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Saturday, November 25, 2023

Pilots fret over long wait for instrument landing system at Subang airport


FMT:

Pilots fret over long wait for instrument landing system at Subang airport


They say the system, suspended in February last year, has not been replaced, forcing them to use obsolete non-directional beacons.



A Civil Aviation Authority of Malaysia spokesman says the time taken to replace the instrument landing system in Subang is reasonable, as it requires the complete removal of the old system before a new one is installed.


PETALING JAYA: Pilots using the Sultan Abdul Aziz Shah Airport runway have voiced concern over the lack of repairs to its instrument landing system (ILS) which failed more than a year ago, particularly the effect on aviation safety.

Given the unexpected and severe weather conditions of late, they said the ILS was vital as the current use of non-directional beacons (NDB) for landing was not only obsolete, but dangerous during inclement weather.

They also said that the situation had continued even though the Civil Aviation Authority of Malaysia (CAAM) announced the ILS’ suspension in February last year.

NDBs are ground-based radio transmitters used to aid and navigate aviation vessels during their approach, while the ILS is a highly directional guidance system with horizontal and vertical guidance components that provide precision landing down a glide path to the runway.

An experienced pilot, who flies into the Sultan Abdul Aziz Shah terminal four to five times a week, said several high-rise buildings that had come up near Denai Alam on the flight path had forced an increase in the minimum NDB approach height.

“The approach is based on an NDB that is subject to environmental interference, which often makes it unreliable. It is being phased out in much of the world and should always be the last choice.

“It is also subject to the effects of thunderstorms, as water droplets and ice crystals circulating within a storm cloud generate wideband noise that may affect accuracy. Lightning, too, could affect the bearings,” he told FMT.

Another experienced aviator said the increase in air traffic volume was making the situation more dangerous, noting that most VIP flights and private jets take off and land in Subang.

He said a lot of stress was put on pilots during NDB approaches as this involved mostly manual navigation.

“This is a serious safety issue for the ILS system to be non-functional for this long. If I am not mistaken, tenders were called more than a year ago for replacement. Pilots are wondering why it has not yet been rectified or replaced,” he said.

The senior commercial pilot agreed that NDBs were obsolete, with most parts of the world phasing them out as a safety measure.

New system operational in March

A CAAM spokesman said the time taken to replace the ILS in Subang was reasonable as it required the complete removal of the old system before a new one could be installed.

“The old system was installed in 2005 and, like any system, it has to be replaced after some time. The new one has been physically installed already, but we have to do various tests and fine-tuning before it is fully operational,” he told FMT.

He assured the industry and travellers that the new system was a much-improved version with new components and parts that would reduce technical faults.

“It is updated and should be operational by March next year.”

2 comments:

  1. One of Subang Airport's approaches , the one from the North East, is close to a range of hills.
    Depending on non-directional beacons, especially in bad visibility is an unnecessary risk.

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    Replies
    1. Batu Arang - it used to have a VOR (maybe still has), which is almost alike the ILS except it doesn't have a glide path; thus it's better than the NDB but not as good as the ILS

      But the S app definitely requires an ILS, especially as KL is known throughout the aviation world

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