It’s the invisible enemy: something all pilots dread as they land at Asia’s tropical island resorts.
Wind shear – or the sudden change in wind speed and direction – is particularly hazardous at landing, but some of the region’s best known holiday spots in Indonesia, Thailand, Malaysia and the Philippines do not have detection systems on the ground to warn pilots, according to airport officials.
This phenomenon of turbulent winds is common in equatorial Southeast Asia. A Lion Air pilot of a new Boeing Co 737 passenger jet that crashed off Bali only last month told investigators how his plane was “dragged down” by wind into the sea just short of the runway. Remarkably, no-one died.
“There are quite violent thunderstorms that are huge. You can easily exceed the capability of the airplane in severe wind shear,” said Richard Woodward, a Qantas Airways Ltd captain who flies A380s.
“The beauty of having a ground-based system is they can tell in advance if wind shear is present,” said Woodward, who has flown in the region for more than 30 years.
A ground warning system, which costs about $1 million, can help spot dangerous winds in the plane’s flight path, giving pilots more time to avoid them.
But even as revenues rise and building work on glitzy new terminals charges ahead, officials say the airports at Bali, Koh Samui, Langkawi and Cebu do not have the on-ground wind shear detection equipment.
As the middle class grows in Southeast Asia, plane travel increases, with low-cost carriers such as Indonesia’s privately owned Lion Air and Malaysia’s AirAsia Bhd winning 52 per cent of the region’s market share. That is almost double the level of five years ago.
But behind the facades of the new terminal buildings is a chronic shortage of weather detectors, runways, air traffic control staff and pilots to cope with the burgeoning demand for flying in a region home to 600 million people.
None of the airports in Indonesia or the Philippines has low-level wind shear alert systems (LLWAS) on the ground, airport and government officials say.
The Jakarta and Bali airports might get LLWAS next year, according to the Indonesian state weather agency, which is responsible for funding such systems.
“LLWAS is not yet in place in Indonesia, maybe because of budgets,” said Syamsul Huda, director for aviation and meteorology at the agency. “I feel it is more safe with the system.”
The Malaysian island of Langkawi has an Instrument Landing System (ILS), which helps guide pilots when they cannot see the runway, but does not have a wind shear detection system.
The Thai island of Koh Samui, famed for its reefs and beaches, lacks both an ILS and wind shear detection systems. The country’s top beach resort Phuket has both, and nearby Krabi recently installed a wind shear alarm.
The state-owned airport in Bali has seen its number of passengers grow by two-thirds in the past five years to 14 million people annually, and expects over 20 million in coming years.