DGCA Flight Duty Relaxation Sparks Pilot Safety Alarm

'Extending 'flight duty period' and 'flight time' limits for minimum crew complement operations increases exposure to fatigue-related performance degradation.'

A pilots' union has written to the Directorate General of Civil Aviation (DGCA) warning that the temporary relaxation in flight duty limits granted to Air India could compromise flight safety by increasing fatigue risks for pilots operating long international flights.

The Federation of Indian Pilots (FIP) wrote the letter days after the regulator allowed temporary extensions in Flight Duty Time Limitations (FDTL) for certain Air India international flights that are taking longer routes following the closure of Iranian and Iraqi airspace amid the ongoing West Asia conflict.

Pilot Union Flags Fatigue Risk

In the letter, the pilots' body said that any relaxation of fatigue limits must be approached cautiously, particularly for flights operated by a minimum crew of two pilots without 'augmentation'.

Generally, long-duration pilots have an augmented cockpit composition of three pilots, so that each one can take adequate rest mid-air.

'Extending 'flight duty period' and 'flight time' limits for minimum crew complement operations increases exposure to fatigue-related performance degradation,' the union said, adding that research cited in international aviation guidance shows pilot alertness and cognitive performance decline significantly when duty durations approach or exceed 13 hours.

Flight duty period refers to the total time a pilot remains on duty, including pre-flight preparation, the flight itself and post-flight procedures.

Flight time is the period from when an aircraft begins moving for take-off until it comes to a stop after landing.

The union said the fresh relaxation granted by the DGCA allows an additional 1 hour 30 minutes of flight time and 1 hour 45 minutes of duty period beyond the limits prescribed under current regulations, calling it 'a very serious dispensation granted by DGCA without any scientific study'.

DGCA Extends Flight Duty Limits

FIP also cautioned that risks increase when extended duty periods overlap the Window of Circadian Low (WOCL)--the time during the body's natural sleep cycle (typically between about 2 am and 6 am)-- when alertness and performance decline.

'During such periods, flight crew may still be required to manage weather deviations, fuel planning due to rerouting, and precision approaches into congested airspace,' it said.

The pilots' body further said the variation appears to place no clear limit on the number of sectors or landings that may occur within the extended duty period.

Circadian Low Raises Safety Concerns

A sector refers to a single flight segment between two airports.

The union said the absence of limits could lead to situations where pilots perform more than one landing at the end of an already long duty period.

'This may lead to scenarios where pilots perform two landings toward the end of an already prolonged duty period,' the letter said, adding that fatigue during approach and landing -- among the highest workload phases of flight -- could increase operational risk.

The union also pointed to longer block times on some routes due to rerouting, citing the Delhi-Amsterdam sector where pilots are logging about 11 hours and 44 minutes of flight time.

Block time refers to the total time between an aircraft pushing back from the departure gate and arriving at the destination gate.

'At present, several of these sectors are operated using augmented crew complement. However, the present deviation would permit operation with two-pilot crews under extended duty provisions,' it said, warning that this would increase fatigue exposure and reduce operational safety margins.

Longer Routes Increase Pilot Workload

FIP also flagged aircraft-specific factors on the Boeing 787 aircraft fleet used on many long-haul Air India routes.

It said seat-position restrictions introduced after a decompression-related safety directive limit the ability of pilots to recline or move the seat aft during flight, reducing opportunities for meaningful rest during cruise phases.

The pilots' body urged the regulator to review the FDTL exemption and consider mitigation measures such as crew augmentation, effective fatigue monitoring and consultation with pilot representatives.

'Effective fatigue management remains one of the fundamental pillars of aviation safety, and any relaxation of duty limits must be carefully evaluated to ensure operational challenges are addressed without compromising safety margins or crew wellbeing,' the letter said.

Feature Presentation: Ashish Narsale/Rediff