As a business aircraft owner or operator, you may not know exactly which components your engine Hourly Cost Maintenance Program (HCMP) covers. Is it just the aircraft fuselage and actual engine? The nacelle (the aerodynamic engine cowl and its support system)? The nose cowls, cowl doors, and thrust reverser units? Are all line-replaceable units covered? And if so, are there any exclusions for damage such as corrosion?