Airbus has informed IndiGo that all A320neo deliveries are on hold until further notice following the discovery of a new issue with the Pratt & Whitney PW1100G engine, the carrier's parent company InterGlobe Aviation has disclosed.

This comes after the European Aviation Safety Agency stated that several A320neo-family aircraft had experienced engines failures in flight or during take-off, and that the problem applied to a series of recently delivered geared turbofans starting with the serial number P770450.

P&W added that preliminary findings indicated that the problem was with the knife edge seal on the modified aft hub of the high-pressure compressor.

"Product safety boards of P&W and Airbus, post evaluating the PW1100G-JM engine issue, have decided that all Neo deliveries are on hold 'til further notice," states InterGlobe in a filing with the Indian stock exchange.

InterGlobe says low-cost carrier IndiGo has since grounded three of its aircraft "in the interim", and that the issue impacts "a limited sub-population" of engines.

The company adds that IndiGo will meanwhile continue to add more A320ceos and ATR turboprops to its fleet.

It is still not immediately clear if the recent aft modification is related to the geared turbofan family's other known durability issues. Those include an air seal in the No 3 bearing and a compressor liner that wears out years faster than the design requirement. P&W had resolved both of those problems in the fourth quarter last year, parent company United Technologies reported last month.

Flight Fleets Analyzer shows that IndiGo operates a fleet of 157 aircraft, comprising 122 A320ceos, 32 A320neos and three ATR 72-600s. While it does not have any outstanding deliveries for A320ceos, it has 398 A320neo-family aircraft and 47 ATR 72-600s on order.

Source: Cirium Dashboard