PW810 finds its niche via airliner industry’s back door

AINonline
May 17, 2008, 11:12 PM

What presented the impetus for the PW810’s development?
When we started to talk about the PW800 family [in the late 1990s], we were talking about an engine for the next generation of regional aircraft.
We’re talking about an advanced turbofan in the range of 12- to 15-, 16,000 pounds of thrust. And we had a partnership back then with Snecma on the SPW14 and then the SPW16. But after our adventure with Snecma on the SPW16 we launched the PW600–the PW800 technology demonstrator. And again the concept was to demonstrate an advanced turbofan, but we were also including a geared concept into this.

Why didn’t the Geared Turbofan concept take hold in the PW800?
First of all, we had some very significant, good learning with the geared concept on the original PW800 technology demonstrator. But there was no new platform coming in for a new regional aircraft…and the benefits, when you go down to 10-, 12,000 pounds of thrust, were not as significant as they are in the 20- to 30,000 range.
So, one, there was no new application. And, two, the benefits were just slightly better than a conventional turbofan for a regional application–a low-end regional application. What I mean is a 50-seater; this is where we were looking back then, this is where the market was at. But we kept on developing the PW800 technology demonstrator, not with a focus on a gear system, but with a focus on the rest of the engine. So material technology, aero technology, the cooling system…so we kept on improving the 800 for a conventional application. And basically by then we were targeting the business aircraft side.

So you don’t see the GTF finding its way into to such a small platform?
I don’t want to say ever. We’re doing some analysis right now, so we’re looking at the potential tradeoffs. I mean, for sure, one thing that the geared turbofan would bring to any aircraft, whether it’s a business aircraft or a regional application or a single-aisle application, is noise benefit. We know that. The other thing that it would bring that we know is SFC benefit.

Now the question is how big do you need to make the fan to fly at 50,000 feet and Mach 0.85? That’s where it’s not obvious. The large business aircraft fly at 45,000 feet, so when you certify an engine for like a Global Express, a G550, these types of long-range applications, you’ve got to be able to fly at 50,000 feet. So, with less air at 50,000 feet, you have a higher bypass ratio, so you need to make a bigger fan.
The bypass thrust at that altitude is more challenging. You need the propulsive thrust coming from the engine. That’s the reason our bypass ratios are smaller for business aircraft applications.

Anyway, I don’t want to say it will never work, but right now it’s not our focus.

Doesn’t Honeywell make a small, GTF-type engine?
They are still running their TFE731, which is a geared fan. I think there are benefits in that you can maybe stretch the family a bit more because you’ve got one more set of variables into the engine, so you can play with the fan size and the gear ratio, but I’m not sure its adding benefit or value to fuel burn, thrust, power-to-weight ratio and so forth.

So what sets the PW810 apart from other engines?
It’s got a few things. If you look at the combustion system, we are leveraging the latest, the greatest within the Pratt organization. We’ve got the Talon technology that is coming from the Pratt & Whitney East Hartford group.

Is this the only small engine with the Talon technology?
No, we have the Talon technology on the PW307, which probably is the best engine in its class from an emissions standpoint. What that combustion technology does is optimize NOx, so the combustion efficiency. So the higher efficiency you have, the lower NOx you have.

Another thing that we have with this engine is a very aggressive, a very good power-to-weight ratio. I’m not sure that aggressive is the right word…a very competitive, efficient power-to-weight ratio. So we end up with some very good power, low weight.

We have also optimized the material in the engine, so we have lower-weight types of materials, like our Pratt proprietary alloy. And we have also much higher temperature material in the back end.

So you put all of this together, what we end up with is an engine that is lighter for the thrust that it produces. It’s an engine that is more efficient from a fuel burn standpoint. We have very good SFC performance, and we have the Talon technology. As a result of that, what you have is a better combustion process. You have lower emissions overall because you’re more efficient, so you have lower NOx, lower CO2 and lower carbon monoxide.

Which engines do you consider the main competitors to the PW800?
It will compete against the CF34 and the AE3007, and maybe the new Rolls–the RB282. We believe we have the best thrust-to-weight ratio right now. Our selection at Cessna would say so. But of course I’m sure our competitors would say their selection at Dassault would prove different.

Why would a customer choose the PW810 over the RB282?
If you looked at the technology, our technology on the PW800 is more mature. Our technology readiness level has been higher because we’ve been working on that for a longer period of time. So I think that is one reason.

The second reason is that we have always delivered on our commitments. Another reason is we have a very large aftermarket network, probably the most comprehensive in the industry. We’ve got more than 43,000 engines flying today in 190 different countries around the world.

Are you still looking for risk sharing partners?
We are still defining the details, but we have an MOU with MTU right now.

Will MTU provide the high-pressure compressor?
Yes. It is going to be a joint effort between Pratt U.S. and MTU.

What part of the engine would other potential partners contribute?
We’re going to look at different components depending on the capability of the partner we’re going to select. So depending on which partners come in, what we share on the engine might vary. We’re exactly in this process right now and I want to be careful because it’s a pretty competitive process.

Where will final assembly take place?
We haven’t decided exactly where. It could be at one of our assembly and test facilities. We have three right now. It’s going to be between Ontario and Quebec. We have facilities in Longueuil, outside Montreal, and some in Mississauga, Ontario.

So what sort of volumes do you anticipate?
If you look at the market size, we believe it’s a market of probably 300, 400 aircraft per year. I’m talking the large and ultra-large business aircraft. We don’t know what portion of that we would capture over time, but if you looked at Cessna’s projection, they’re talking at least 50 aircraft a year for the Columbus.

Could the PW810 serve applications other than the Columbus?
Absolutely. But not likely before the Columbus, unless it perhaps involves a re-engining of an existing aircraft, which is not very likely.

If you look at what is happening in the industry right now, everybody’s coming up with new platforms. So I think that the next application is going to be another new aircraft. It could be at Dassault, Gulfstream, Bombardier–these are the kind of large aircraft OEMs are likely to launch.

There really isn’t an application in regional jets for this size engine anymore, is there?
Not today. It’s interesting, because when we launched the PW800 it was for a regional jet. We kept on developing the technology because we wanted to be ready for the next generation of regional jets, and now the business aircraft are coming first.

It’s not obvious to us if there will be a replacement 50-seat regional jet…a 70-seater, a 90-seater…if you have the right technology, maybe. But we believe when you get into that size of aircraft, you go to the geared turbofan because then the benefit is there–the mission, the altitude they fly, the speed, the range. So I’m not sure where a conventional PW800 advanced turbofan would go in a regional application going forward. It’s not obvious to me. It could take forever [for a new 50-seat jet to reach the market]. And even then, there could be benefit in a geared fan for a 50-seater because the technology has evolved.

Would the PW810 work for larger business jets at some point?
I see the PW800 addressing the business aircraft market clearly. Could there be some benefit in the geared turbofan for very large business aircraft? We don’t think so. We’re not going to close our eyes on that, we’re going to take a shot at it, make sure we access the technology for that specific type of mission and application, and then we’ll see. But the PW800, from eight, nine thousand pounds of thrust up to 17,000 pounds of thrust–it’s pretty clear.

Have you already performed studies into larger variants?

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