Who's the Installer?
Dec 22, 2025
This month, I’d like to share some observations and explanations based on the results of a LinkedIn poll we recently conducted.
The question was: Who is the “installer” of an aircraft modification?
Participants could choose between:
- CAMO / Airworthiness Manager
- Maintenance Organization / Part 145
- Owner / Operator
The results were as follows:
- 59% voted for Airworthiness Manager / CAMO (EASA)
- 35% voted for Maintenance Organization / Part 145 (EASA)
- 6% voted for Aircraft Owner / Operator
Let me start with why we asked this question. As is often the case, it originated from a real situation we experienced.
We encountered a case involving a helicopter used for overwater operations where a cargo basket was installed. The AFM Supplement for that modification clearly stated that the basket was not compatible with flotation devices—which are mandatory for overwater operations.
The Operator did not review the supplement and did not involve the Airworthiness Manager / CAMO in the evaluation of the modification. The Part-145 organization’s position was: “Not our problem — we’re doing what the Operator asked us to do.”
All of this happened while a CAA Surveyor was on site reviewing documentation for the issuance of the Certificate of Airworthiness. :-(
As you can imagine, not exactly the situation you want when the Authority is present.
In our book Introduction to Aircraft Management, we explain that a design change can introduce new airworthiness, maintenance, or operational requirements that must be integrated into the overall aircraft management system. This is why it's essential to properly evaluate any modification before installation.
Here’s an excerpt from the book:
“Most often, design change data includes the following statement (or something similar):
Prior to incorporating this modification, the installer shall establish that the interrelationship between this change and any other modification(s) incorporated will not adversely affect the airworthiness of the modified product.”
Why is this relevant to Operators, Airworthiness Managers / CAMOs, and Maintainers alike?
Because it affects everyone.
In this example, the Operator spent time and money embodying a modification that—due to the nature of the operations—could not be used. Airworthiness had to address the aircraft’s return to service and Certificate of Airworthiness issues, which delayed putting the aircraft back into operation.
Maintenance… well, in this case, they were arguably the only winners. They invoiced the Operator for the installation of the modification, additional hangar space, and manpower due to the delay in the issuance of the C of A.
Let’s analyze the poll results.
The physical installer is certainly the Maintenance Organization — however, there are a few important considerations to make.
As discussed earlier, modifications may introduce specific conditions, airworthiness requirements or operational restrictions. We’ve seen this many times before.
By conditions, we mean limitations such as—in this case — the prohibition of using flotation devices and the cargo basket together. Another condition might be the requirement to embody an additional modification before the intended one can be installed.
By airworthiness requirements, we mean additional repetitive maintenance tasks that must be added to the aircraft maintenance program and to the software used to manage and track the maintenance schedule.
Why is this important? Because aircraft are like cars: to operate them safely and ensure long-term reliability, maintenance must be performed as defined by the manufacturer. In aviation, this is not only best practice—it is also a regulatory requirement.
So, who is in the best position to make these evaluations?
The person or department managing the aircraft on a daily basis—the one most familiar with the machine.
Is that the Operator?
The Aircraft Manager / CAMO?
The Maintainer?
All answers can be valid. It depends on the operational environment.
Ultimately, regulations typically place the responsibility with the Owner / Operator of an aircraft, although the requisite actions may be discharged to other individuals / departments.
Afterall, the operator determines what role the aircraft is to be used in, and how it must be equipped and maintained. However, rarely the operator alone can make all these determinations on their own. They must engage all parties to ensure all aspects have been considered. Generally, maintainers don't have access to all maintenance records for any one given aircraft. These are typically in the hands of whoever is managing the continuing airworthiness.
Europe (EASA environment)
In Europe, EASA identified—many years ago—the concept of the CAMO (Continuing Airworthiness Management Organization). CAMOs are responsible for managing the continuing airworthiness of aircraft, which includes, but is not limited to:
- Preparing and managing the maintenance program
- Tracking flight hours and cycles
- Managing defects
- Scheduling maintenance events
- Manage the maintenance schedule
- Evaluating Airworthiness Directives and Service Bulletins, including….modifications!
Maintenance organizations are responsible for performing maintenance and supporting the CAMO when required. Other than verifying that the work they've accomplished meets a given standard, they are not responsible for making airworthiness decisions.
As for the Operator/Owner: they must have access to a CAMO, whether in-house or contracted. Any modification must be coordinated with the CAMO before installation.
North America (U.S. & Canada)
In North America, there is no CAMO concept. Regulations require the Operator to manage the airworthiness of the aircraft, but the term “CAMO” is never used.
How is this achieved?
In commercial operations, many operators have planning and engineering departments that perform functions very similar to a CAMO and they in turn interface with Maintenance—either in-house or through third-party MROs or repair stations.
Things become far less clear in private operations, for two main reasons:
- Regulations are not very specific
- Organizational structures often vary significantly
In this environment, the distinction between maintenance and airworthiness is often poorly defined. It is not uncommon to find pilots managing the entire system, sometimes without full awareness of airworthiness and maintenance requirements. As a result, they rely heavily on the repair station or MRO to “take care of everything.”
It's critical to understand that maintenance organizations have no regulatory obligation to manage the airworthiness of your operation. They do what they are instructed to do—unless a contract explicitly states otherwise—even if you’ve been using the same maintenance provider for years.
OEM maintenance facilities
The situation can be different for private aircraft maintained exclusively at OEM facilities. For example, a new Gulfstream maintained at Gulfstream facilities will typically receive a more integrated “airworthiness treatment.” These facilities have the most extensive knowledge of the aircraft type and are much more intimate with client aircraft as they maintain comprehensive records of all work performed.
As I’ve said many times before: the environment determines your operational reality.
The key takeaway is this: responsibilities must be clearly defined—and documented—in a contract.
Regardless of where or how you operate, continuing airworthiness must be actively managed. Make sure you know exactly who is responsible.
Finally, instead of relying solely on labels, focus on functions, especially when working across different regulatory environments. (I explored this topic further in a previous article, which you can read here: https://www.cacglobalsolutions.com/blog/aircraft-management-company-versus-camo)
I sincerely hope you’ve enjoyed our articles this year and that they have, in some way, supported and enhanced your role in the aviation industry.
See you in 2026 with more articles!
Annalisa - Aircraft Management Specialist, Co-Author of "Introduction to Aircraft Management"
