UK CAA CAP Documents

A CAP, or Civil Aviation Publication, is a numbered document in the UK Civil Aviation Authority's long-running publication series. The CAP series is how the CAA communicates official material to the aviation community: mandatory requirements, policy, acceptable ways of meeting the rules, guidance, standards documents, and reference material. Each publication is identified by a CAP number — for example CAP 804 on Flight Crew Licensing, or CAP 3181, the interim document for the National Private Pilot Licence (Aeroplane) — and pilots, training organizations, and maintenance organizations refer to them by number in day-to-day practice.

It is important to understand what a CAP is and is not. The binding law sits in UK statute and in the retained, UK-amended regulations such as UK Part-FCL, UK Part-MED, and the Air Navigation Order. CAP documents sit alongside that law: some carry mandatory requirements that the CAA has the power to set, while many others provide guidance and acceptable means of compliance that help operators demonstrate they meet the underlying rules. The status of a given CAP is stated in the document itself, and some older CAPs — CAP 804 among them — have moved to reference-only or archived status as their content is restructured into newer publications. A reader always has to check whether a particular CAP is current and whether it is mandatory or advisory.

The CAP series is best understood by analogy to the equivalent instruments in other systems, while remembering that the analogy is not an equivalence. In the US, the FAA issues Advisory Circulars (ACs) that provide non-binding guidance on acceptable methods of complying with 14 CFR. In the EASA system, the binding Implementing Rules are accompanied by Acceptable Means of Compliance (AMC) and Guidance Material (GM). The UK CAP series plays a comparable role for the UK framework — translating the rules into practical, referenceable guidance and standards — but it is its own national body of material with its own numbering, its own scope, and its own legal status for each document. Since the UK left the EASA system on 1 January 2021, the CAA has increasingly used the CAP series to publish UK-specific guidance that no longer tracks EASA AMC and GM. Because the rulebooks are diverging, a CAP cannot be assumed to mirror the corresponding EASA or FAA guidance, and citing the wrong system's document is a common source of confusion for operators working across borders.

For UK ATOs, flying clubs, and maintenance organizations, CAP documents are the practical reference layer that sits between the raw regulation and the operation's own manuals. A training organization building or updating its procedures needs to be working from the current CAP for the licence or activity in question — not an archived version, and not the FAA or EASA equivalent, which may say something materially different.

Because individual CAPs are revised, re-issued, and sometimes archived on their own timelines, keeping internal procedures aligned to the right edition is ongoing work. An operator citing a superseded CAP, or applying EASA guidance to a UK-registered activity, can end up with manuals and checklists that no longer reflect what the CAA actually requires — a quiet compliance drift that only surfaces at audit.

Aviatize's Compliance & Auditing and Digital Data & Records modules give a UK operator a single place to hold the procedures, checklists, and documented processes that reference the applicable CAPs, with version history so it is clear which edition an internal document was built against. When a CAP is revised, the affected procedures can be found and updated rather than left to drift.

Because the platform links pilot, aircraft, and training records to the compliance framework they belong to, an operator can keep UK CAP-based requirements distinct from FAA or EASA guidance across a mixed fleet or membership — reducing the risk of applying the wrong system's rules to a given activity.