Part-CAO scope: a King Air, a CitationJet and the 5,700 kg line

Part-CAO covers continuing airworthiness management and maintenance of aircraft other than complex motor-powered aircraft, so the definition decides everything. For aeroplanes, an aircraft is complex if its maximum certificated take-off mass exceeds 5,700 kg, or its maximum seating configuration exceeds 19, or it is powered by a multi-engined turbojet or turbofan. The criteria are alternatives: any one makes the aircraft complex.

King Air B200: 5,670 kg, nine seats, two turboprops. It is below the mass threshold, below the seating threshold, and not jet-powered, so it is not complex and can in principle come within Part-CAO. The margin is only 30 kg, so the TCDS value for the specific variant and configuration must be verified rather than taken from the operator's documentation.

CitationJet: a twin turbofan, therefore complex regardless of its 4,700 kg mass. It cannot be managed or maintained under Part-CAO; it needs a Part-CAMO organisation for continuing airworthiness and a Part-145 organisation for maintenance.

Before any work on the King Air, the CAO's approval scope must be extended to that type, with evidence of staff competence, facilities and procedures, and the competent authority must approve the change.

Only if the review is genuinely independent and the staff meet the criteria. The airworthiness review staff must have the required continuing airworthiness experience and type knowledge, and - the critical point in a three-person organisation - must not have been involved in the day-to-day continuing airworthiness management of that particular aircraft. If the same person runs the King Air's maintenance programme, tracks its defects and controls its AD status and then reviews it, the check has no independent value.

Airfield must therefore organise the work so the review is performed by someone outside that aircraft's management, or have the review carried out by another appropriately approved organisation or by the competent authority. The review is not a paperwork exercise: it includes a documentation review (AD status, approved maintenance programme, mass and balance, records of modifications and repairs, deferred defects) and a physical survey of the aircraft, and the ARC is issued only if the aircraft is found airworthy and the programme is approved and current.

The competent authority may impose additional conditions on a very small organisation using the privilege; Airfield should confirm the expected arrangement with its authority before accepting the contract rather than after.

The aircraft is then complex and outside the Part-CAO scope. The 5,700 kg figure is a bright line, and the definition uses the maximum certificated take-off mass from the type certificate data sheet - not the operator's normal operating mass, not the mass in the lease document, and certainly not a figure rounded down to fit an approval.

The consequences are immediate and apply to every activity:

1. Airfield cannot accept the King Air under its Part-CAO approval - not continuing airworthiness management, not maintenance, not the airworthiness review;
2. The charter company needs a Part-CAMO organisation for continuing airworthiness management and a Part-145 organisation for maintenance. These may be part of the same group, but they are separate approvals with separate scope;
3. The ARC would be issued by the CAMO holding the airworthiness review privilege, or by the competent authority.

Airfield should verify the TCDS before accepting any contract, record the verification and, if the aircraft is complex, decline or restructure the arrangement. Accepting it on the assumption that a 'small turboprop' must be inside Part-CAO would be a scope violation, and any release or ARC issued would be invalid. The same check should be repeated whenever a variant or modification could change the certificated mass or seating.