Published On : September 2026
Two operators can commission what looks like identical modification work and end up with entirely different commercial outcomes, because the business model they contract under determines who owns the resulting Supplemental Type Certificate (STC). Ownership decides who can reuse the design, who can license it to others, who carries the obligation to support it in service, and who captures the value if the same modification is later wanted by another operator. Anyone evaluating providers in the global aircraft STC production market is really choosing between ownership structures as much as between engineering teams.
This report separates the question into two dimensions. Nine service models describe what work is actually performed: engineering design, certification consulting, STC development, delegated authorisation services, installation kit manufacturing, aircraft integration, prototype development, airworthiness support and continued certification support. Five business models describe how that work is contracted and who holds the resulting approval.
The distinction matters because the same service can appear under several business models. Engineering design performed within a turnkey programme, engineering design sold as a standalone service to an operator running its own certification effort, and engineering design performed to extend a design the provider already owns are the same technical activity with three quite different commercial meanings.
Operators who treat the two dimensions as one tend to make avoidable mistakes, most commonly discovering after the fact that they funded development of an approval they do not own and cannot reuse across a later fleet addition. The clearest way to avoid that outcome is to settle the ownership question at the start, before scoping the technical work.
Engineering design is the foundational service in this market: defining the modification, substantiating that the design is sound, and producing the data package that describes it. It is the largest single component of effort in most programmes and the capability operators most often assume they are buying when they engage a provider.
Certification consulting sits alongside it and addresses a different problem. Rather than designing the modification, it addresses how the approval effort should be structured, what route through the framework fits the change, and how the programme should be sequenced. Operators running their own certification effort frequently buy consulting without buying design, particularly where they hold engineering capability internally but lack programme experience.
STC development is the category describing the full effort of taking a modification from concept through to an issued approval. It is the largest service category by value in this market, because it encompasses the design work, the substantiation, the data package, the authority interaction and the iteration between them. Most operators who describe themselves as buying an approval are buying this.
The three categories are frequently sold together but priced and scoped separately, and the boundaries between them are where programme disputes most often arise. A provider engaged for design but not development may complete excellent engineering and still leave the operator holding an unresolved approval effort, which is why scoping which of the three is actually being purchased matters more than it initially appears.
Delegated authorisation services are sold by organisations holding authority to approve defined elements of certification work themselves. For an operator or a smaller engineering firm without that standing, buying access to it is often the fastest route to an approval, because it removes exposure to the authority review queue from the parts of the work covered by the delegation. What the delegation covers depends entirely on the authority that holds the delegation, which is why coverage varies between providers in ways that are not always obvious from capability statements.
This is the fastest-growing service category in the market, and the reason is schedule rather than cost. Operators consistently report that timeline certainty matters more to them than programme price, because an aircraft waiting on an approval is an aircraft not earning, and a compliance deadline missed is an operational problem rather than a financial one.
Airworthiness support and continued certification support address the period after an approval is issued. An approved design carries ongoing obligations: it must be supported in service, its documentation maintained, and changes assessed as the fleet and its configuration evolve. This work is unglamorous but genuinely recurring, and it gives providers a revenue stream that persists long after the original programme closes.
Continued certification support has become more commercially significant as approval portfolios have aged. An organisation holding many approvals across many operators carries a substantial standing support obligation, and increasingly treats it as a service line with its own economics rather than as an overhead attached to past programmes.
Installation kit manufacturing is the production side of this market and the reason the category is described as production rather than purely engineering. Once a design is approved, installing it on each aircraft requires the physical parts: brackets, wiring harnesses, structural components, panels and the assembled kit that lets an installer perform the modification consistently. Producing those kits is manufacturing work governed by the approved design.
The commercial logic of kit manufacturing is what makes it strategically important. Kit revenue recurs with every aircraft modified under an approval, while the engineering revenue occurs once. An organisation holding both the approval and the kit production capability captures value across the whole life of the design, whereas one holding only the approval captures it once.
Aircraft integration covers the work of making the modification function correctly as part of the aircraft, including the ground and flight testing required to demonstrate that it does. Integration frequently reveals interface issues that the design phase did not anticipate, particularly where the modification touches several existing systems, and providers with integration capability close that loop rather than handing the problem back to the operator.
Prototype development is where a design is first physically realised on an aircraft, and it is the stage at which engineering assumptions meet the actual condition of a real airframe. Configuration differences, prior modifications and accumulated in-service changes all surface here. Providers treat the prototype aircraft as part of the engineering programme rather than as the first installation, because the learning it produces feeds directly back into the design and the kit.
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PROCUREMENT INSIGHT Kit revenue recurs with every aircraft modified under an approval while engineering revenue occurs once, so a provider holding both the approval and kit production captures value across the design's whole life. Operators scoping only the engineering often find the kit relationship decided by default. |
Turnkey programmes are the largest business model category in this market. The provider carries the modification from design through approval to installation support, and typically holds the resulting certificate. The operator buys an outcome rather than a set of activities, which is straightforward to procure and removes coordination burden, at the cost of not owning the approval that results. Understanding how operators contract this work explains why this structure dominates despite that trade-off.
Customer-owned certification programmes invert the arrangement. The operator holds the approval and engages providers for defined parts of the effort, retaining the ability to reuse the design across its own fleet, extend it as the fleet changes, and control how it is supported. The structure requires internal capability to manage the programme and carries the obligation to support the approval in service.
The choice between them is not primarily about cost. It turns on whether the operator expects to repeat the modification. An operator equipping a large fleet, expecting to add aircraft of the same type, or treating a particular configuration as a durable competitive asset has a real case for ownership. An operator doing something once has very little.
Engineering services contracted on a standalone basis and manufacturing and installation support complete the five business models. These are typically bought by organisations that hold their own certification capability and need specific capacity or specialist competence, rather than by operators seeking an end-to-end outcome. The pattern is common among MRO organisations and larger engineering firms supplementing their own teams.
Licensing is the fastest-growing business model in this market, and the economics explain why. A provider that has already funded and obtained an approval holds an asset it can license repeatedly to operators of the same aircraft type, at very low marginal cost. The development investment is already sunk, so each additional licence is substantially margin.
For the operator, licensing removes the two things that make original development unattractive: the fixed engineering cost, which does not scale down with fleet size, and the schedule exposure of an authority review queue. A licensed design is already approved, so the operator's timeline is governed by installation rather than by approval.
The trade-off is configuration fit. A licensed design was approved against a particular configuration, and an operator whose aircraft differ may need changes to make it applicable. Where those differences are minor the change is narrow; where they are substantial, licensing can turn out to cost more than it first appeared, which is why configuration assessment usually precedes a licensing decision.
Licensing is reshaping how providers think about their approval portfolios. A portfolio that was historically viewed as the residue of past programmes is increasingly managed as a product line, with deliberate decisions about which designs to develop for reuse, which configurations to cover, and which jurisdictions to extend coverage into. That shift is one of the clearer structural changes in this market.
Nine service models are tracked: engineering design, certification consulting, STC development, delegated authorisation services, installation kit manufacturing, aircraft integration, prototype development, airworthiness support and continued certification support. STC development is the largest by value and delegated authorisation services the fastest-growing.
It is an arrangement where the provider carries the modification from design through approval to installation support, and typically holds the resulting certificate. The operator buys an outcome rather than managing a set of separate activities, at the cost of not owning the approval.
The operator holds the approval and engages providers for defined parts of the effort. This retains the ability to reuse the design across the fleet and extend it as the fleet changes, but requires internal capability to manage the programme and carries the obligation to support the approval in service.
The operator uses a design that a provider has already developed and had approved, rather than funding new development. It removes both the fixed engineering cost and the approval queue exposure, though the licensed design must fit the operator's actual aircraft configuration.
Installing an approved modification on each aircraft requires physical parts produced to the approved design: brackets, harnesses, structural components and assembled kits. That production is governed by the approval itself, and recurs with every aircraft modified under it.