NEW DELHI: India’s aviation regulator Directorate General of Civil Aviation (DGCA) on Monday directed IndiGo to replace an engine each on at least 16 of its Airbus A320 Neos within a fortnight. The direction came after last week saw as many as four IndiGo Neos safely returning to where they took off from after their Pratt & Whitney (PW) engines stalled and experienced high vibration. If PW is unable to supply the required 16 new engines within 15 days, Neos awaiting engine replacement will be grounded till that happens. Three cases that led pilots to switch off the snag-hit engines (called commanded inflight shutdown or IFSD) happened on consecutive days —October 24, 25 and 26. Since twin-engine aircraft can land safely on one engine, these three A320 new engine option (Neo) did so at their origin cities. In addition to these cases, another IndiGo Neo experienced high-engine vibration due to which it too had to return.
Alarmed at the sudden spurt of such cases, DGCA chief Arun Kumar asked his top technical officers to examine the issue threadbare over the Diwali weekend and then dispatched a six-member team to IndiGo’s Gurgaon office on Monday to “review maintenance and safety data”. IndiGo has 250 planes in its fleet. Of them, 97 are Neos. Among the Neos, about 49 have got new and modified PW engines. The remaining 48 IndiGo Neos have older engines that are yet to be replaced by the ones modified to reduce their snag incidence.
The regulator found the problem is happening with PW’s unmodified engines that have flown for over 2,900 hours in climb phase. Unmodified engines that have flown for less than 2,900 hours are not yet showing this trouble.
Arun Kumar said: “About 16 Neos have unmodified (PW) engines that have done more than 2,900 hours on both wings. They will need to be fitted with one modified engine in 15 days, failing which, the Neos (which have not received a replacement engine) shall be grounded. This decision has been taken after studying the pattern and evaluating the risk.”
An IndiGo spokesperson said: “We are continuing to work with the authorities and will take necessary actions, as required, going forward.”
The airline’s top brass met DGCA officials on Monday afternoon. “GoAir also uses the same combination of PW-powered A320 Neos but their incidence of snags is lower. GoAir takes off with lower thrust. We tried that with IndiGo but still the trouble persisted,” said an official probing this issue. IndiGo has some brand new A321 Neos with Airbus in Europe which are going to be delivered to it shortly. The regulator has suggested getting engines from these planes as replacement for the 16 A320 Neos to complete the job in 15 days and avoid grounding of aircraft in the October to mid-January peak travel season.