Rolls-Royce, a worldwide provider of power systems and services for use on land, sea and air, operates in four global markets – civil aerospace, defense aerospace, marine and energy. Its customer base includes airlines, corporate and utility aircraft and helicopter operators, armed forces, navies, and energy customers. Rolls-Royce's aerospace units manufacture commercial and military gas turbine engines. In the U.S., the company makes engines for corporate jets, helicopters, and turboprop aircraft. Rolls-Royce also builds and installs power generation systems and marine propulsion systems.