The Civil Aviation Authority of the Philippines (CAAP) advised affected passengers on Thursday to coordinate with airlines ahead of the May 17 airspace shutdown.   The Philippine airspace will be closed for six hours on May 17 (12 midnight to 6 a.m.) to give way to maintenance activities on the country’s air traffic management system, the Manila International Airport Authority (MIAA) said on Tuesday.   Around 130 flights and 20,000 passengers are expected to be affected by the temporary closure.