NOTES TO CONSOLIDATED FINANCIAL STATEMENTS OF AMERICAN AIRLINES GROUP INC. 6. Leases Included in the table above is $226 million of operating lease cost under our capacity purchase agreement with Republic. We hold a 25% equity interest in Republic Holdings, the parent company of Republic. We lease certain aircraft and engines, including aircraft under capacity purchase agreements. As of December 31, 2018, we had 660 leased aircraft, with remaining terms ranging from less than one year to 12 years. At each airport where we conduct flight operations, we have agreements, generally with a governmental unit or authority, for the use of passenger, operations and baggage handling space as well as runways and taxiways. These agreements, particularly in the U.S., often contain provisions for periodic adjustments to rates and charges applicable under such agreements. These rates and charges also vary with our level of operations and the operations of the airport. Additionally, at our hub locations and in certain other cities we serve, we lease administrative offices, catering, cargo, training, maintenance and other facilities. The components of lease expense were as follows (in millions): 104 Year Ended December 31, 2018 Operating lease cost $ 1,907 Finance lease cost: Amortization of assets 78 Interest on lease liabilities 48 Variable lease cost 2,353 Total net lease cost $ 4,386