New Delhi, Mar 13: In an unprecedented regulation, India's Directorate General of Civil Aviation (DGCA) cracked whip on budget carriers IndiGo and GoAir, which were using the A320neo planes powered by the latest Pratt & Whitney engines.

As a result of the DGCA order, eight aircrafts of Indigo, the nation's largest carrier, along with three flights of GoAir were grounded.

The impact on aviation came to the fore on Tuesday as IndiGo was forced to cancel 47 flights, while, 18 were cancelled by GoAir.

Here's Why IndiGo and GoAir A320neo Planes Are Grounded

The DGCA cracked the whip late on Monday, after a Lucknow-bound IndiGo flight returned 40 minutes after departing from Ahmedabad airport due to single engine failure.

The flight was equipped with a pair of P&W engines, one out of which stopped functioning.

This was the third such incident in the past one week. Citing the threat posed to passenger safety, the the flight regulator ordered IndiGo and GoAir to ground all its flights powered with latest model of P&W engines (of ESN 450 and above).

What is the glitch with Pratt & Whitney engines?

Pratt engines were considered to be the most reliable world over -- till it launched the geared turbofan model last year.

The symptom of defect comes to the fore after the engine seal begins vibrating while the flight is in operation.

The engine manufacturing firm, a subsidiary of United Technologies Corp, acknowledged the glitch last year, assuring the carriers that at least one seal of the pair of new engines stalled in planes will be replaced by the company.

The defected seal would be replaced by the older seal, the one installed in the erstwhile version of the P&W engines.

In an emailed statement to media groups after the DGCA's red-flag, Pratt & Whitney said the defected components will be replaced totally by June this year.

European regulator backs P&W

The European Aviation Safety Agency, the primary regulator for Airbus planes, marked its disagreement towards the "unilateral action" taken by India against carriers flying with the Pratt engines.

The EASA claims no threat to carriers using the latest P&W engines, provided they are not used for oversea routes as no airports would be available for emergency landings in worst case scenario.

IndiGo shares dip

Market was quick to react to the regulation of DGCA, with the shares of IndiGo plunging by 3 per cent on Tuesday.

IndiGo, which had grabbed nearly 40 per cent of India's aviation market share, had grounded seven planes in July last year due to the defective P&W engines. In February, it had similarly laid off three aircrafts. Post the DGCA's order, seven more were taken off the active fleet.

(The above story first appeared on LatestLY on Mar 13, 2018 06:58 PM IST. For more news and updates on politics, world, sports, entertainment and lifestyle, log on to our website latestly.com).