The grounded planes of budget airlines IndiGo and GoAir will start flying again by the end of April, said the president of the engine-maker Pratt & Whitney on Sunday, according to IANS. The Directorate of Civil Aviation on March 12 grounded 11 A320neo planes that ran on faulty Pratt & Whitney engines.

“We’re disappointed with the [DGCA’s] decision, but I can tell you that by the end of April, that fleet will be back up in the air flying in India,” said Robert F Leduc.

The faulty engines have a seal that causes vibrations and leads to in-service shutdowns, reported NDTV quoting the DGCA. Leduc said they will retrofit and rework the engines. “Admittedly, the timing is a little bit skewed because of the first quarter and having to rework engines, but we will catch that up primarily by the end of the third quarter,” he added. “The fleet will be completely back in the sky by the end of April.”

The DGCA’s decision came hours after an A320neo aircraft of IndiGo suffered an engine failure mid-air and was forced to make an emergency landing at the Ahmedabad airport. The aviation authority has asked both IndiGo and GoAir not to refit these engines with spare parts in their inventory.

After the DGCA’s orders, IndiGo and GoAir have cancelled more than 600 flights scheduled till March-end. The cancellations are likely to affect an estimated 1 lakh passengers if the passenger load factor of both these airlines in January are taken into account. If the grounded flights are not back in service, the impact of the cancellations is likely to be worse in April with the start of the summer schedule.