Yeah, I want to be one of the first pilots to fly behind a 3D printed entirely new turboprop on a single engine aircraft.

What is new in terms of design about turboprops?
The fundamental aspects, tolerances and materials are well known. Even methods of cooling turbine blades is well understood which work in the lab but are impractical for production. GE also has rather extensive experience designing and building turbines. So I would expect the in-house knowledge to be rather sufficient to minimize risks.

This really comes down to manufacturing. GE has been doing additive manufacturing for a few years based on the PR. If I read the press reports correctly, most GE engines have additive manufacturing involved at some stage. Further, GE has been using this technique for prototyping for even longer. When you combine those factors; with the newly formed a division a year ago to sell the capability on the market; it sounds like the company is betting its future on this technology.
With the size of the company, and how conservative they have to be when dealing with turbines, that is one heck of a bet. The result, I think is a gut instinct on my part that GE is farther ahead in terms of resolving and anticipating problems than many of us on the outside can appreciate.

Tim

How new materials and methods stand up to higher heat and stresses.

The point of advancement on engine design is higher compression ratios and higher temperatures. That is where efficiency comes from but it puts a lot of stress on the material design.


And yet the front end of an A380 engine came off.

And yet the #3 bearing on a Mustang engine failed.

And yet the Eclipse engine needed a new burner can.

And so on....

The point is that operation in the field by customers will reveal weaknesses that won't be caught by design or testing. Every complex product has this issue.

The theme above was that all those failures resulted in no serious issue to the aircraft because they were multi engine airplanes. With a single, the risks associated with engine failure are dramatically worse.

The PT6-6x engines powering the SETPs today were first used on twins (King Air 300 for example). The GE ATP engine's first use will be a single. That changes the risk profile for product introduction.


And yet I bet the engine will have numerous service bulletins after it enters service.

Mike C.

Oh god. Here we go. This is the new SF50 thread.

It'll never work. Can't be done. Everyone is gonna go bankrupt..... blah blah

Yup. It's going to be a disaster!

Engines fail, always have... always will.

I’m King Air to the core, you guys know that... but when I look at Textron’s display here at NBAA they have models of all of their current production aircraft starting at the C90GTx and ending at the Hemisphere, it’s clear that the future of Textron is jets.

They showed their cards with the CESSNA Denali... in the lineup you see the Caravan, Denali and then into M class and CJ class jets. Between the Denali and the M2 they’ll effectively replace the vulnerable C90 and likely the 250 as well. There will be 350’s for decades to come, but smaller turbine airframes will likely end up as singles.

Mike C.

The material is not "new". It actually is old fashioned welded metal. Just one little drop at a time. So it is fairly well understood.

As for the remainder of your points, I agree. The old adage that:

Applies.
I was thinking more fundamental problems. Such as not making power, controller failures, structural failures, design failures....

Versus, a single part failing, such as the bearing. Single parts failing I think are to be expected. The only answer to having the experience is to over engineering the design. But then you lose efficiency...

It is a tough balancing act.

Tim

How new materials and methods stand up to higher heat and stresses.

The point of advancement on engine design is higher compression ratios and higher temperatures. That is where efficiency comes from but it puts a lot of stress on the material design.


And yet the front end of an A380 engine came off.

And yet the #3 bearing on a Mustang engine failed.

And yet the Eclipse engine needed a new burner can.

And so on....

The point is that operation in the field by customers will reveal weaknesses that won't be caught by design or testing. Every complex product has this issue.

The theme above was that all those failures resulted in no serious issue to the aircraft because they were multi engine airplanes. With a single, the risks associated with engine failure are dramatically worse.

The PT6-6x engines powering the SETPs today were first used on twins (King Air 300 for example). The GE ATP engine's first use will be a single. That changes the risk profile for product introduction.


And yet I bet the engine will have numerous service bulletins after it enters service.

Mike C.

Maybe they need to add a chute.

It is the first combination in the turbine world of:

Totally new airframe
Totally new engine
New manufacturing processes
Single engine airframe

Just saying the risk profile here is higher than usual, and the rapid development pace is not reducing that any, either.

As for the "not the first rodeo", it wasn't Williams first rodeo either when they were to supply the first Eclipse engine, the EJ22. We all know how that turned out.

GE may hit a home run, I hope they do. But I'd be cautious.

Mike C.

You guys are just funny.

When I get my SETP, I will fly home to Europe or from Europe just because I can.
Doug, you’re coming with, you just don’t know it yet.
Mike will pass, I’m sure.

Real-time monitoring of the engine is likely to throw up a flag before failure. That seems a major advance to me, reducing costs and enhancing safety.

Ashley

With just the PC12 and PC24, Pilatus can sell against everything Textron has to offer.

I think Cessna, Beech, Textron, or whoever they want to be called will do ok with the Denali.
They obviously think there is a market for yet another single engine turboprop.
I think they are extremely late to the game, but also think the Denali is more of a test bed for this new GE engine and other systems.

I think once they are relatively satisfied with this new product, you will see an announcement that they are incorporating some of the new systems into the 250 and 350.
Wouldn't it be nice to have Fadec engine controls, a digital pressurization system, and 1250-1350 lbs. of thrust per side in the 350.

I fly a 2010 model 350i, and other than Fusion, wireless, and a new yoke, that's the only difference in my 350 vs new. Certainly not worth paying 6 million for a new plane.

Hopefully, the Denali will have great success,which will lead to a better 250 and 350!

It has been a year. Have they canceled it yet ?