Engine trouble has again come to haunt New Delhi-based low cost airline IndiGo. In a statement on Wednesday, the airline confirmed that “a few A 320 New Engine Options (NEOs) have been taken out of service proactively” while they await spare engines from Pratt and Whitney (PW).

IndiGo, however, did not specify the number of aircraft that were affected. “The release of additional spare engines has been initiated by PW so that all aircraft are expected to be back in service in the second half of August,” the airline said without specifying since when the aircraft have been out of service. Industry sources point out that at least 5 of the 173 Airbus in the IndiGo fleet have been affected. The 173 aircraft fleet includes 39 new generation A320 NEOs.

With each aircraft being capable of operating between four to six flights a day IndiGo may have been forced to cancel over 20 daily flights.

Earlier troubles

This is not the first time that IndiGo’s operations have been affected due to trouble with PW engines. In March, the Directorate-General of Civil Aviation grounded the airline’s 11 Airbus A-320 NEOs due to issues with the Pratt and Whitney engines that power these aircraft. DGCA had also grounded Go Air’s three Airbus A-320 NEOs at that time because of the same reason.