The Directorate General of Civil Aviation (DGCA) will take the harshest action with respect to engine issues in A320neos of IndiGo and GoAir if the need arises but for now, the problem is being contained, the regulator said in a statement today.

About 40 percent of the domestic seat capacity of India is powered by Neo engines.

Today, the regulator had summoned officials of the two airlines today to discuss the airlines’ long-running troubles with the Pratt & Whitney engines.

"As there has not been any reported case of an accident in any part of the world, where these engines are in operation, will it be prudent?” the regulator reasoned and added that knee-jerk reaction to completely shut Neo operations will have serious consequences.

“It is true that there have been cases of air turn back, in-flight shutdown or Engine vibrations beyond the prescribed limits, but with strong mitigation measures in place and strict adherence to the standard operating procedure by the airlines, the problem is being contained. Whenever there is a problem with the engine, the aircraft is being grounded and the engine replaced,” DGCA said.

As per the data with DGCA, there have been nine incidents of in-flight shutdown/rejected take-off/ air turn back due to glitch in the main gearbox and low-pressure turbine in India as compared to 28 such incidents in the world since January 2019. In terms of neo aircraft, India has 127 A320neo aircraft spread between IndiGo with 92 such planes and GoAir with 35. Globally, there are 436 neos in operation.

Pratt & Whitney has been in the spotlight in the Indian aviation space since 2016 when India's largest airline IndiGo started facing delivery delays in A320neo aircraft amid issues related to cooling down and a start-up time of the engine, reliability, combustion chamber lining, oil seal and fan blades.

While the issues related to combustion chamber distress, No.3 bearing seal failures and high-pressure compressor, rear knife-edge seal failures have been addressed, Pratt & Whitney is in the process of implementing mitigation actions in respect of gearbox failure, low-pressure turbine failure and engine vibration.

“The issues related to MGB (main gearbox), LPT (low-pressure turbine) and vibration are being addressed by the manufacturer by implementing necessary modifications on the related parts. The engines removed due to any defect or because of scheduled removal are sent to the engines shops, where necessary maintenance or modification is done,” DGCA said.

In issues related to gearbox failure, the software update will provide immediate relief but more robust gear design has also been put into effect from July to address the matter on a long-term basis.

"20 engines with modified gear (Indigo-14 and GoAir 6) have been received. In issues related to low-pressure turbine (LPT) failure:- Redesigned, more durable new LPT stage 3 blades are being incorporated in new production engines, and at the MRO during shop visit. 47 such engines with new LPT blades (Indigo 40 and GoAir 7) have been received,” DGCA said in a detailed statement.

While the engine failure related to the main gearbox is expected to be contained after the software update, engine failures related to Low-Pressure Turbine blade damage are being addressed by providing new LPT 3rd Stage blade.

“The fault being captured at an early and incipient stage before the failure of the engine. These have resulted in an increased number of engine removal. Restriction on import of engines with un-modified MGB and LPT will result in the early replacement of affected engines,” DGCA added.

As a result, Pratt & Whitney has been directed to ensure more availability of spare engines for Indian operators to prevent grounding of aircraft due to removal of engines, DGCA said.

DGCA also reiterated that all new inductions of A320/321 neo aircraft after August 2019 must be installed with modified main gearbox and new modified 3rd stage low-pressure turbine blades.

First Published:Aug 28, 2019 9:29 PM IST