Building a little from the prior post where we touched on the fact that the LDND (Last Done, Next Due) expands the specifics from the AMP regarding maintenance another consideration can be the HT or Hard Time components.
While Life Limited Parts (LLPs) have a definitive lifespan, Hard Time (HT) items are less straightforward. These components don’t have a predetermined lifespan; instead, they require specific maintenance actions at defined intervals. This could be an overhaul, inspection, or even replacement, depending on the component and the OEM’s instructions.
The task list of maintenance provides an instruction such as “off wing cleaning each 10000FH” for an air conditioning pack heat exchanger” – but we need to track the part number and serial number installed on the aircraft.
This is where the maintenance task translates into the part number and serial number for tracking on the LDND and why the HT listing is so important.
Sources of Hard Time Items
The HT list isn’t static; it evolves throughout an aircraft’s life, and it needs to be updated, checked and maintained. This means that the list is managed by the CAMO and when an aircraft transitions lease or CAMO we are reliant on the prior list and technical records.
The existing Hard Time listing might be essentially “risk assessed” based on the prior CAMO jurisdiction for example. Then a sample check carried out where we review the Hard Time list Vs technical records and or physical verification; depending on the results we might accept the list or then check all items.
Leasing requirements can differ from Airworthiness remember.
OEM (Original Equipment Manufacturer): The OEM such as Airbus or Boeing provides the initial list, detailing components with predetermined lifespans based on design and expected wear.
- OEM (Original Equipment Manufacturer): The OEM provides the initial list, detailing components and their maintenance intervals. This information is often found in the aircraft’s maintenance documentation and delivery documents like the Aircraft Readiness Log (ARL) for Boeing and the Aircraft Inspection Report (AIR) for Airbus.
- Modifications (MODs) and STCs (Supplemental Type Certificates): Modifications, whether through STCs or other MODs, can introduce new HT items and the STC holders are responsible for providing updated instructions for any affected HT items.
- Operator Installed Items: Operators may install components with HT requirements, further expanding the list.
Identifying Hard Time Items in the AMP
The Aircraft Maintenance Program (AMP) is key to managing HT items. It outlines the required tasks, intervals, and procedures. However, pinpointing HT items within the AMP can be tricky. Look for clues like:
- Tasks labelled as Time Controlled Items (TCI): This often indicates an HT requirement as is the case for Airbus for example.
- Maintenance tasks requiring off-aircraft work: This can also suggest an HT item.
This is not a comprehensive review but highlights how hard time items are tracked from a task that affects a part or multiple parts that we need to track by Part Number and Serial Number.
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