InterGlobe Aviation, the company which owns and operates IndiGo Airlines, on Wednesday said it had grounded five Airbus A320neo aircraft at New Delhi’s Indira Gandhi International Airport citing trouble with the engine, Reuters reported. The engines were manufactured by United Technologies’ Pratt & Whitney.

The airline’s operator said the aircraft are scheduled to be back in service by the second half of August. Following the company’s statement, InterGlobe shares dropped by 3.2%, its record low in 14 months. It shares closed at a decline of 2.28%.

In February and March, the aviation regulator directed IndiGo to ground eight of its flights due to safety concerns. The company has had several changes recently – on April 27, the company told the stock exchanges that its president and director, Aditya Ghosh, was stepping down. Several other changes have been made in the top management as well.