Budget carrier IndiGo has grounded another of its A320 neo aircraft, the airline confirmed on Tuesday, making it the sixth aircraft to be stopped from operations since July.
The aircraft has been grounded at the Indira Gandhi International (IGI) Airport in Delhi.
The airline maintained that the aircraft was grounded because it was undergoing a routine engine change.
"An IndiGo neo has been grounded and is undergoing a routine engine change. There is no impact on our flight operations," the airline said in a statement, but did not elaborate further.
According to sources, the plane was relatively new and was grounded Monday.
On July 25, the airline informed it grounded five A320 neo aircraft due to Pratt & Whitney engine issues, and that they were expected to be back in operations in the second half of August.
An IndiGo spokesperson had said that five A320 neos have been taken out of service pro-actively and await spare engines from Pratt & Whitney.
During the day, Pratt & Whitney also issued a statement saying "it is working closely with operators to address aircraft taken out of service as per established engine inspection plans".
"Engine removals are being planned and coordinated with the airlines as we continue to successfully retrofit the fleet with the latest configuration engines. Some aircraft will be out of service temporarily as they perform these removals. Spare engines are now becoming available, with the objective to support aircraft availability in August and onward. We will continue to work with each airline while we incorporate enhancements to their fleet," Pratt & Whitney said in the statement.
P&W engine woes had forced the airline to ground some of the A320 neo aircraft on earlier occasions also.
At present, IndiGo has a fleet of more than 170 aircraft, including 40 A320 neo planes.
During February and March this year, 14 planes -- 11 of IndiGo and three of GoAir -- were taken out of operations due to P&W engine issues on the directions of the aviation regulator after a series of mid-air shut downs were reported by the two carriers.
The grounding of the IndiGo flights during this period had hit 1.08 lakh passengers.
In the 2017 June quarter, IndiGo grounded nine A320 neo planes due to engine issues. The grounding had also resulted in the airline cancelling 84 flights on a particular day last year.