India’s Directorate General of Civil Aviation (DGCA) has identified the first known incident involving the gearbox of the PW1100G geared turbofan engine on the Airbus A320neo.
A “main gearbox failure” caused one of 42 premature engine removals so far of PW1100G-powered A320neos, according to the DGCA. The failure was “detected as a metal chip warning”.
The new issue was revealed in a one-page brief about the PW1100G engine posted on Twitterby Tarun Shukla, an Indian journalist for Mint, the financial newspaper of the Hindustan Times. A DGCA spokesperson provided Shukla with the document, Shukla confirms to FlightGlobal.
The document also describes another 41 premature engine removals caused by two known issues with the PW1100G, including 28 attributed to distress in a carbon-air seal for the No. 3 bearing and 13 caused by degraded combustion chambers.
DGCA released the brief as it continues to investigate the root cause of an in-flight shutdown of a GoAir A320neo with PW1100G engines on 8 February.
The incident prompted the DGCA to order India’s two A320neo operators — GoAir and IndiGo — to conduct borescope inspections on engines with more than 1,000 flight hours, a reduction from the 1,500h interval recommended by P&W. DGCA also orders airlines to immediately ground the A320neo if a metal chip detection warning coincides with a gearbox failure, revoking a 10 flight-hour cushion provided in the A320neo’s approved minimum equipment list.
Despite the string of incidents that has dogged the PW1100G fleet since entry into service in January 2015, P&W officials have insisted the geared turbofan architecture, which includes the 30,000hp-rated fan drive gear system, remains sound as it deals with carbon-air seal and combustion chamber problems. The company doesn’t step back from that claim in a statement to FlightGlobal addressing the findings in the DGCA document.
“Pratt & Whitney, with the support of Airbus, is in close contact with the Indian authorities to address technical issues and provide solutions in a timely manner. We are actively working with our customers in India and are supporting them in their daily operations,” P&W says.
The DGCA brief on the PW1100G reports that P&W plans to deliver a fix for the degraded combustion chamber in September. A planned fix for the carbon-air seal around the No. 3 bearing should be ready by April, the brief suggests.
CLARIFICATION: This article was updated to make it clear that the 30,000hp-rated fan drive gear system at the heart at the geared turbofan architecture is a different component than the main gearbox.