Certification of the Pratt & Whitney PW1200G geared turbofan is expected in the "latter half" of 2014, or at least six to 12 months after the scheduled first flight of the Mitsubishi Aircraft MRJ regional jet in late 2013.
Bob Saia, P&W's vice-president of the next generation product family, disclosed this while discussing the company's crowded development schedule.
This includes the different versions of the geared turbofan core selected to power new aircraft in development by Bombardier, Mitsubishi, Airbus, Irkut and now, Embraer.
Mitsubishi, when contacted, however, says the flight tests for the MRJ can be conducted ahead of engine certification.
A spokeswoman says the programme is on track to perform its first flight in 2013, although she would not comment on whether the company is aware that certification of the PW1200G has been pushed back.
"We understand that the type certification schedule of the P&W engine is supporting the first aircraft delivery of the MRJ as planned," she adds.
She points out that Mitsubishi can start the test flights before the engine completes certification.
"It is not a problem if the certification of the PW1200G geared turbofan is in the latter half of 2014, since our first aircraft delivery is scheduled for 2015," she says.
The MRJ was originally expected to enter flight testing in late 2011. But Mitsubishi, in September 2009, delayed the milestone to the second quarter of 2012. First flight was again delayed in April 2012 to late 2013.
Meanwhile, P&W decided in September 2012 to delay certification of the engine to mid-2013, allowing the company to concentrate on readying the PW1500G for flight testing on the Bombardier CSeries by June.
Mitsubishi has provided no indication that the MRJ has fallen further behind schedule. In December 2012, SkyWest finalised a deal to buy 100 MRJ90s, with Mitsubishi reaffirming that the aircraft is "currently scheduled" for delivery starting in 2017.
The last delay for the MRJ programme was driven by the need to complete more detailed engineering work on the aircraft, according to Mitsubishi. Japanese regulators also had not finalised certification requirements for the MRJ's production process, requiring more time for Mitsubishi to become compliant.