IndiGo shifts to LEAP engines: Here's a look-back at the problems the airline faced with Pratt & Whitney

After facing a number of problems with Pratt & Whitney (P&W) engines, InterGlobe Aviation, parent of India's largest airline IndiGo, on Monday signed a $20-billion contract with CFM International for installing the latter's LEAP-1A engines in the company's new aircraft.

Reuters reported earlier in June that IndiGo had chosen CFM over Pratt for what was one of the largest jet engine orders and that the deal would be for more than 600 engines, including spares.

The airline is acquiring more aircraft from Airbus —  280 Airbus A320neo and A321neo planes. In these planes, the airline is looking to fit LEAP-1A engines.

Among the LEAP variants, LEAP-1B is fitted in all Boeing's 737 MAX series aircraft, even in Boeing 737 MAX 8, which faced a worldwide grounding after two deadly incidents, the Lion Air and Ethiopian Air crashes. However, the reason speculated is not due to engine failure, but because of other issues in the aircraft.

IndiGo was forced to ground their aircraft periodically since 2016 because of problems in the P&W engines. The airline had inducted Pratt engines in 2016.  The flaws in the engine's design have led to delayed aircraft deliveries. Pratt & Whitney also had to pay millions of dollars in compensation to Indigo over these glitches.

In 2018, IndiGo faced more than three cases of engine shutdown and flight cancellations.

In one such case, which occurred on March 1 last year, a Kolkata-bound flight had to make an emergency landing because the engine reportedly faced  'high vibration' leading to a 'stall' warning.

The problems with the engine widened to operational ones, which meant a start-up time delaying turnaround of aircraft, problems with the seal of the engine and durability issues with the turbine blades.

The issues have prompted the Directorate General of Civil Aviation (DGCA) to ground 11 Indigo aircraft in March last year, citing potential risk to civilians. DGCA also tightened the scrutiny on the turbines leading to higher removal of engines. This led to a shortage of spare engines and compelled the airline to keep its planes grounded till October.