at _certain` Aircraft Finance; Lease and Conditional -SAles Contract dated April 3, 1987 (the "Lease") - betWeen the Lessor•and the Lessee, (which LeaseWas-recorded by the • Federal Aviation AdMinistration [the "FAA"] on May 12, 1987 and, assigned Conveyance ,No. $7Z223)I as assigned by Letter Assignmen