For production flight tests for aircraft containing unapproved design elements, can approval of the Flight Conditions be performed solely under the TC Holder’s DOA?
Answer
Newly-produced aircraft are usually initially flown under a Permit to Fly (PTF) to perform production flight tests, enable the transfer of the aircraft to a completion centre and to eventually deliver the aircraft to the customer. If such aircraft fully conform to an already approved design, 21.A.710(b) indicates that approval of the Flight Conditions (FCs) associated to the PTF is not related to the safety of the design.
However, the configuration of newly-produced aircraft required to be flown often includes concessions or changes to type design yet to be approved. 21.A.710(a) indicates that the approval of FCs associated in this context is related to the safety of the design and that such an approval then needs to be made either by the Agency or by an appropriately approved design organisation.
TC holders usually hold both a DOA and a POA with respective FC and PTF privileges. For newly-produced aircraft with unapproved concessions or design changes, it is clarified that it is NOT necessary that two separate kinds of approvals of FCs are required to be issued by the TC holder, i.e. approval of the FCs for the aspects not related to the safety of design under their POA and approval of the FCs for the aspects related to the safety of design under their DOA. It is acceptable and sufficient that approval of FCs for such flights is performed solely under the DOA.
The approval of FCs related to the safety of design for newly-produced aircraft can also potentially be more efficient by the TC holder defining and approving an "envelope" of FCs under the DOA, including flight purposes related to the safety of design and not related to the safety of design, to cover the set of flights required to be performed by the design organisation and the production organisation, respectively. These FCs could remain valid provided that in between each flight the only changes relevant to the aircraft configuration is the approval status of the design (i.e. proceeding from unapproved to ultimately fully approved). However, if there are changes to the physical configuration of the aircraft during the testing, limitations or conditions may change and the FCs would need to be reassessed and possibly reissued to reflect the incorporated changes to the configuration.
When the design of the aircraft is already fully approved before the first flight, the FCs need to be approved under the POA or by the Competent Authority. Within companies holding both the DOA and POA, the same staff could be nominated to approve the FC under either DOA or POA privileges as applicable.