New Delhi: In a series of steps to curb noise pollution at the IGI airport here, the National Green Tribunal (NGT) on Friday directed the Union civil aviation ministry to ensure ‘judgement based’ use of reverse thrust by aircraft, building of sound barriers and erection of a green belt around the airport’s boundary wall.

Thrust reversal, also called reverse thrust, is temporary diversion of an aircraft engine’s exhaust so that it is directed forward, rather than backwards, in order to reduce speed and noise.

A bench headed by NGT chairperson justice Swatanter Kumar passed a slew of directions to minimise the noise generated during take-offs and landings of aircraft.

“The respondents may issue an advisory to all airlines whose planes land at the IGI and domestic airport for ‘judgement based’ use of reverse thrust in view of weather, length of runway, wind and other circumstances to reduce the noise pollution level, particularly at the time of landing of aircraft,” it ordered.

The NGT’s judgement came on a batch of pleas filed by residents of Vasant Kunj, Bijwasan and Indian Spinal Injuries Centre, a super-specialty hospitaltion.