Ken Elliott discusses aircraft maintenance the different programs used to sustain it.
It is understandable to think of aircraft maintenance as just being ‘the service and repair of an aircraft’. But there’s far more to it than turning a wrench and preparing an invoice. In fact, the proper term for aircraft service is sustainment, and its primary purpose is to provide for continued airworthiness (CAW).
Sustainment for continued airworthiness includes several blocks of activity, as shown in Figure A. The complexity of sustainment is further demonstrated by its application to the different parts of an aircraft (i.e. Airframe, Cabin, Avionics, Powerplants, Auxiliary Power Unit (APU), Landing Gear, etc).
In the defense and special missions world, sustainment is also termed ‘Integrated Logistics Support’ (ILS). This is important because it highlights, within its title, three components of a successful sustainment program.
Initially, for the aircraft, there will be a period of Original Equipment Manufacturer (OEM) and vendor warranty, supported via a Maintenance Management Program (MMP), later transitioning to the current owner’s responsibility for service and tracking.
All warranty programs are limited in their coverage and may be extended in part, or replaced with a non-OEM program. The current owner may, at the time of warranty expiration, remain with the OEM for continued airworthiness services, or utilize an independent Maintenance Repair Organization (MRO).
Crucially, but not always obvious, is that the sustainment of an aircraft always remains with the aircraft and not with the owner(s). Figure B shows how the owners come and go, but the records of sustainment remain with the aircraft.
For aircraft out of warranty, understanding this simple fact is key to the ease of a future aircraft transaction. Ensuring the data and records for the aircraft remain physically as close to it (at the hangar, for example), remain current, accessible and above all, secure, will pay significant dividends at the time of a Pre-Purchase Inspection (PPI).
As with any transport that needs to operate safely and reliably, preventative maintenance is essential for aircraft. This implies proactive inspection and monitoring.
- Inspections are designed to catch issues before they mature enough to cause a failure or an event.
- Monitoring is designed to assess common data from multiple aircraft or events, to look for trends and provide corrective action.
An outcome of monitoring can lead to an Airworthiness Directive (AD) being issued. Across the world, airworthiness authorities look for common safety-related failures, events and trends.
As a rule, an AD backs-up corrective action already initiated by OEMs, as they monitor their fleets of aircraft. Mandated safety directives provide the action to take and a time limit within which to comply.
Inspection findings and equipment failures during aircraft operations lead to repairs. In some cases, repeated repairs of the same component or system can lead to modifications or bulletins (service bulletins, notices or letters).
Continued airworthiness also includes regular servicing. This is not the same as a repair and may involve the removal of a major or minor component for a check and subsequent service. Anything serviced is not considered faulty. The act of servicing is preventative maintenance, adding specific work tasks to an inspection.
Inspections and servicing are routine items that fall under calendar, flight time, or gear cycle elapsed periods of time between requirements. Repairs and modifications are non-recurrent events (hopefully) and, apart from the need to record the event, are not tracked for next due.
The industry calls trackable events ’due items’ and it is these that maintenance management programs (MMPs) follow on behalf of operators and in support of OEMs for new aircraft.
Modifications themselves are grouped as either major or minor:
- Minor Modifications: approved via Field Approval or by utilizing a Designated Engineering/Authorized Representative.
- Major Modifications: approved via Supplemental Type Certificate (STC) or a factory-issued aircraft service change process that itself would have been previously approved under an amended Type Certificate by the OEM. (Note that an STC is always a supplemental change to the existing aircraft type certificate.)
Modifications involving equipment require the equipment to have their own certification prior to being installed on an aircraft. Any equipment certification basis can be via Technical Standard Order (TSO) or Parts Manufacturing Approval (PMA).
These are not to be confused with repair or serviceability tags that apply to the status of each individual serialized component. TSO and PMA refer to the design and manufacturing approval of the equipment type and model.
The widely-used term of ‘upgrades’ also refers to modifications and usually implies an improvement, such as changing to flat panel cockpit displays or meeting a mandated requirement, such as ADS-B Out.
Maintenance Repair Organizations (MROs)
MROs, as repair shops, are especially approved to work on aircraft, engines, APUs, Avionics and all the other sub-assemblies. They all have one thing in common: a Repair Station approval required to work on your aircraft.
If your aircraft is registered in Canada, for example, then, as an operator, check the Repair Station Certificate approval from Canada is on hand at the facility.
Repair shops need to have other approvals such as an Approved Drug Program, proof of training on the aircraft and any sub-systems they maintain, and warranty service capability under factory authorized programs.
Having the right information is also crucial and operators should ensure facilities have current manuals and instructions.
No single shop can do it all and even the best will subcontract some maintenance and service. An example could be cockpit window polishing, an art for sure. However, the prime facility is responsible for the subcontracted effort and the final ‘aircraft release’ should always reflect the result of all work completed, with each task supported by its own release.
Maintenance Management Programs (MMP)
MMPs track due items on an aircraft, including inspection, service bulletins, directives and component changes. They rely on the accuracy of the information initially provided and subsequent flight activity supplied by operators.
While complex and very useful, MMPs are basically software tracking tools common to many different industries. Aircraft subject matter experts employed to manage them are the real tool you are purchasing with a subscription. Because there are many nuances in aircraft maintenance, these analysts are key to ensuring it works for you.
MMPs do offer such extras as non-routine task tracking, inventory and work order control. As a tool they support (but do not replace) the Flight Department’s mechanic.
For Business and General Aviation, there are several major MMPs that serve OEM-new and legacy used aircraft makes and models. Some of the major players also offer extras, including:
- Procurement Resources
- Pilot Tools
- Electronic Log Books
- Non-Routine Activity Tracking
- Mobile Applications
- Work Order Tools
There are several major players in the MMP business (while many others are focused on Airlines, the Military, Operations (as opposed to maintenance), or are tailored to individual aspects, such as log books). Some of the major players are:
- CAMP Systems
- Satcom Direct-AircraftLogs
- Centurion AMS-CAMMS
- WinAir (AV-Base Systems and MPLAN Solutions)
- Pentagon 2000SQL
Separately, there are companies that focus on tracking the internal activity of the MRO, dealing with work orders, manpower, invoicing, inventory and so on. Some of the more significant companies include:
- ATP Maintenance
- TangoWare-AVM 2000
- Internal Net-Air Maintenance
OEM, MRO and Other Services
Aircraft, engines and systems manufacturers provide great programs providing risk-based parts and service support to operators at competitive pricing.
These service programs typically cover labor and material, tailored to different operator requirements. Note these service programs may sometimes include an MMP.
Bombardier Business Aircraft: Provides Smart Services offering a cost-per-flight hour maintenance program to operators. This includes Smart Parts, as well as coverage options for landing gear overhaul, cabin system components and scheduled/unscheduled labor.
For a flat enrollment fee, operators can obtain coverage for new and for aircraft with up to 20 years of service. Bombardier also offers worldwide aircraft AOG and regular support for its business aircraft fleet.
Dassault Falcon: Offers FalconCare as a comprehensive maintenance cost program that includes global support, including AOG. It provides parts and labor cost predictability for anything up to a C Inspection. Enrollment is available for both new Falcons and those undergoing their first C Inspection.
Embraer Executive Jets: Provides pay-as-you-fly, Nose to Tail Maintenance Plans for its customers under the Executive Care umbrella that includes options for engines, parts, paint and cabin.
Gulfstream Aerospace: Promotes its MyCMP (a partial CAMP Systems program) for maintenance tracking and records. However, as part of Gulfstream’s overall worldwide support it includes maintenance experts as analysts to advise operators and service centers that include its mobile repair teams (MRT), Gulfstream FAST.
Textron: Has similar programs such as ProMaintenance and Pro-PowerAdvantage, tailored to its different Hawker, Cessna, Beech and Bell groups.
Non-OEM MROs also offer various degrees of maintenance programs mostly centered on AOG and Mobile Repair Teams.
All OEMs and MROs dovetail into separate vendor programs for engines (i.e. Rolls-Royce CorporateCare), APUs and avionics. Meanwhile, companies such as JSSI and Engine Assurance Program (EAP) offer independent programs covering tip-to-tail and engines, respectively. These are not aligned to OEMs and MROs, and prove highly popular in the industry.