Weekly friction test to make Kolkata airport tarmac safer
Times of India | 22 March 2025
Kolkata: Flight safety at city airport received a boost on Friday with the introduction of a runway friction test vehicle.
Runway friction testing is a critical aspect of airport runway maintenance that ensures safe landings for aircraft. It involves measuring the friction between the aircraft's tyres and the runway surface to assess the braking performance and overall safety of the runway. Poor runway friction can lead to planes skidding, while braking or even overshooting the runway.
The typical landing speed of an Airbus A-320 or Boeing B-737 aircraft, which are popularly used by airlines for domestic flights, is 260 kmph. With a laden weight of around 64 tonnes, effective braking is crucial to bring the aircraft hurtling down the runway after touchdown to a halt. The friction of a runway decreases due to rubber deposits during the braking of landing planes.
To test the friction, a fire tender will first splash water on the runway. The indigenously manufactured testing vehicle will then speed down the wet runway at 120 kmph with sensors on its aircraft-type special tyres recording the surface friction and displaying it on a graph similar to an ECG. "If the friction on the runway is less, it is a threat to safe flight operations. We have to then use a rubber deposit removal machine to scrape the rubber off the runway and increase the friction so that it adheres to the DGCA guidelines," said an airport official.
Larger airports with more flight movements are required to do the friction test more regularly than smaller airports with fewer movements.
Kolkata airport was required to conduct friction tests once a month prior to Covid. The norms were made more stringent in 2022 with DGCA asking Kolkata airport to carry out tests every fortnight. Six months ago, the DGCA asked the airport to carry out the tests every week. But with only one friction testing vehicle available for 20 airports in Bengal, Bihar, Odisha, Jharkhand and Chhattisgarh, Kolkata airport could do the test only once a month. DGCA ticked it off for non-compliance. "Now that we have a dedicated friction testing vehicle in Kolkata, we can meet the enhanced safety standards," said an official.