These groundings are due to combustor distress found during routine scheduled boroscopic inspection. These are all Block B combustors, it added.
This refers to inspection done using a boroscope -- an optical device that is used for inspecting parts that are generally inaccessible.
Taking note of the grounding, Prabhu has sought a detailed report on the matter from the DGCA.
Security of the passengers is of paramount importance and at no cost the security should be compromised, he said in the statement.
As per procedure, when combustor distress is found beyond laid down limits, the aircraft is removed from service for engine replacement.
According to the watchdog, A320 neos inducted after March 2018 are coming with P&W engines fitted with Block C combustors which have better life. Engines coming from shop are also fitted with Block C combustors, it added.
IndiGo and GoAir have been grappling with P&W engine problems persisting for many months.
"The manufacturers have taken measures to address significant problems of engines related to combustion chambers distress and No 3 bearing issues by replacing Block B combustion chambers with Block C and providing dry face bearing seals.
"These measures have significantly reduced the engine problems," the DGCA said.
In the case of neo engine issue, the regulator said P&W has introduced modifications.
"Further, the DGCA introduced additional measures for inspection of combustion chamber at reduced interval compared to manufacturer guidelines for boroscopic inspection of combustion chambers and removing engines as a preventive measures," it added.
About the grounding, DGCA chief B S Bhullar told PTI that these are "preventive removals due to our stringent check parameters put in place last year due to problems encountered that time".
Airlines continue to take up the issues with the engine manufacturer for quick replacement of removed engines with modified versions, he said.
Last month, IndiGo and GoAir carried out "visual inspections" of a total of 50 P&W engines powering their A320 neo aircraft but no abnormalities were detected, an official had said.
The visual inspections were done after US regulator FAA (Federal Aviation Administration) issued an airworthiness directive on June 26 to check for possible engine fan hub damage of certain P&W engines.
The regulator also made it clear that issues of A320 neo engines and that of battery faced by B787 planes are two different scenarios.
"In B787, battery exploded in the cabin making it a safety issue followed by worldwide grounding till modification was brought out by Boeing and approved by FAA and implemented by operators," it said.
Back in 2013, six Boeing 787 aircraft were grounded due to battery issues.
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