International Airports:
Airports with border control facility and other services used for International flights

Principal Airports:
Airports used for domestic scheduled flights (or domestic airports served by carriers certified under AO No. 121)

.......... Class 1: Airports used for Jet services (Jet aircraft including B737, A320, DC9 or greater, which has equal to or more than 100-seat capacity)

.......... Class 2: Airports used for Prop services (Prop aircraft or jet aircraft smaller than those indicated in Class 1, which has equal to or more than 19-seat capacity)

.......... Class 3: Community Airports used for General Aviation and Prop services, (Prop aircraft which has less than 19 seat capacity)

In 1986, there were 230 airports in the Philippines. In 2006, 172 remained.
Source:Philippine Statistical Yearbook, 2006