This excerpt taken from the AYR 8-K filed Sep 26, 2007.
Note 16. Segment Reporting
We have two reportable segments: Aircraft Leasing and Debt Investments. We present our segment information on a contribution margin basis consistent with the information that our chief executive officer (the Chief Operating Decision Maker (CODM) reviews in assessing segment performance and allocating resources. Contribution margin includes revenue, depreciation, interest expense and other expenses that are directly connected to our business segments. We believe contribution margin is an appropriate measure of performance because it reflects the marginal profitability of our business segments excluding overhead.