New Delhi:

The Directorate General of Civial Aviation (DGCA), the country's aviation regulator, has directed Indian airlines to inspect Boeing B737 aircraft in their fleet after the US aviation regulator Federal Aviation Administration (FAA) issued an emergency directive in this matter on Friday.

Three Indian airlines — SpiceJet, Air India Express and Vistara — have B737 aircraft in their fleet.

The emergency directive was "prompted by four single-engine shutdowns" that happened due to compromised air check valves in the engines of the certain B737 aircraft, said the FAA in its emergency directive.

The FAA asked the airlines to inspect their B737 aircraft that had not flown for seven days or more and the ones that had operated not more than 10 flights after return to service.A senior DGCA official said the Indian regulator had asked Indian carriers SpiceJet, Vistara and Air India Express to inspect their B737 aircraft as directed by the FAA.

Another DGCA official said inspection of some of the Indian aircraft had already been done by their owner airlines.

Boeing said in a statement: "Out of an abundance of caution, Boeing has advised operators of 737 Classic airplanes (series -300 to -500) and Next-Generation 737s (series -600 to -900) to inspect an engine valve for corrosion. With airplanes being stored or used infrequently due to lower demand during the COVID-19 pandemic, the valve can be more susceptible to corrosion."

Boeing is providing inspection and replacement information to fleet owners if they find an issue, it added.

SpiceJet spokesperson said the FAA airworthiness directive (AD) applied to a small number of 737s in its fleet that had not yet completed 10 cycles on return of aircraft to service. "They are being inspected. The majority of our planes have completed 10 cycles already and are not affected by this AD," the SpiceJet spokesperson added.

On this matter, Vistara spokesperson said, "Vistara is in compliance of the directive. The inspection of the engines of all six of our B737 aircraft has already been completed.