to the eastern side of runway 20. A new access road was also constructed, complementing its facility. Commercial operation by Philippine Airlines commenced in 1952 using a Douglas DC-3 aircraft for routes to and from Cebu City and Zamboanga City. Concreting and expansion of the runway was made in 1974 when a new taxiway and apron was built. A new terminal building was constructed in 1980, relocating the old terminal to where it stands to this day. A bigger parking area and new access road was opened with the new terminal. A control tower was added in 1991, and new runway lights were installed in 2004. The airport's strategic location during World War II and the liberation of Zamboanga and Mindanao by American and Philippine Commonwealth Forces in 1945 prompted the national government to develop the field as an alternate to Zamboanga International Airport principally for national security reasons arising from natural and man-made emergencies. This was made apparent during the tumultuous period of the Muslim Rebellion in the early 1970s. Its infrastructure at that time was testament to its strategic importance. Commercial traffic The late 1980s saw a dramatic upsurge in foreign tourist arrival. Aerolift Philippines launched flights to Manila using a Beechcraft 1900-C aircraft in 1987. The airport's commercial viability for growth was established as more flights were mounted by Philippine Airlines prompting the national government to introduce further development. The city government of Dipolog incorporated its growth potential in their development strategy plan. In 1992, after extending its runway by and constructing a control tower, Dipolog Airport officially welcomed its first mid-size passenger jet, a Philippine Airlines Boeing 737-300. The same year, daily flights to Dumaguete were introduced by PAL using Short 360 aircraft but were dropped one year later. In 2002, at least 25% of the passenger traffic bound for Dipolog Airport was composed of foreign tourists. In July 2006, Cebu Pacific launched non-stop service to Manila using an Airbus A319 with a seating capacity of 150 passengers. In December 2006, it registered a maximum traffic of 330 daily passengers on several occasions based on the aircraft's available capacity serving the route with Philippine Airlines using the much bigger Boeing 737-400 with a seating capacity of 180 passengers. The airport was expected to handle more than 150,000 passengers per year by 2009 or an average of 415 daily passengers, which is equivalent to three narrow-body aircraft