[5] Houston Metro Airlines constructed their own 2,500 foot, short take-off and landing (STOL) airstrip along with a passenger terminal building and maintenance hangar adjacent to Clear Lake City, Texas near the NASA Johnson Space Center.

The airline's initial route linked Clear Lake City (CLC) with Houston Intercontinental Airport (IAH) which opened in 1969.

The route system was later expanded to include a number of destinations in southeast and south Texas with flights to Houston Intercontinental.

The Short 330 was also utilized by Metro for flights between IAH and Beaumont/Port Arthur (BPT) where one was destroyed by a tornado in 1983 while sitting empty on the airport ramp (see Accidents and incidents below).

The addition of the 30 passenger Short 330 turboprops required Metro to make provisions for flight attendants and also resulted in the carrier joining the ranks of the regional airline industry via its use of larger aircraft.

These Twin Otter and Short 330 passenger services into DFW were flown by the Metroflight Airlines division which would eventually operate American Eagle flights.

Metro Airlines operated out of DFW via its wholly owned Metroflight division under the American Eagle brand beginning on November 1, 1984.

[5] Royale Airlines, a commuter/regional air carrier based in Louisiana, then assumed many of the routes that were previously operated by Metro into Houston.

These destinations were served with British Aerospace Jetstream 31 and/or Short 330 turboprops: These destinations were served with British Aerospace BAe Jetstream 31 turboprops and/or with de Havilland Canada DHC-8-100 Dash 8 turboprops: After the acquisition of the airlines "Sunaire" and the subsequent name change to "Aviation Associates," de Havilland Canada DHC-6 Twin Otter 250 & 300 turboprops served the following destinations: Many of these destinations were previously served by Metro Airlines on an independent basis prior to a marketing alliance with Eastern Airlines and were operated with Metro's very own DHC-6 Twin Otter aircraft: Metro was also operating Eastern Express service at this time from San Antonio International Airport (SAT) with service to Laredo, TX (LRD)[10] After the acquisition of the airline "Brockway Air" and its subsequent name change to "Metro Air Northeast," Beech-1900C and Saab-340A commuter aircraft served the following destinations upon TWA's TWExpress network: