DGCA revises guidelines for flight ops in adverse weather, emphasising safety over 'schedule adherence'

Issuing an updated operations circular to scheduled and non-scheduled operators, the regulator also said pilots should cross-check visual cues with instruments to ensure accurate approach and landing assessments to deal with visual illusions that may occur during night operations in rain or on wet runways.

New Delhi: With monsoon raising operational challenges to airlines, the Directorate General of Civil Aviation (DGCA) has revised guidelines, which insists that the pilots “should not proceed to the planned destination in uncertain conditions” and options like entering a holding pattern, diverting, or returning should be exercised “without hesitation when warranted”.

Heavy rainfall, enroute icing, moving clouds, severe turbulence, strong gusty winds, severe thunderstorms, and lightning inside the clouds are some of the “challenging scenarios” that a pilot has to contend with while flying during a monsoon.

A DGCA statement said the revised Operations Circular sets forth conditions under which flight crew are expected to consider diversion, return, or rerouting due to adverse weather. Operators and pilots have been advised to “adopt a conservative approach” to decision-making, emphasising that early action enhances flight safety, it said.

The circular also puts emphasis on timely communication with passengers, cabin crew, and Air Traffic Control (ATC) during adverse weather and turbulence. Captains are encouraged to initiate diversions or air-turn-backs, as required by prevailing conditions, the statement said.

“Pilots are encouraged to plan deviations early and maintain a minimum 20 NM (Nautical Miles) upwind distance from convective activity...Flying beneath thunderstorm clouds is discouraged due to the elevated risk of windshear, lightning, and hail,” the statement said.

Pilots should announce expected turbulence in advance, using a clear and calm tone to passengers. During turbulence, remind passengers to remain seated with seat belts fastened and updates should be given when conditions improve. The ATC should be informed about significant turbulence, sharing position and severity besides requesting early altitude and/or lateral deviations, if needed.

The circular also highlights the growing impact of climate change on operational unpredictability. Crew is advised to maintain heightened vigilance, with an emphasis on safety taking precedence over schedule adherence.

The circular also warned about visual illusions during night operations in rain or on wet runways, which makes it difficult to judge distance and altitude accurately.

During rains at night, the circular said, the lights of the Approach Light System can appear brighter than they actually are, which could make pilot mistakenly believe it is closer to the runway and land short of the threshold. A wet runway, which reflects very little light, increases the risk of a late flare and a hard landing.

For the first time, the statement said, the DGCA has addressed Ice Crystal Icing, a phenomenon associated with convective weather systems. “Pilots are advised to navigate around such areas laterally rather than climbing or descending through them in line with global best practices,” it added.