P&W engine woes had forced grounding of 11 A320neos operated by IndiGo and three flown by GoAir.
"As of now, 11 of the 14 grounded aircraft have started flying after changing the engines," Minister of State for Civil Aviation Jayant Sinha said in a written reply in the Lok Sabha.
Following the grounding of the aircraft, 776 IndiGo flights were cancelled from March 13 till April 2. During the same period, GoAir had cancelled 336 flights, the minister said.
On March 12, the Directorate General of Civil Aviation (DGCA) had ordered grounding of 11 A320neo planes fitted with faulty P&W 1100 engines having serial number of 450 and beyond.
Out of the 11 planes, IndiGo and GoAir were operated eight and three, respectively.
In February, three IndiGo aircraft, with both faulty engines, were grounded. This followed the European Aviation Safety Agency (EASA) issuing an emergency airworthiness directive on February 9 after a few occurrences of aborted take-off and in-flight shut down on A320neo fleet worldwide.
But subsequently with three cases of in-flight shutdown, 11 other A320neo aircraft with engine glitches were grounded from March 12 keeping in mind the safety of aircraft operations, Sinha said.
He also said that any new type of aircraft before being imported is issued with 'letter of type acceptance' indicating the plane meets the type design requirements.
"A320neo aircraft were issued with type acceptance by the DGCA based on the type certificate issued by the EASA. These aircraft, installed with the PW 1100G-JM engines, were also issued with the type acceptance by the DGCA based on the type certificate issued by the Federal Aviation Administration (FAA)", the minister said.
On the inconvenience being faced by passengers because of the grounding of the aircraft, Mr Sinha said flight schedules have been altered to accommodate affected passengers and free cancellations and re-bookings are being made available.
Between March 13 and April 2, 776 out of 21,000 scheduled flights of IndiGo were cancelled while 336 out of 5,396 scheduled flights of GoAir remained out of service.
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