Line maintenance is the set of tasks that keeps an aircraft airworthy between flights without taking it out of service. It happens on the ramp or at the parking stand, and almost always against the clock. The aircraft has a departure time, and the work must be finished, documented and certified before it.
In this article we review what line maintenance includes, which regulations govern it, and how a specialised cloud ERP helps manage it with order and traceability.
What line maintenance includes
There is no single, closed list. Each organisation defines its scope in its Maintenance Organisation Exposition (MOE), and each operator specifies it in its Aircraft Maintenance Programme (AMP). Even so, line maintenance usually covers the following tasks.
Transit checks and pre-flight checks
These are visual and operational inspections performed at every turnaround or before the first flight of the day. The technician checks the general condition of the aircraft and looks for visible damage, leaks, tyre and brake wear, fluid levels and the operation of basic systems. They take minutes, but they are the first barrier against a problem.
Daily checks and weekly checks
Daily checks are normally performed every 24 or 48 hours, depending on the approved programme. Weekly checks go a little deeper: they cover items that are not inspected at every turnaround, such as certain compartments, emergency equipment or oil levels in secondary systems.
A-checks
The A-check is the lightest scheduled inspection in the lettered check cycle. Its interval depends on the aircraft type and the operator's programme, and is expressed in flight hours, cycles or calendar time. Many organisations perform it as line maintenance, often overnight. Others treat it as base maintenance. The classification depends on the organisation's approved scope.
Defect rectification and the MEL
A large part of the daily work is rectifying defects reported by the crew in the tech log. When a defect cannot be fixed before departure, the operator can defer it if the Minimum Equipment List (MEL) allows it. The deferral has a time limit, conditions and (O) and (M) procedures that must be followed and recorded.
Other common tasks
- Replacement of easily accessible components (LRUs).
- Servicing: fuel, oil, oxygen, potable water.
- Short-interval inspection programme tasks.
- Embodiment of simple airworthiness directives (ADs).
Regulatory framework: EASA and FAA
EASA: Part-145, Part-M and Part-CAMO
In Europe, Regulation (EU) No 1321/2014 governs continuing airworthiness. Its key annexes for line maintenance are:
- Part-145 (Annex II): approves the organisations that perform maintenance. A Part-145 organisation can hold an approval for line maintenance, base maintenance or both. Each line station must be listed in its MOE.
- Part-M (Annex I): defines responsibilities for the continuing airworthiness of the aircraft. The approved maintenance programme comes from here.
- Part-CAMO (Annex Vc): governs continuing airworthiness management organisations, typically within airlines. The CAMO plans; the Part-145 organisation executes.
- Part-66: sets out the licences for certifying staff. B1 and B2 categories are common on the line, and in some cases category A for minor tasks.
After each intervention, certifying staff issue a Certificate of Release to Service (CRS). Without a CRS, the aircraft cannot fly.
FAA: 14 CFR Part 145 and Part 43
In the United States, repair stations are certificated under 14 CFR Part 145. Part 43 defines how maintenance is performed and recorded, including approval for return to service. Operator responsibilities depend on the operating rules that apply (for example, Part 121 or Part 135). The FAA has no equivalent "Part-M" under that name: that concept belongs to the EASA framework.
Many organisations work under both frameworks at once because they serve European and US operators. This doubles documentation requirements and demands precise control of which rule applies to each aircraft.
The real challenges of line maintenance
Technicians and station managers know these problems well:
- Short, unpredictable ground times. A late arrival reduces the available time. An aircraft swap changes the whole night's plan.
- Scattered information. The tech log, deferral status, station stock and availability of certifying staff often live in different systems or documents.
- Paper on the ramp. Paper task cards get lost, get wet or are signed illegibly. Later, someone in the office transcribes them, with a risk of errors.
- Deferral control. An expired MEL deferral is a serious finding. Tracking time limits by hand, across several aircraft and several operators, is fragile.
- Multiple customers. A line station may serve several operators, each with its own programme, forms and procedures.
How a cloud ERP supports line maintenance
A specialised aviation ERP does not replace the technician's judgement or the responsibility of certifying staff. Its job is different: to get the right information to the right person at the right time, and to make sure everything is recorded.
Ground time management
The system links the flight schedule to the open tasks for each aircraft. The shift lead sees which aircraft are arriving, how long they will be on the ground and what work is assigned. If a flight is delayed, they can reorder tasks or reassign staff based on real data, not assumptions.
Digital work orders
Each intervention is opened as a work order with its scope, aircraft, customer and status. The work order groups the task cards, consumed materials, booked hours and defects found. When it closes, all the information is already in the system. Nothing needs to be transcribed.
Task cards on the technician's device
With a cloud ERP, the technician opens the task card on a tablet or phone next to the aircraft. They record completed steps, attach photos of a finding and sign with their own user. The system checks that the person signing holds the right authorisation for that task and that aircraft type.
Defect and deferral control
Deferred defects are recorded with their MEL reference, category and due date. The system warns before expiry, so the station manager can plan the rectification before the deferral becomes a problem.
Stock and tooling at the station
Knowing what is in the station store avoids waiting and cancellations. An ERP connects inventory with work orders: the technician reserves the part, the system records the consumption, and the component's traceability (part number, serial number, certificate of conformity) is linked to the intervention.
Access from any station
Because it is cloud-based, the system works the same at the main base and at a remote outstation. There is no need to install servers at every airport. Technical management sees the status of every station in real time.
What to look for in an ERP for line maintenance
Before deciding, assess these points:
- Support for your regulatory framework: EASA, FAA or both.
- Mobile use: the ramp is not an office.
- Certifying staff authorisation control built into sign-offs.
- Full traceability of components and materials.
- Multi-customer management, if you serve several operators.
- Ease of implementation and support during data migration.
Conclusion
Line maintenance demands speed without giving up rigour. Every task must be planned, performed by authorised staff and documented in a way that stands up to an audit. A specialised cloud ERP reduces administrative work and leaves more time for what matters: the safety of the aircraft.
SkyPlannerHub is a cloud ERP built for aviation maintenance organisations: line maintenance, base maintenance, and component and engine MRO. If you want to see how it fits your station's operation, get in touch and we will review it with you.