Pratt & Whitney says it is "happy to take the blame" for the delay to the first flight of the Irkut MS-21 narrowbody.
Speaking at a press briefing on 10 July, Bob Saia, vice-president next generation product family, commercial engine programmes at the Connecticut-based manufacturer, said delivery of the first PW1400G engines to Irkut has been pushed back four months to early 2015. This, he says, was due to it taking longer than expected to receive a final contract and detailed technical requirements from the Russian airframer.
The 28,000lb-31,000lb thrust engine for the MS-21 has 90% commonality with the PW1100G which will power the Airbus A320neo says Saia, with the key differences around the integration of the powerplant into the aircraft's hydraulic and electrical systems.
Saia adds: "Irkut wanted first flight at the end of 2014 but it's like baking a cake, it takes a certain amount of time in the oven. If you start a little bit late then you finish a little bit late.
"If they say it's my fault then I'm happy to take the blame. I'm happy with where we are - I'll take the blame for being a good supplier."
The date for entry into service has not moved, he notes,
Design for the PW1400G is frozen, Saia adds, but P&W will perform further optimisation work as integration with the aircraft proceeds.
Overall, the geared turbofan engine programme is on schedule, says Saia. P&W has logged 3,100h of flight testing on its two Boeing 747SP flying test beds using the PW1200G for the Mitsubishi Regional Jet and the PW1500G for the Bombardier CSeries. Certification for the CSeries powerplant is planned for the fourth quarter, says Saia.
The MRJ's engine is due to begin certification flights towards the end of the year, following completion of its initial flight test program on 21 June, Saia adds.
P&W is also researching further improvements to the GTF powerplants, including internal aerodynamic tweaks and the use of advanced materials, which it hopes will yield fuel consumption boosts of around 1-1.5% per year through to 2025.
Gear ratios may also be increased on later variants, from 3:1 currently to 3.5-4:1 in the future.