First of all it should be clear that the definition of "parts and appliances" (Refer to article 3 of the Basic Regulation) includes software. This is software that is installed in an aircraft and used in operating or controlling that aircraft. The rest of this response only refers to this type of software.
Secondly, "Subpart K - Parts and appliances" from Part-21 addressing installation, approval and release is applicable to this software and therefore:
- this software must be part of the design data; and
- the installation of this software in a type-certified aircraft is only accepted when it is accompanied by an EASA Form 1 and properly marked; and
- the installation is approved. (Refer to 21A.303).
In order to achieve 1) and 2), the organisation that manufactures and releases the software must meet the requirements of Subpart F or G from Part-21. This means in particular that the software must be part of the scope of that production organisation and there must be a link between the design organisation and the production organisation.
The conclusion for Field Loadable Software is therefore that this software can be delivered with an EASA Form 1 when:
- it is part of design data for which approval has been applied or granted; and.
- it is produced by, and within the scope of a production organisation that meets the requirements of Subpart F or G.
Marking of this Field Loadable Software must be in accordance with Subpart Q of Part-21. For practical reasons the marking could be on the software "container" (e.g. the CD carrying the software).