Will Anak Krakatau keep disrupting Singapore-Jakarta flights? Analysts explain

Reopening airports may not end the disruption between Singapore and Jakarta. Further eruptions from Anak Krakatau, or a decision by airlines that conditions remain unsafe, could bring restrictions back even after flights resume.

Aviation analysts said the volcano’s continued activity alone does not determine whether aircraft can operate. The decisive factors are how much ash enters the air, how high the ash column rises, and where winds carry it. “An airport can be closed, then reassessed, reopened, monitored, and if conditions deteriorate, restrictions can be imposed again,” aviation analyst Polana Pramesti told The Straits Times.

“

An airport can be closed, then reassessed, reopened, monitored, and if conditions deteriorate, restrictions can be imposed again.

The operational effects can last beyond the closure itself. “Reopening an airport is not as easy as just restoring a schedule,” said Susanna Jenkins, an associate professor at Nanyang Technological University. Aircraft and crew can end up in the wrong places, crew duty-hour limits can take effect, and displaced passengers can compete for seats on already busy flights, she said.

“

Reopening an airport is not as easy as just restoring a schedule.

Singapore was the international route hit hardest by the initial closure, ahead of Hong Kong, Sydney, Seoul, Doha, Amsterdam and Kuala Lumpur. Indonesia’s aviation authorities said all 33 flights scheduled from Singapore to Jakarta on Sept. 6 were cancelled. Seven Indonesian airports, including Jakarta’s Soekarno-Hatta and Halim Perdanakusuma airports, were due to remain closed until 11:59 p.m. local time on Sept. 7. Atung Bungsu airport in South Sumatra resumed normal operations at 9 a.m.

The disruption had affected about 2,300 flights and 263,000 passengers by 9 a.m. on Sept. 7, according to Transport Minister Dudy Purwagandhi, up from about 1,700 flights and 170,000 passengers the previous day. Volcanic ash can melt inside jet engines and stick to critical components, while abrasive particles can damage aircraft surfaces and windscreens. The Indonesian meteorological agency detected ash at altitudes as high as 50,000 feet, or 15.2 kilometers.

“

Volume or concentration describes how great the hazard is. Altitude determines which flight levels are threatened. Wind describes where and how quickly the hazard moves.