The growing crisis of airport congestion, both in the air and on the ground, is stimulating interest in the concept of specialized downtown airports for carriers of short-haul traffic. These carriers principally are short takeoff (STOL) and vertical takeoff (VTOL) aircraft. Although these types of aircraft have been in use for years, manufacturers are now working on development of larger and faster short-haul aircraft. At the same time, both federal and local government agencies are studying various V/STOL-port proposals. In New York City, a 10-story 2000-ft long STOL-port with dual runway is envisioned on Manhattan's Hudson River waterfront. Los Angeles has completed a plan for a down town Metroport for V/STOL aircraft, designed to reduce noise levels by directing aircraft over freeways, and to accommodate 6 million passengers by 1980.