Exhibit 11.1 Computation of Earnings EXHIBIT XI WILLIS LEASE FINANCE CORPORATION Computation of Earnings Per Share Three Months Ended September 30 Nine Months Ended September 30 ------------------------------- ------------------------------ Income/(loss) before extraordinary item 1999 1998 1999 1998 -------------- -------------- -------------- -------------- (in thousands, (in thousands, except per share data) except per share data) Basic Earnings: Income/(loss) before extraordinary item ($4,384) $2,484 $1,190 $6,583 Shares: Average common shares outstanding 7,394 7,280 7,377 7,245 -------------- -------------- -------------- -------------- Basic earnings/(loss) per common share before extraordinary item ($0.59) $0.34 $0.16 $0.91 Assuming Full Dilution Earnings: Income/(loss) before extraordinary item ($4,384) $2,484 $1,190 $6,583 -------------- -------------- -------------- -------------- Shares: Diluted average common shares outstanding 7,448 7,495 7,447 7,466 -------------- -------------- -------------- -------------- Earnings/(loss) per common share assuming full dilution, before extraordinary item ($0.59) $0.33 $0.16 $0.88 -------------- -------------- -------------- -------------- Net income/(loss) Basic Earnings: Net income/(loss) ($4,384) $2,484 $1,190 $6,383 -------------- -------------- -------------- -------------- Shares: Average common shares outstanding 7,394 7,280 7,377 7,245 -------------- -------------- -------------- -------------- Basic earnings/(loss) per common share ($0.59) $0.34 $0.16 $0.88 Assuming Full Dilution Earnings: Net income/(loss) ($4,384) $2,484 $1,190 $6,383 -------------- -------------- -------------- -------------- Shares: Diluted average common shares outstanding 7,448 7,495 7,447 7,466 -------------- -------------- -------------- -------------- Earnings/(loss) per common share assuming full dilution ($0.59) $0.33 $0.16 $0.85 -------------- -------------- -------------- -------------- Supplemental information: Difference between average common shares outstanding to calculate basic and assuming full dilution is due to options outstanding under the 1996 Stock Options/Stock Issuance Plan and warrants issued in conjunction with the initial public offering