slots refinancing transaction will generate more than $30 million in annual interest expense savings.  

 

Contractual Obligations  

 

The following table summarizes our contractual obligations at December 31, 2012 that we expect will be paid in cash. The table does not include amounts that are contingent on events or other factors that are uncertain or unknown at this time, including legal contingencies, uncertain tax positions and amounts payable under collective bargaining arrangements, among others. In addition, the table does not include expected significant cash payments which are generally ordinary course of business obligations that do not include contractual commitments.  

 

The amounts presented are based on various estimates, including estimates regarding the timing of payments, prevailing interest rates, volumes purchased, the occurrence of certain events and other factors. Accordingly, the actual results may vary materially from the amounts presented in the table.  

 

During 2012, our contractual obligations were impacted by our agreement with Bombardier to purchase 40 CRJ-900 aircraft with deliveries beginning in 2013 and continuing through 2014 and with our agreement with Pinnacle Airlines, Inc. to purchase 16 CRJ-900 aircraft with deliveries in 2013. Our estimated payments to purchase these aircraft are included in the obligations below. In addition, we entered into agreements with Southwest Airlines and The Boeing Company to lease 88 B-717-200 aircraft with deliveries beginning in 2013 and continuing through 2015.   

Long-Term Debt, Principal Amount. Represents scheduled principal payments on long-term debt. The table excludes amounts received from American Express for its advance purchase of restricted SkyMiles because this obligation will be satisfied by American Express' use of SkyMiles over a specified period rather than by cash payments from us. For additional information about our agreements with American Express, see Note 7 of the Notes to the Consolidated Financial Statements.  

 

Long-Term Debt, Interest Payments. Represents estimated interest payments under our long-term debt based on the interest rates specified in the applicable debt agreements. Interest payments on variable interest rate debt were calculated using LIBOR at December 31, 2012 .  

 

Contract Carrier Obligations. Represents our estimated minimum fixed obligations under capacity purchase agreements with regional carriers. The reported amounts are based on (1) the required minimum levels of flying by our contract carriers under the applicable agreements and (2) assumptions regarding the costs associated with such minimum levels of flying. 

 

Employee Benefit Obligations. Represents primarily (1) our estimated minimum required funding for our qualified defined benefit pension plans based on actuarially determined estimates and (2) projected future benefit payments from our unfunded postretirement and postemployment plans. For additional information about our employee benefit obligations, see “Critical Accounting Policies and Estimates”.  

 

Aircraft Purchase Commitments. Represents primarily our commitments to purchase 100 B-737-900ER