Aviation safety regulator DGCA on Monday came out with revised Flight Duty Time Limitations (FDTL) norms for flight crew, entailing increased weekly rest periods to 48 hours, extension of night hours, and limiting the number of night landings to only two as against six earlier.

These regulations have been instrumental in managing fatigue-related aviation safety risks for more than a decade now, an official statement said.

Airlines are required to comply with the revised norms latest by June 1, it said.

With a view to address and mitigate concerns on pilot fatigue through a data-driven approach, Directorate General of Civil Aviation (DGCA) collected and analysed extensive numbers of pilot rosters, along with pilot fatigue reports submitted by airline operators, it said.

Based on the study and analysis, some of the key areas inducing fatigue, such as maximum flight duty period, night duty, weekly rest period, flight duty period extension, among others, were identified, it said.

The revised FDTL regulations have been formulated after extensive data analysis and feedback from various stakeholders, including airline operators, pilot associations and individuals, as per the statement.

It also said the best practices in the world -- FAA in the US, and EASA in the European Union -- have also been taken into consideration in amending the regulations, while keeping in mind the specific operating environment in India.

The revised regulations mandate increased weekly rest periods from 36 hours to 48 hours for flight crew, thus ensuring sufficient time for recovery from cumulative fatigue, it said.

Moreover, the definition of night has been amended and it now covers the period of 0000-0600 hours in the revised regulations vis-a-vis the period of 0000-0500 hours under the previous regulations.

This enhancement of one hour during the early morning will ensure adequate rest and also align the night duty period, which encompasses Window of Circadian Low (WOCL) from 0200-0600 hours, the time during which the circadian body clock cycle is at its lowest in terms of alertness, the statement said.

Also, the revised regulations have taken into consideration different types of operations across time zones, the statement said, adding that the maximum flight time and maximum flight duty period for flight operations encroaching night have been restricted to eight hours' flight time and 10 hours flight duty period, respectively.

The number of landings has been limited to only two as against the maximum permissible six under previous regulations during night operations, thus enhancing flight safety, it added.

Except for the headline, this story has not been edited by The Telegraph Online staff and has been published from a syndicated feed.