JUST THREE DAYS into 2019, 136 passengers aboard IndiGo’s evening flight from Chennai to Kolkata had the scare of their lives. Shortly after takeoff, one of the engines flamed out, spewing sparks and smoke. As the spluttering engine’s vibrations shook the aircraft violently, panic spread through the cabin. The pilot had no other option but to fly the twin-engine Airbus A320neo back to Chennai.
Airbus A320neo aircraft, which uses Pratt & Whitney (P&W) engines, have been in the news for the past few months for technical troubles. The Chennai incident stood out as it was the first instance involving multiple issues—smoke, sparks, heavy vibrations, a loud bang and a stalled engine.
With a dozen inflight shutdowns reported over the past few months, the government has stepped in. “The ministry has taken serious note [of this],” said civil aviation secretary R.N. Choubey. A high-level meeting was held on January 8, which was attended by representatives from Airbus, P&W, IndiGo, GoAir and officials from the ministry and the directorate general of civil aviation (DGCA). The meeting, chaired by Civil Aviation Minister Jayant Sinha, went on for almost three hours. A slew of directives was issued to IndiGo and GoAir to carry out inspections of the P&W engines, especially the third stage blade on a weekly basis, and an inspection of the engines once they cross 1,000 flying hours as against the regulatory standard of 1,500 hours, and every 500 hours thereafter.
More stringent measures were announced on January 18, banning the A320neo aircraft with the P&W engines from flying on any route without a landing spot within an hour’s flying time. While this could affect flights to the Middle East and Thailand, the government also specifically banned flights to Port Blair, perhaps keeping in mind the engine shutdown on IndiGo’s Kolkata-Port Blair flight on December 27.
The narrow-bodied A320 is one of the most commonly used aircraft in the world for commercial passenger service. Problems began after Airbus went in for an update of the A320 a few years ago. Though the A320neo is used by many Indian carriers, budget carriers IndiGo and GoAir are the worst hit as they have over a hundred aircraft between them which use P&W’s 1100G geared turbofan engines that have been reporting problems. Though Vistara and Air India also operate A320s, they use engines from General Electric.
“There is no cause for alarm,” said Palash Roy Chowdhury, managing director of Pratt & Whitney, India. “Fundamentally, there are no safety concerns. Our engines have been certified by global safety certifiers, including the European Aviation Safety Agency (EASA), and the DGCA. We have also confirmed that there are no issues with the engine design.”
Palash Roy Chowdhury
Yet, for this American aerospace giant, which was banking on the new engine to be its mainstay, the latest safety concern has turned out to be a major problem. Introduced as a low-noise engine that could save fuel by up to 15 per cent and slash emissions and maintenance cost, the engines have been plagued by problems from the beginning. Since the first A320neo with a P&W engine entered service in India with IndiGo in the summer of 2016, there have been 13 cases of inflight shutdowns alone.
“Most of these inflight shutdowns and other related incidents have happened due to the failure of No. 3 bearing seal and the knife edge seal, erosion of combustion chamber material, low pressure turbine rotor blades’ damage and issues related to the main gear box,” said a DGCA source.
“All the issues have been dealt with, except for the latest,” said Chowdhury, pointing out that 95 per cent of the fleet in India has been retrofitted for the issues detected earlier. “Indications are that the latest occurrences, which have been noticed post a million flying hours, are related to the main gear box. Give us a few weeks and we will get to the root cause,” he said.
IndiGo, too, is trying to allay worries. “Inflight shutdown rates on account of Neo engines in India is well within the regulatory limit. [We have] averaged 0.02 per 1,000 engine flight hours, which is considerably lower than the global benchmark of 0.05 shutdowns per 1,000 hours,” said an email response from the airline. IndiGo, however, did not divulge the number of A320neo aircraft grounded since the latest government order or how it has affected its operations.
There is also the issue of public perception, as reports about engine shutdowns emerge on a regular basis. On January 21, an IndiGo flight from Lucknow to Jaipur operating with an A320neo, had to return to the Uttar Pradesh capital as its engine stalled midair.