Hourly Maintenance Program (HMP) is a contractual maintenance program. A predetermined hourly payment for the HMP-covered part is made for each flight hour that part has flown. This ensures that its major overhaul and/or time retirement is accomplished at the proper interval, with the parts provided by the Original Equipment Manufacturer (OEM) or their designated authorized service center. HMP covered aircraft retain a higher value because the covered parts are always qualified for restorations to a “zero” or “low-time” service life condition. There are many types of HMP.  HeliCalc® will adjust values on the four most common types; Engine, Gearbox, Engine & Gearbox, and full HMP. full HMP refers to a program that covers all major drivetrain components.  If you have a custom HMP, please enter full-life status manually in the Component Status Table for each covered part.