New Delhi: India’s aviation regulator, the Directorate General of Civil Aviation (DGCA), has revised its operational guidelines for both scheduled and non-scheduled operators, directing pilots to prioritise safety over “schedule adherence” during adverse weather conditions.

The move comes following recent helicopter accidents in the Kedarnath region and an IndiGo flight en route to Srinagar encountering severe turbulence last month.

Pilots encouraged to divert flights if required

Issuing a new operations circular, the DGCA has stated, “Captains are encouraged to initiate diversions or air-turn-backs, as required by prevailing conditions.” The circular outlines that diversion, return or rerouting decisions should be taken by flight crew in cases of severe turbulence, windshear, icing, obstructive thunderstorms or sudden drops in visibility.

Highlighting the increasing operational unpredictability linked to climate change, the regulator has asked crew to maintain heightened vigilance, “with an emphasis on safety taking precedence over schedule adherence”.

Enhanced focus on night operations, communication, and scenario training

To address risks during night flights in rain or on wet runways, pilots have been instructed to cross-check visual cues with instruments to prevent misjudgements caused by visual illusions. Operators and pilots have also been urged to adopt a conservative approach to decision-making and plan for weather avoidance.

The circular advises, “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 DGCA also underlined the need for improved communication with passengers, cabin crew, and Air Traffic Control (ATC) during turbulence. “This includes timely briefings, advance passenger announcements, and turbulence reporting to ATC to support better coordination and situational awareness,” it said.

Ice Crystal Icing addressed for the first time

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

Additionally, operators have been encouraged to implement scenario-based training related to decision-making in adverse weather and the application of Threat and Error Management (TEM) principles.

“The revised circular remains applicable to all scheduled and non-scheduled operators, as well as all flight crew operating during the pre-monsoon, monsoon, adverse weather and periods of turbulence,” the DGCA stated.

What is Ice Crystal Icing and why is it dangerous for flights?

Ice Crystal Icing (ICI) is a high-altitude threat that forms invisibly in clear air, often above 33,000 feet, typically over or near large thunderstorm systems. Unlike traditional icing that sticks to the aircraft’s surface, ICI involves tiny ice crystals—smaller than flour grains—getting sucked into jet engines. These crystals melt on warm surfaces inside the engine core, creating a film that causes more ice to stick, potentially leading to engine flameouts, surges, or even permanent damage.

What makes ICI especially dangerous is its stealth: it often doesn’t show on radar or trigger cockpit ice detectors. Pilots may be unaware of the risk until engine vibrations or power loss occur. The only defence is awareness—avoiding convective cloud tops and exiting weather systems laterally.