KLIA aerotrain undergoes nightly checks to fix persistent system faults, but will it be enough?

KUALA LUMPUR – Malaysia Airports has imposed nightly shutdowns of the troubled Kuala Lumpur International Airport (KLIA) aerotrain for a month-long overhaul, the latest attempt to fix a rail system that has suffered repeated breakdowns since its relaunch in July.

The suspension, which began on Nov 15, forces passengers to use replacement buses between the main terminal and the international satellite building while engineers tackle what transport analysts said are deeper structural problems plaguing the RM456 million (S$143 million) upgrade.

Since the aerotrain’s

much-delayed return to service

on July 1, it has broken down several times – the first failure occurring just a day after reopening. The recurring disruptions have sparked public frustration and raised questions about procurement failures and declining airport standards.

Transport analysts warned that the problems go beyond simple technical glitches, pointing instead to fundamental integration failures between new trains and ageing infrastructure, worsened by contractor changes and years of delays.

“The reality is more complex,” said Mr Wan Agyl Wan Hassan, founder and chief executive of transport think-tank MY Mobility Vision.

“The failures stem from profound systems integration breakdowns, compounded by the termination and later reappointment of key players responsible for power and installation works.”

There were at least 19 incidents between the aerotrain’s relaunch on July 1 and Sept 30, Deputy Transport Minister Hasbi Habibollah told Parliament on Oct 13, citing signalling faults and “human-related incidents” such as passengers forcing open doors. However, only four were major disruptions.

The repeated failures could not have come at a more critical time for Malaysia, which aims to welcome 47 million international visitors in 2026. Any sustained disruption at KLIA, the country’s main international gateway, risks undermining that ambition.

On Nov 14, Malaysia Airports said the month-long plan, running until Dec 15 with the Ministry of Transport’s approval, involves nightly inspections, testing and rectification work from 9pm to 7am, with full bus services deployed to maintain connectivity during the suspension.

Malaysia Airports managing director Mohd Izani Ghani said the plan aims to systematically address root causes of past disruptions. He noted that the aerotrain has served about seven million passengers and completed over 53,000 return trips with 98.41 per cent operational service availability since resuming operations on July 1.

Mr Wan Agyl said a move to appoint an independent technical assessor signalled that internal checks were no longer enough to restore confidence. He also highlighted how an order for contractors to stay on site around the clock and bear rectification costs under the two-year defect liability period marks “a rare and unusually tough enforcement step” in Malaysian infrastructure management.

Fundamentally, he said, the repairs are trying to fix a system that was not properly tested before it started running, and underlying problems may emerge with time.

The core challenge is fitting brand new trains into the airport’s existing track structure – a delicate process that is far more difficult than building everything from scratch, especially when the system must keep operating around the clock.

A critical issue is ensuring that the new trains align perfectly with the old concrete and rail pathway, as even tiny mismatches can trigger breakdowns across the entire system.

Transport safety expert Law Teik Hua, head of the Road Safety Research Centre at Universiti Putra Malaysia, said the plan is “a step in the right direction”, but warned of operational risks.

He said KLIA’s temporary reliance on buses during the nightly shutdowns raises questions about whether the network has been properly stress-tested for peak-hour loads.

Beyond logistics, Dr Law added, the aerotrain’s reliability shapes the first impressions of millions of foreign visitors and influences whether transit passengers choose KLIA over Singapore’s Changi Airport or Bangkok’s Suvarnabhumi.

“In the scenario where Malaysia expects to strengthen its grip on transit and high-spending tourists... in terms of the experience and the flow connecting the international and domestic gates, (they have) got to be seamless,” he said.

KLIA handled 57.1 million passengers in 2024, including 41.9 million international travellers, according to aviation data firm Centre for Aviation.

The driverless aerotrain service was first suspended after an embarrassing February 2023 breakdown that forced 114 passengers to walk along the tracks mid-route, triggering widespread criticism over safety and contingency planning.

The long-delayed aerotrain replacement project had already missed three deadlines – July 2024, January 2025 and March 2025 – due to contractor termination and the appointment of new teams. It took more than two years to get the project ready for relaunch.

The project is now handled by French transport group Alstom, together with a joint venture between Malaysian companies IJM Construction and Pestech Technology.

KLIA’s main Terminal 1 houses immigration counters and handles most domestic flights, while international airlines operate from the satellite complex.

Budget airlines use Terminal 2, located less than 2km away.

Public relations consultant A. Abdullah, a frequent traveller, described her experience of using the shuttle bus in October, when the aerotrain was out of service, as highly inconvenient.

“It was difficult for passengers with luggage. We had to get off the plane and squeeze onto a bus,” she said. “There were so many people that we were packed in like sardines, and when it rained, we all got wet because the walk from the aircraft to the bus wasn’t covered. For the amount of money invested, the aerotrain really shouldn’t be breaking down like this.”

Correction note: This story has been updated to correct an erroneous headline that said the aerotrain was halted for one month. We are sorry for the error.