit. Trade tariffs, regulatory changes and broader supply chain pressures add further complexity.

For customers looking to strengthen financial planning, our senior team can also support with cost forecasting and budget modelling, helping create greater visibility around potential future expenditure. This can include developing a clearer understanding of the likely number of shop visits required over a given period, the expected work scope, anticipated engine modification standards and the associated costs, ultimately helping customers improve planning and gain greater confidence around future cashflow requirements.

As market pressures continue, we are finding that customers are looking for additional insight to help identify risks earlier, improve planning and maintain greater control over costs. Time on Wing assessments are a valuable part of that process.

At TGIS Aviation, we see Time on Wing assessments as far more than a technical exercise. By combining detailed engine analysis with practical asset management expertise, we help customers improve visibility, reduce uncertainty and make more informed decisions around maintenance, leasing and long-term asset value.

In today’s environment, maintaining an engine is only part of the challenge – maintaining predictability and visibility around future maintenance requirements has become equally important.