over a fixed 17-year period and is calculated using an 8.85% interest rate.  

 

While the Pension Protection Act makes our funding obligations for these plans more predictable, factors outside our control continue to have an impact on the funding requirements. Estimates of future funding requirements are based on various assumptions and can vary materially from actual funding requirements. Assumptions include, among other things, the actual and projected market performance of assets; statutory requirements; and demographic data for participants. For additional information, see Note 10 of the Notes to the Consolidated Financial Statements.  



Recent Accounting Standards  

 

Revenue Arrangements with Multiple Deliverables. In October 2009, the Financial Accounting Standards Board ("FASB") issued ASU 200913. The standard (1) revises guidance on when individual deliverables may be treated as separate units of accounting, (2) establishes a selling price hierarchy for determining the selling price of a deliverable, (3) eliminates the residual method for revenue recognition and (4) provides guidance on allocating consideration among separate deliverables. It applies only to contracts entered into or materially modified after December 31, 2010. We adopted this standard on a prospective basis beginning January 1, 2011. We determined that the only revenue arrangements impacted by the adoption of this standard are those associated with our SkyMiles Program.  

 

Fair Value Measurement and Disclosure Requirements. In May 2011, the FASB issued "Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRSs." The standard revises guidance for fair value measurement and expands the disclosure requirements. It is effective prospectively for fiscal years beginning after December 15, 2011. We are currently evaluating the impact the adoption of this standard will have on our Consolidated Financial Statements.  

 

Supplemental Information  

 

We sometimes use information that is derived from the Consolidated Financial Statements, but that is not presented in accordance with accounting principles generally accepted in the U.S. (“GAAP”). Certain of this information are considered to be “non-GAAP financial measures” under the U.S. Securities and Exchange Commission rules. The non-GAAP financial measures should be considered in addition to results prepared in accordance with GAAP, but should not be considered a substitute for or superior to GAAP results.  

 

The following tables show reconciliations of non-GAAP financial measures to the most directly comparable GAAP financial measures.  

 

We exclude the following items from CASM to determine CASM-Ex:  

 

•	Aircraft fuel and related taxes. Management believes the volatility in fuel prices impacts the comparability of year-over-year financial performance.  

 

•	Ancillary businesses . Ancillary businesses are not related to the generation of a seat mile. These businesses include aircraft maintenance and staffing services we provide to third parties and our vacation wholesale operations.  

 

•	Profit sharing. Management believes the exclusion of this item