ATR, Pratt & Whitney launch new turboprop engine

By Judson Rollins

November 16, 2021, © Leeham News: ATR and Pratt & Whitney Canada jointly announced a new PW127XT engine for the ATR-42 and -72 series at the Dubai Air Show. The XT designation stands for “extra time on wing.”

Pratt & Whitney says the engine will offer 40% greater time on wing, 20% lower maintenance cost, and 3% lower fuel consumption than the current-generation PW127M.

The 40% time on wing assumes a 60-minute average mission in “benign environments.” The reduction in maintenance cost is driven by a requirement for just two scheduled engine events in ten years. Fuel burn improvements were achieved via a new compressor and updated turbine module.

ATR CEO Stefano Bortoli said at a press conference, “There are plans to improve the propellors.” When asked to elaborate, he declined to provide details.

Air Corsica will be the launch customer for the XT, which can be retrofitted onto existing ATRs immediately and will be standard on all new aircraft from the second half of next year.

The new engine, along with all of P&W’s current lineup, is compatible with sustainable aviation fuel (SAF) blends of up to 50%. The engine maker intends to increase this to 100% in the near future.

31 Comments on “ATR, Pratt & Whitney launch new turboprop engine

  1. Hah! Small Air Corsica, the “national” airline of the Corsica island of France is on the news!

    Funny, but it was also the first French airline to have neos.

    • Some would also add that Corse is halfway italian…
      Funnier to see them as lauch customer for an aircraft from an original French-Italian JV.

      • Napoleon could have been Italian if Italy had owned Corsica for longer. Funny to think about things like that.

        I want to see this engine on the Q400 as well. And to complete the pattern, the launch customer better be Air Canada Jazz or some smaller Canadian airline so the launch customers are the country of origin for both plane and the other for the engine

        • Noah:

          The Dash 8 (now back to its original designation) has a variant of the PW127 that is twice the power of the ATR.

          Ergo, unless PW upgrades that engine, you won’t see any change.

          The layout is the same but the size is different, the same parts don’t fit both (sans a generator and hyu7uali pumps)

  2. “the XT, which can be retrofitted onto existing ATRs immediately and will be standard on all new aircraft from the second half of next year.”

    That’s interesting. Existing operators can make a business case of selling their existing engines & refitting the ATR fleet it with the improved ones.

    Next question would be, does it make sense for an PW127 be upgraded to a PW127XT? Can a PW127 be stripped for accessoires / sub-assemblies to be used on XT’s? What is the commonality?

    Doesn’t help Embraer’s E3 anyway.

    • It may well be that those upgrades are able to be added during overhaul.

      While I applause the effort, what it looks like is an upgraded engine with a fancy title that means nothign in and of itself. Its not a new engine model or a major change from an existing.

      Some very nice performance improvements that make the Dash 8 less competitive (unless the Dash 8 engine is also upgraded, which it may not be as there is low to little demand and no new production on the horizon)

      There is a large existing fleet that would benefit from an upgrade so its possible.

      • I would say “major change” with a new HP and LP compressor and new HP and LP turbine according to others informations….but 3%sfc improvment looks low if such changes are true. Why?
        Retrofit business case should be not easy except if PWC has low price

        • Shades of the Trent 10. Pretty much an all new engine in that case and not all that much fuel performance improvement (which it lacked badly against its listed metric and worse against GenX.

          And it still did not catch up to its own specs and not against the GenX. ANA and NZ have gone on to dump it on future deliveries of the 787.

    • I would imagine existing operators have to provide the old model engine in return for a new one.
      Its been a feature of PWC that they upgrade your existing engines, the existing PW127 series amoung them

      • All mfgs upgrade their engines.

        Most if not all are able to be back fitted to the original.

        The PW4000 was originally considered pretty lame, over the years PW upgraded it into a respectable offering.

        GenX has been upgraded since the last PIP (quite significant ), GE chose not to call it a PIP or advertise it to public though they did the airlines

      • Big Cost and not enough market return.

        ATR is the lower end of the PW127 range and turbo props in that category don’t sell in great numbers. The Dash 8 does not use the same engine so it would not contribute to the engine population.

        PW still makes the quite old PT6. Its not SFC if the whiz bang GE Catalyst engine, but its extremely reliable and easy maint and there are cost savings for that.

        • If it gets into production, there is a good chance it will, the Deutsche D328 will use the PW 127S. Much smaller aircraft but also much faster.

  3. Good news but I believe a 15% improvement in sfc would be possible if the kind of technology used in current model jet airliner engine were implemented. Unfortunately the small market for such aircraft does not support he required investment. That’s perhaps for the best as the resources are best applied elsewhere.

      • I suspect this segment of the market will end up using fuel cell electric propeller propulsion. Because fuel cells are modular they will be able to maintain efficiency of about 60% from 100kW through to 1000kW and simply be stacked to obtain greater powers.

        The improved maintainability and extended service intervals of the PW127XT is absolutely critical and energy saving in themselves. In my current industry I’ve seen projects as large as 500 million dollar collapse on maintainability issue. Maintainers are undervalued but their skills are really in short supply and in some parts of the world impossible to obtain.

        Hence maintainability does save energy.

        • Its far more likely this is where the hydrogen powered TP will come first. Wing wing fuel pods or integrated with the engine pod.

      • It’s not just bypass ratio. The turbine inlet temperature of the PWC127 seems to be around 2200F/1150C whereas the CFM56 is around 1360C and LEAP 1B around 1560. GE9X might be approaching 1700C. Hard to find this data. Then there is also pressure ratio. There is easily 15% improvement there.

        • BPR is not relevant to a Turbo Prop. They don’t work on thrust out the back.

          I have a ref (somewhere) that shows 50 to 1 for a TP.

          The only huge improvement (maybe) is something like RISE in a hybrid from of Turbo Prop.

          An it has a whole set of install issues let alone nothing proven even as a prototype.

          So, yes, more exotic materials and hotter running.

          • The jet thrust on a turboprop is considerable. It is traditional to quote a turboprops power in eshp “equivalent shaft horse power” which is the shaft horse power plus the equivalent horsepower at a certain reference speed.

            Many hours of calculation and I’ve never determined if there is a standard reference speed. It seems to be 100 feet per second, or sometimes 100 mph. 100 foot pounds per second fps ie 1 pound thrust at 100 fps is about 0.18hp. Comes from the equation P=F.v (Power = Force x Velocity). I recall the Germans in early WW2 used 100m/s, 200m/s and the aircrafts top speed as a reference (HeS 022 turboprop).

            The jet thrust of a two stage WW2 Merlin was about 300 hp but with the inches of mercury/psig being pulled at the Reno races they are likely getting 1200lbs thrust.

            I think its not traditional to quote a bypass ratio of a turboprop but it could be done.

            Worth noting that Pratt & Whtney friend and partner MTU build a turbo fans called CRISP and CRISP-II.

            Two of the tricks of this test bed was heat regeneration and intercooling.

            But a 3rd Trick was the variable pitch contra rotating geared fan.

            There are a lot of tricks left in the turbofan. Gearing is coming in but variable pitch is another.

            With microcapillary heat exchangers developing intercooling may be on the cards.

        • Those are much bigger thrust engines where scale makes the improvements worthwhile on very long flights.
          You just cant have very high compressor pressures for tiny airflows in small passages.

          The Dornier 328 jet was an example for a change of TP ( PW119) for a small turbofan, the PW300, which includes some features of a TP like centrifugal compressor. Its BPR is 4.5 and thrust is 5000lb range for takeoff.

  4. only 3% fuel burn improvement on an engine designed in 1992? or 3% vs the 127M which was certified in 2007 (and still, only 3%? in 14 years?)

    given that the new T901 motors have 50% more HP and 25% lower SFC than the T700, 3% is disappointing.

    • Really more of a PIP than a new engine. In that case a 3% improvement is in the right ball park and a 40% improvement time on wing is pretty impressive.

      • I have to believe that a fully modern turboprop engine would be able to get on the order of 30-40% improvement over a 1992 design. part of the reason the T901 _only_ gets a 25% improvement is the design constraint to exactly match the physical dimensions and aircraft interfaces of the T700. if they had been free to play with intakes, exhausts, turbine diameters etc they would have been able to get a lot more.

        • More, but I don’t think you will see 40% improvement.

          There have been some new Turbine engines (helicopters() and those did not get 40% improvements in SFC.

          Granted they also were going after more horsepower so not an apples to apples. RISE claims a lot (paper claims only ) but they also claim they are an Open Rotor. As there is no jet thrust involved I call it a Turbo Prop.

        • The differences between modern large turbo fans and turbo shaft/props are many.
          Often the better sfc comes from a higher by pass ratio and increased overall presure ratio in a much larger engine
          Something you arent going to see in the turbo-prop/shaft which still use centrifugal compressors and tiny airflows .
          The earlier model T700 was developed in the 1960s and military engines dont worry so much about hours and maintenance that a regional turbo prop would.
          Ceramic components like the T901, forget it unless the government is paying for development and will order 5000 plus.

      • Considering it’s a further evolution of the PT6A it’s very impressive. An engine famous for its reliability.

  5. To those complaining that this “only” gets a 3 percent sfc improvement, o think you’re missing the point. For most turboprop operators, maintenance is a very significant part of their overall operating costs. These are short flights in very efficient airplanes, so don’t burn much fuel to begin with. A 20 percent reduction in maintenance cost is a huge benefit, and may well prevent a few customers from migrating to the new generation of regional jets.

    • Jack:

      I fully get the point on the improvements, its just not a new engine. Its a PIP and good to have it done etc, but spinning it (pun intended) into a new engine is hype.

  6. Flying short flight with a ratio Fh/FC around one, a 20 pc decrease of maintenance cost is indeed significative. IS it through ” on wing” durabiliy

    of non limited life engine parts or the increase of life in FC of those limited life parts ?
    In general consomption at T/O and during climb are higher than in Cruise so for short haul operator a 3 pc sfc decrease might be reached
    My question IS relative to the internal aerodynamic improvment:
    SFC improved by 3 pc when you change” all “rotating compressor and turbine parts
    looks for me:
    -“low”because during the last 10-15 years major avance in profile ‘s aerodynamic have been done
    -“relatively expensive” because those parts are in general the most expensive during complete overhaul.
    Your opinion?
    Anyway future will tell us by knowing which operators in terms of Fh/FC ratio will choose such retrofit.

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