GM M.A.305(d)(2) Aircraft continuing airworthiness record system    

CAA ORS9 Decision No. 1

TASKS CONTROLLED AT COMPONENT LEVEL

(a) The maintenance schedule of the aircraft maintenance programme may include tasks controlled at component level coming from a mandatory requirement in accordance  with  Part 21 and to be performed in a workshop, such as:

(1) the removal of a component for periodic restoration to return the component to a specified standard (e.g. removal of the landing gear for overhaul);

(2) the periodic removal of a component for replacement of a sub-component by a new one when it is not possible to restore the item to a specific standard of failure resistance (e.g. discarding of universal joints of a gearbox, batteries of the escape slide/raft, discharge cartridges of fire extinguishers, etc.); and

(3) a periodic inspection or test to confirm that a component meets specified performance standards (e.g. functional check of the portable emergency locator transmitter, etc.). The component is left in service (no further maintenance action taken) on the condition that it continues to fulfil its intended purpose within specified performance limits until the next scheduled inspection.

The above tasks apply  to  ‘time-controlled  components’  as  defined  in  paragraph  (e)  of  GM M.A.305. If a component affected by a task in accordance with (2) and (3) above is controlled at aircraft level by the aircraft maintenance programme and it has not been removed since the task was last accomplished, then its status of compliance with M.A.305(d)2 is already demonstrated by the aircraft records.

Note: The maintenance in accordance:

— with (1) and (2) above assumes a predictable deterioration of the component: the overall reliability invariably decreases with age; and

— with (3) assumes a gradual deterioration of the component: failure resistance can reduce and drop below a defined level.

(b) When a component is affected by a maintenance task contained the aircraft maintenance programme (AMP) that is recommended by the design approval holder (DAH) and controlled at component level, although such component does not qualify as a time-controlled component, the status of the component may be needed to show that all the maintenance due on the aircraft according to the aircraft maintenance programme has been carried out. There is no a specific requirement to keep the CAA Form 1 or equivalent or any other detailed maintenance records.

(c) For aircraft maintenance programmes developed under a primary maintenance process- oriented methodology (e.g. Maintenance Steering Group), the term ‘time-controlled component’ pertains to ‘Hard Time’ and ‘On-Condition’. The primary maintenance processes are:

(1) Hard Time

This is a preventive process in which known deterioration of a component is limited to an acceptable level by the maintenance actions which are carried out at periods related to time in service (e.g. calendar time, number of cycles, number of landings). The prescribed actions restore the component utility margin to the applicable time limitation.

(2) On-Condition

It is a preventive process in which the component is inspected or tested, at specified periods, to an appropriate standard in order to determine whether it can continue in service. The purpose is to remove the component before its failure in service.

(3) Condition Monitoring

This is a process in which a parameter of a condition in a component (vibration, temperature, oil consumption, etc.) is monitored to identify the development of a fault. The purpose is to remove the component before its failure in service (e.g. due to related repair costs), but they are permitted to remain in service without preventive maintenance until a functional failure occurs.

Note: For components that are not subject to any of these primary maintenance processes, corrective maintenance is carried out after failure detection and is aimed at restoring components to a condition in which they can perform their intended function (‘fly-to failure’).

(d) The following table provides a summary of the records’ requirements related to components subjected to primary maintenance process, including components without an CAA Form 1 in accordance with 21.A.307 (c):

 

 

	Primary maintenance process	Continuing airworthiness records
Life-limited part		— Current status (M.A.305(d)(1)); — In-service history record (M.A.305(e)(3)(i)); — CAA Form 1 and detailed maintenance records for last scheduled maintenance and subsequent unscheduled maintenance (M.A.305(e)(3)(ii)), including modifications and repairs (M.A.305(e)(2)(ii)).
Time- controlled component	Hard time	— Current status (M.A.305(d)(2)); — CAA Form 1 and detailed maintenance records for last scheduled maintenance and subsequent unscheduled maintenance (M.A.305(e)(3)(ii)), including modifications and repairs (M.A.305(e)(2)(ii)).
	On condition	— Current status (M.A.305(d)(2)); and — CAA Form 1 and detailed maintenance records for last scheduled maintenance and subsequent unscheduled maintenance (M.A.305(e)(3)(ii)) If the task is controlled at aircraft level, the above information could be already contained in the records related to the aircraft maintenance programme (M.A.305(c)(3) and M.A.305(e)(2)(iii)). If the maintenance was performed off wing, the CAA Form 1 needs to be kept.
Condition monitoring		The CAA Form 1 does not need to be kept unless this is the means to fulfil another requirement; for example, an AD compliance.
ELA 2 aircraft: any component that is fitted without an CAA Form 1 in accordance with 21.A.307 (c)		The certificate of release to service and owner’s acceptance statement (M.A.305(e)(3)(iii)).