Can a Type Certificate Holder (TCH) Split Part-21 Responsibilities Between Its Own DOA and Another DOA Holder (DOAH) on a Project-by-Project Basis?
Answer
No, the regulatory framework does not permit the discharging of the obligations of the TCH to be divided between different DOAs on a project-by-project basis.
When a TCH has obtained their own DOA and they decide to fulfil the obligations as TCH using this DOA they need to do so in full.
As a result, a TCH cannot apply a mixed compliance model whereby:
- for certain projects, it discharges its obligations under point 21.A.44 directly through its own DOA; and
- for other projects under the same TC, it contracts another organisation to discharge those same obligations on its behalf under point 21.A.2.
A project-based allocation of the same TC responsibilities between different organisations is not permitted, as it would undermine the clear assignment of accountability required by Part-21 and could give rise to safety concerns. The single DOA in charge will be able to maintain a 100% overview and be responsible for the Continued Airworthiness, configuration control and other matters concerning airworthiness.