De-Modification: Removal of the Supplemental Type Certificate modification

Jun 01, 2021


Every airlines operator who has had to remove a Supplemental Type Certificate modification from their aircraft will have a deep appreciation for the complexity involved. De-modification as it’s known, also presents significant challenges to lessors and modifiers. As our experts confirm, the process is complicated, but is also manageable through best practices. Complexity is inherent for a variety of reasons, not the least of which is the necessity to maintain safety and airworthiness, but there are others. The level and type of de-modification required, the terms of the lease agreement, and post de-modification validation requirements are all important drivers for a thorough modification.

Reasons for Supplemental Type Certificate Modification Removals

There are many reasons why an aircraft modification might be removed. For example, there may be a requirement to return the aircraft in a pre-modified configuration. The lessor may want to preserve the aircraft’s asset value, or cater to the next operator’s preferences. Perhaps they want to reduce maintenance tasks, or maintain OEM warranties. And with a more strategic mindset, the de-modification could be included within the initial modification approval. This would limit validation complications and transferability hurdles in the event of an aircraft transfer as the de-modification would be validated simultaneously.

We advise that pre-planning and strong communications amongst all stakeholders can significantly streamline a lengthy and intricate process. Our IAMA standards, including strong and early communications about proposed modifications, helps alleviate the pain upfront, and helps make a de-modification much more efficient.

So why can a de-modification of an aircraft modification be so complicated?

We identify two fundamental reasons when looking into aircraft modifications. First, the extent of the de-modification required can vary greatly, and second, its classification—major or minor—is also a factor. Some de-modifications may be as simple as deactivating functions. Deeper undertakings can include complete removal, extensive repairs, and/or OEM parts replacement.

Recognizing all of this background, we have developed rules to help operators and lessors successfully achieve a de-modification while avoiding many pitfalls. The IAMA standards incorporated in our Rulebook requires member modifiers to work with the operator and lessor starting at the RFP phase. The central takeaway is for the stakeholders to agree up- front on the level of de-modification. In the ideal world, the expectations of the lessor, operator and modifier are all aligned, and the whole lifecycle of an aircraft modification is considered from the start. This forward-looking strategy streamlines future activities. So, it makes sense for the stakeholders to be looking at how a de-modification package may be integrated into the modification right from the initial concept and RFP.

Additionally, operators and lessors can avoid added stress by taking note of some finer details. For example, while the 100% removal of an aircraft modification is clearly possible, from a paperwork and records-keeping perspective it is not. Knowing how to avoid potential surprises, such as the validation requirement when transferring an aircraft to a new aviation authority, is a basic but important insight. This is why our IAMA standards addresses Supplemental Type Certificate de-modifications early in the design process.

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