Bringing expert assistance to certifying derivative aircraft for military duty

certifying derivative aircraft


Aircraft manufacturers need to fully appreciate the repercussions – in time and money – of not having a comprehensive grasp of the steps involved in certifying the airworthiness of commercial derivative aircraft. Missteps can be costly, with delays running into years and costs rising to hundreds of millions of dollars. Having a trusted and independent partner, one deeply familiar with both the aircraft and the process, becomes crucial to certification success.


Regulations change and so do the aircraft as the underlying commercial model evolves. The twin-engine Boeing Airborne Early Warning and Control aircraft (AEW&C), a heavily modified version of the 737, illustrates this point. An AEW&C built today is modified from a far different 737 than one 15 years ago, so the British version isn’t an exact replica of one the Australians certified. Each country has its own particular requirements and regulators for the aircraft: the U.S. Federal Aviation Administration (FAA), U.K. Military Aviation Authority (MAA), Australia Defence Aviation Safety Authority (DASA), South Korea’s Defense Acquisition Program Administration (DAPA) and on and on.

Different regulators, countries, standards and processes all work to ensure the safety of the plane, the crew and the public. There’s much variation to contend with when certifying a derivative aircraft, and it’s not something these special models go through every day.

Putting a massive radar system atop a commercial aircraft necessitates a new or updated supplemental type certificate (STC) and proof of airworthiness. The same is true when you beef up the landing gear, decide to operate the aircraft differently than previously, and make countless other changes. Recognizing and documenting each modification, conducting tests and making an airworthiness case to regulators can take years. And time is money.


Successful, cost-effective certification requires establishing the proper project scope. That includes determining how to maximize the existing aircraft certifications to reduce new work and cost.

At SeaTec, we know the differences in roles, configuration, usage and armaments that come into play. With that background, our engineers and consultants can document the original STC, the original accepted certification authority, the aircraft service history and many other incredibly detailed areas that must be covered when seeking new certification. Then, knowing the aircraft as we do, we report on the new, specific changes requiring certification.

Our project teams plan, prioritize and communicate with stakeholders, giving you the advantage of an independent, impartial voice in the process, one that’s less susceptible to internal pressures that regulators trust.