Airbus has stopped accepting new engines from Pratt following higher than normal engine in-flight shut-down (IFSD) and Rejected Take-Off (RTO) involving the PW1100G powered variants of A320neo, which started entering service from January 2016.
Delivery of the A320neo, a more fuel efficient version of its best selling single aisle airliner, have also been paused by Airbus indefinitely.
European Aviation Safety Agency (EASA) had issued a emergency airworthiness directive (EAD) on Feb 9, that warns even possibility of dual engine in-flight shut-down.
EASA says several occurrences of engine IFSD and RTO have been reported on certain Airbus A320neo family aircraft, the A320neo and the larger A321neo.
While investigation is ongoing to determine the root cause, preliminary findings indicate that the affected engines, which have high pressure compressor aft hub modification embodied from engine serial number (ESN) P770450, are more susceptible to IFSD.
To address this potentially unsafe condition, Airbus issued Alert Operators Transmission (AOT) A71N014-18, providing instructions to de-pair the affected engines and discontinue Extended range Two-engine Operations (ETOPS) for aircraft fitted with affected engines.
ETOPS certification allows twin engine aircraft to fly straight, rather than flying close to airports for diversion in case of an engine trouble.
This has prompted many airlines including largest operator of the type, Indigo and GoAir to ground their fleet indefinitely.
Indian budget carrier IndiGo, said it had carried out 69 Pratt engines replacements in 18 months, after multiple inflight shut downs and turn backs, adding replacements were the best possible precautionary measure.
P&W in a statement said, we have identified an issue, which is isolated to a limited number of potentially affected aircraft. We are working to resolve this issue swiftly to minimize disruption.
A total of 113 A320neo family aircraft delivered to 18 airlines, are equipped with these P&W engines, while the CFM LEAP-1A powered A320neo's continue to operate.
P&W's Purepower engine family features a breakthrough GTF architecture, featuring a intermediate planetary gear system, that decouples the main engine fan and the engine core, enabling both to operate at their optimum rotational speeds.
P&W's Purepower GTF engine family powers all the new generation single aisle passenger jets except the Boeing 737 MAX. While the GTF powered Airbus A320neo and the Bombardier CSeries have entered service, the Embraer Ejet E2 family, Mitsubishi MRJ family, the Russian Irkut MC-21 and the Chinese COMAC C919 are under flight testing.
The P&W Purepower GTF engines while key to the improved efficiency of these aircraft, had a long string of problems during testing and in service.
The A320neo specific PW1100G has been hounded with technical problems and reliability issues, while its variants were less affected.
Interestingly, the PW1100G is the highest thrust variant (110-160 kN) in the engine family and also the most number in operational use.
Initial issues with the engine delayed planned A320neo service entry in 2015 by one year to 2016.
P& W also struggled to ramp up production resulting in Airbus falling short of its A320neo delivery goals in 2017.
During ground testing, a PW1500G engine fitted to a Bombardier CS100 suffered an uncontained engine failure in 2014, while one of the two PW1200G powering the Mitusbishi MRJ experienced a in-flight uncontained engine failure during flight testing in 2017.
The flight testing of the Embraer E190 E2 powered by the PW1990G has been by far trouble free, while the MC-21 and COMAC C919 are in their early stage of flight testing, clocking only very few hours with the PW GTF engine.
Since entering service in January 2016, Pratt says these engines have more than 500,000 hours of passenger service, and demonstrated its promised ability to reduce fuel burn by 16 percent to reduce nitrogen oxide emissions by 50 percent to the regulatory standard, and to lower the noise footprint by 75 percent.
