SINGAPORE — There are inaccuracies in Malaysia's understanding of how the Instrument Landing System (ILS) — which is designed to safely guide planes approaching and landing on a runway — works, Transport Minister Khaw Boon Wan said on Wednesday (Dec 12).

Mr Khaw pointed out that if there are technical concerns, he is confident that a “mutually technically satisfactory solution can be found”, but he added that Malaysia appears to be using a “technical excuse” to demand a change in airspace management.

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He was responding to Malaysia's Transport Minister Anthony Loke's Facebook post put up late Tuesday evening. The post contained a video that is more than a minute long, in which Mr Loke said that the flight path used by the ILS will encroach into Malaysian airspace.

Singapore plans to start using the system for Seletar Airport from Jan 3 next year. That means planes from that airport will have to fly over the Johor Baru town of Pasir Gudang, Mr Loke noted.

The video repeated Malaysia’s claims that the ILS will affect the town’s development as height restrictions on buildings and other structures will be imposed.

The video showed that there is a safety height buffer of between 54m and 145m from the flight paths within a distance of 3km and 6km from Seletar Airport. This means that a crane with a height of 103m could end up being in the way of any descending plane.

“We can’t even build tall buildings in Pasir Gudang if we allow that flight path,” Mr Loke said in the video. “Our position is very clear. We are not against Seletar, but as far as the descending flight path is concerned, it cannot be over Pasir Gudang.”

The video also showed that previously, pilots flying in and out of Seletar Airport can manoeuvre around any obstacles.

Mr Loke said: “We urge Singapore to withdraw the ILS announcement and to amend the flight path as per our request.”

'THAT IS NOT HOW ILS WORKS'

Speaking to reporters at the Ministry of Transport located at PSA Building, Mr Khaw said that the video “contains a few inaccuracies”.

One example was Malaysia’s point that, unlike a manual system, the ILS could pose a safety risk.

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“But that’s not how ILS works. ILS is like an auto-pilot in an aircraft, it's a tool for the pilot. The pilot can always have a manual intervention if security concerns require it,” Mr Khaw said. “So, auto-pilot doesn’t mean the pilot doesn’t have control. The pilot retains full control throughout the flight.”

Another inaccuracy relates to the safety height buffer. Under the ILS procedures, flights will use a glide path when they descend. Below this glide path is the Obstacle Assessment Surface, or a safety height buffer, that extends from on-the-ground structures to the glide path. Structures cannot penetrate this buffer and the height restrictions vary along the path of descent.

The safety height buffer at the 3km mark is 93.8m, and at the 6km mark, it is 193.1m. This means that the height of structures cannot exceed those figures. Right now, the tallest structure in Pasir Gudang is 105m and is located 3.6km from Seletar Airport. So, it falls under the 193.1m height restriction.

Contrary to what the video stated, developments in Pasir Gudang have not been constrained by the existing flight path to Seletar Airport, which has been used for decades. Likewise, there will be no impact on port and shipping activities. There has been a standard procedure for flights to be held back while tall vessels cross the Straits of Johor.

Mr Khaw added that Malaysia may have another intention in wanting Singapore to remove this system: To change the airspace arrangement which, he said, has “worked very well, benefiting stakeholders in this region”.

“So I’m truly baffled. I wonder why.”

Singapore has been managing the airspace over Southern Johor since 1974, when both nations signed a bilateral agreement to enforce the arrangement.

This was approved by the International Civil Aviation Organisation, following consultation with Malaysia and other regional countries.

Under the bilateral agreement, the provision of air traffic services in the airspace over Southern Johor was delegated to Singapore, the MOT previously said.

On the other hand, Mr Loke said earlier this month that the Malaysian government will start the “first phase” of reclaiming its airspace at the end of next year. The next stage will begin in 2023, he added.

Mr Khaw pointed out that the transport ministries in both countries have worked “very well together” for many years on bilateral issues and on international platforms.

“We have achieved so much together. And then now, out of the blue in October, suddenly they started a row in air, in water,” Mr Khaw said, referring also to the maritime dispute which happened after Malaysia extended its Johor Baru port limits on Oct 25, and its vessels started intruding into Singapore’s territorial waters.

“What’s next? Land transport, too? I wonder why,” Mr Khaw asked.

On whether Singapore is willing to reconsider retracting the ILS, Mr Khaw repeated his point that “if it were a technical concern, with goodwill, I’m quite sure a technical solution that satisfies both sides can be found”.

“But if it is not, it is just a technical excuse to trigger an unfriendly act, then I think it's a different story.”

During his first official state visit to Singapore since the Pakatan Harapan government took power in May, Malaysia’s Prime Minister Mahathir Mohamad had described both countries as  “twins”, although one is "older and bigger" than the other.

On this, Mr Khaw said that it was a “good illustration”, but noted: “As twins, you ought to embrace each other and help each other grow. And help each other succeed and celebrate each other's achievements. Then I think it is so much better.”