IndiGo Airlines (6E, Delhi Int'l) has advised its pilots to operate at a maximum altitude of 30,000 feet when flying its A320neos due to concerns over the aircraft's Pratt & Whitney engines, reports Live Mint. The news site has seen a copy of a note from Ashim Mittra, IndiGo's Vice President of Flight Operations, which further advises pilots to carry additional fuel to accommodate the lower altitude flights.

As previously reported, the PW1100G geared turbofans have presented several issues, namely combustion chamber issues and a problem with the one of the bearings. The Indian aviation regulator Directorate General of Civil Aviation (DGCA) earlier this year ordered examinations of the engines, which are also used by GoAir (G8, Mumbai Int'l). The DGCA has set a borescope test for the powerplants after 1000 flight hours instead of the usual 1500. Commenting at that time, IndiGo spokesman Ajay Jasra said that the airline was working the engine manufacturer to address the issues.

Pratt & Whitney has been working with airlines to address the issues as they arise. Bloomberg reports that the manufacturer will reserve around 13% of its engines to deploy as replacements for faulty units, with more than 50 engines this year to be used as spares.

IndiGo, which operates to destinations throughout India as well as to Bangkok Suvarnabhumi, Dubai Int'l, Kathmandu, Muscat, Sharjah, and Singapore Changi, has more than 400 A320neos currently on order with Airbus (AIB, Toulouse Blagnac).