As a passenger on a plane, you can feel that moment when it lands, when the tyres touch the runway and the plane brakes to a stop.
For maintenance workers at Changi Airport, that moment is measured in tyre rubber that gets deposited on the pavement.
Every month during overnight runway closures, a team of workers scrapes the rubber off the two runways and repaints the landing zones with a special paint, which is treated to have more friction.
The New Paper followed the team on one of its recent monthly maintenance jobs, which runs from about midnight to 6am.
The team also ensures that the grass surrounding the runways is cut, the airside is cleaned, the airfield lighting is adequate and that runways and taxiways are free from foreign object debris and defects such as potholes.
It is all part of the behind-the-scenes work that keeps Changi Airport at the top of the airport listings. Changi was voted the world's best airport last year, the fourth time it has clinched the top prize since 2010.
The airport handles more than 50 million passengers each year and 6,500 flights come in every week.
The airfield lighting team and civil engineering team from the engineering and development group are the two teams responsible for runway maintenance.
Mr Andy Chin Yong Hwee, 33, airfield lighting system manager, said that as air traffic continues to grow in the Asia-Pacific region, there is a need to strike a time balance between flight operations and runway maintenance.
And this is quite challenging.