IndiGo must replace all Pratt & Whitney (P&W) engines on its fleet of 97 twin-engine Airbus A320neo family aircraft with new P&W power units, the country's air safety watchdog said on Friday following recent inflight engine shutdowns.
The incidents have caused "serious concern" and the decision to order the engines be replaced was taken after "considerable deliberations," the Directorate General of Civil Aviation (DGCA) said in a statement.
"You will appreciate that four successive events have not happened ever before and therefore, we call for urgent and effective action. We regret the inconvenience but we need desperate measures to put things in order," the DGCA said.
"This situation cannot be allowed to go on indefinitely," it said, adding that the engines would need to be replaced by Jan. 31, 2020.
IndiGo is Airbus' biggest client for A320neo planes.
While the United Technologies' Pratt & Whitney engines are fuel efficient there have been issues since they entered into service in 2016, forcing the airline to ground its planes several times.
The groundings have cost IndiGo, which last month posted its biggest-ever quarterly loss after being forced to lease aircraft to replace planes grounded with engine issues.
On Monday the DGCA ordered IndiGo and domestic rival GoAir to modify 29 Airbus A320neo aircraft fitted with Pratt & Whitney engines within 15 days to avoid them being grounded.