Upgrade means a major version upgrade of any Platform software.
Replacement Equipment means operational equipment or other parts used by Tenant to replace any of the Equipment.
Replacement Airframe means an Airbus A321 aircraft or a comparable or improved model of Manufacturer (except (a) Engines or engines from time to time installed thereon and any and all Parts related to such Engine or engines and (b) Excluded Equipment), that shall have been made subject to the Lien of the Indenture pursuant to Section 7.05 thereof, together with all Parts relating to such aircraft.
Fireplace means all devices both masonry or factory built units (free standing fireplaces) with a hearth, fire chamber or similarly prepared device connected to a chimney which provides the operator with little control of combustion air, leaving its fire chamber fully or at least partially open to the room. Fireplaces include those devices with circulating systems, heat exchangers, or draft reducing doors with a net thermal efficiency of no greater than twenty percent and are used for aesthetic purposes.
Replacement Aircraft means the Aircraft of which a Replacement Airframe is part.