HTF7000 Engine Maintenance

View our brochure for HTF7000 Engine Maintenance

HTF7000 Engine Maintenance Services:

                 Keeping your aircraft’s engine running at its best is of utmost importance for operators. It’s important for operators to understand the three maintenance authorization levels so they can choose the right authorized maintenance, repair and overhaul (MRO) provider to handle their engine needs at any given time.

For the HTF7000 family of high performance turbofan engines, Honeywell issues its Channel Partners one of three levels of authorizations: Line, Minor or Heavy. The level of authorization specifies what types of repair and maintenance a MRO is certified by Honeywell to complete on the engine.

  • Line Maintenance Authorization

Line Maintenance Authorization is the lowest level of authorization that Honeywell grants to an MRO. With a Line Maintenance Authorization, a Honeywell channel partner has permission to perform maintenance external to the engine, as well as services that don’t require disassembly of the engine, its turbomachinery or internal engine components. For example, a Line Authorized MRO can remove and replace the engine and replace line units, like the fuel control and oil pump.  Additionally, a Line Authorized MRO is authorized to handle flight line and transient services, such as minor inspections, make oil and filter changes, remove and replace the engine, and remove and replace line replaceable units, accessories and components.

One of the things that makes the HTF7000 engine unique is that these activities can be accomplished with tools normally found in a technician’s tool box.

  • Minor Level Authorization

Many operators assume “Minor level” is the lowest level of maintenance authorization. That is not the case.  MROs at this level are authorized to perform more complex engine maintenance and repair work. At this authorization level, engine service centers can perform any of the services a Line Authorized MRO can, as well as complete engine hot section disassembly, reassembly and repair capabilities and the 4000/4800-hour digital video borescope inspection. Minor level Authorized service centers can access every bearing and every seal in the HTF engine product line. Minor level Authorized service centers can also perform the 8000/9600-hour digital video borescope inspections. Duncan Aviation is a Honeywell-authorized MRO in the United States awarded Minor Level Authorization.

 “At National Flight , we’re authorized to inspect and maintain the HTF7000 hot section,. “We’re also able to perform 4,000/4,800 hour inspections and repairs, 8,000/9,600-hour digital video borescope inspections and unscheduled maintenance at our state-of-the-art MRO center in Toledo, Ohio,  at our full-service airframe facilities in Ohio . 

Some of the other capabilities a Minor Authorized MRO has included: a hot-section signoff, replacing turbine wheels, re-blading turbine wheels replacing the combustors and performing a wide range of other complex service and maintenance activities. They also can perform gearbox inspections and component troubleshooting, removal and replacement.

  • Heavy/Overhaul Maintenance Authorization

A Heavy/Overhaul maintenance authorization is Honeywell’s highest maintenance authorization for the HTF7000 engine. At this level, an MRO provider is authorized to perform all the services of a Line or Minor Authorized MRO, but are the only providers with the authority to perform a complete engine overhaul.

In addition to disassembling, inspecting, repairing and reassembling the engine, a center with heavy/overhaul maintenance authorization can test the engine. Engine testing requires a specially equipped test cell.


National Flight Services offers one facility within the United States to serve your engine maintenance and repair needs.


10971 East Airport Service Road
Swanton, Ohio 43558
Toll Free: 1 (800) 669-2704
Local: 1 (419) 865-2311
Fax: 1 (419) 866-8322


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