Rockwell Collins signed on the 1,500th business aircraft for its Corporate Aircraft Service Program (CASP) this week, the company said yesterday. The agreement was coordinated by Germany-based Rheinland Air Service, a Rockwell Collins-authorized dealer. CASP offers corporate aircraft operators maintenance for avionics and cabin entertainment equipment. Rentals, exchanges, component repairs, comprehensive reliability upgrades, equipment removal and refit coverage are also included, Rockwell Collins said. Customers are billed once a year based on their forecast of annual operating hours.