Deadline extension: IndiGo has time till May 31 to replace all P&W engines

The Directorate General of Civil Aviation (DGCA) on Monday decided to extend the deadline for IndiGo to replace all unmodified Pratt and Whitney (P&W) engines on A320neo aircraft from January 31 to May 31.

Prompted by multiple incidents of engine shut-downs, the DGCA had earlier directed IndiGo to replace both low-pressure-turbine (LPT) engines of its 97 Airbus A320neos fitted with P&W engines by January 31, 2020. The extension came after IndiGo submitted a plan to the regulator requesting time till June-end to procure and replace 135 engines. Mitigation measures will be put in place until the replacement exercise is completed, DGCA said.

IndiGo has already placed at least one modified engine in each of its A320neo fleet, a DGCA statement said.

“As per the initial count a total number of 120 modified engines were required to be placed on the fleet of M/s IndiGo, however, this number is likely to be about 135,” DGCA said. The aviation regulator expects that around 70% of the airline’s A320neo fleet’s engines will be modified by the end of this month.

DGCA also directed that aircraft with unmodified engines in IndiGo’s fleet will not be allowed to fly after May 31. The airline did not respond to FE’s queries till the time of going to press.

DGCA first directed IndiGo to replace old P&W engines in A320neos in October 2019, following multiple incidents of in-flight shut downs. Later in November 2019, IndiGo was barred from operating some aircraft with older engines. DGCA had earlier mandated in November 2019 that every new aircraft being inducted into IndiGo’s fleet should replace the older aircraft with unmodified P&W engines on the same schedule. As a result, IndiGo, India’s largest airline by market share, has had to slow down induction of new aircraft.

DGCA had last year inspected A320neos fitted with old P&W LPT engines, and found that those which have operated over 2,900 hours were more prone to damage.

Meanwhile, P&W has also informed the regulator that fractures in the mid-turbine frame (MTF) piston seal contribute to about half of the incidents involving the LPT engines. “It is expected that the mitigation measures put in place, such as the introduction of MTF Piston Seal (inspection) in addition to the existing boroscopic inspections and introduction of an alt climb procedure will help in containing the engine failures,” the DGCA said. The alt-climb process reportedly applies less thrust on the engines. IndiGo’s pilots were reportedly revving the A320neo engines at full thrust right after takeoff, leading to quicker wear and tear of the engines.

Following DGCA’s directives, American Fereral Aviation Authority (FAA) had also issued an airworthiness directive in November last year mandating the removal of unmodified P&W engines from service. Similarly, European Union Aviation Safety Agency (EASA) had in December sought replacement of at least one of the affected engines by March. In its airworthiness directive, the FAA observed 21 instances of failures of the affected LPT engines between 2017 and June 2019.

According to the analysts’ estimates, IndiGo’s capacity growth guidance (measured in available seats kilometres) was lowered for FY20 to 20% from the earlier 25% in the wake of DGCA’s order.

Source: Financial Express