The US Federal Aviation Administration is set to require checks of some Pratt & Whitney PW1000G geared turbofans after oil leaks caused two inflight engine shutdowns.

The US regulator has released a proposed airworthiness directive (AD) to address the risk of fire caused by oil leaking from PW1500Gs, which power Airbus A220s, and PW1900Gs, which power Embraer E-Jets E2.

The proposal, made public on 9 September, cites the risk of oil leaking from a "gap" between the engines' "oil supply tube and the fuel oil cooler".

"The FAA is issuing this AD to prevent failure of the LP10 oil supply tube, engine fire and damage to the airplane," says the proposed rule.

P&W already addressed the issue with service bulletins, released earlier this year, that detail procedures for modifying or replacing PW1500G and PW1900G fuel air coolers and oil supply tubes, say FAA documents.

Contacted by FlightGlobal, P&W does not disclose additional details about the oil leak problem.

The company says it is "requiring inspection and replacement of hardware on PW1500G and PW1900G engines to prevent possible oil leakage between an oil supply tube and the fuel oil cooler".

"Fleet incorporation of the redesigned hardware is already underway," P&W adds. "This activity can be performed on-wing and we are working closely with our customers to ensure minimal operational disruption.”

The FAA's notice would require US-registered operators to inspect the gap between oil supply tubes and fuel air coolers within 300 engine cycles and perform additional inspections within every additional 850 cycles.

They would also need to replace the oil supply tube and cooler during the next shop visit. The FAA is accepting comments about its notice for 45 days.

The FAA did not disclose details about the in-flight engine shutdowns, but a P&W source familiar with the issue says they occurred last year and affected two A220s operated by Swiss.

The oil issue is not related to a Swiss A220 in-flight engine shutdown in July, the source adds. Investigators have sought help in locating parts from that engine, which was powering a flight from London to Geneva.

Other GTF variants have suffered oil-related problems, including oil seal issues affecting PW1100Gs, which power A320neo-family aircraft.

And in 2018 Indian airline IndiGo grounded one A320neo after the pilots received a warning about low oil pressure inside one PW1100G.

India's civil aviation authority attributed that event to improper assembly of a component.