We all know there's not much in the way of 19 seaters and no 30 seaters currently on the market, some (for example the EMB120) find their lives coming to an end due to lack of props, or other parts, as well as the obvious economic issues with flying that small of aircraft. However there still does seem to be a market to some extent with them soldiering on in Norway, Australia, the UK etc, filling a niche that so far at least no other plane has been able to. And with airlines like Wideroe pushing for a new generation but a small market making it pretty difficult or impossible to justify a new aircraft, I was wondering if and under what conditions a step change in engine technology via the GE Catalyst could bring new life the segment. The reason I put this in tech ops is my question revolves in some sense around the HP numbers etc, and whether the increased fuel efficiency, and decreased size and weight due to the Catalyst's 3D printing technology would not only be enough to help on the cost side, but also if it's technically feasible on physics side. Figured no better folks to ask then those who have more technical background than I do (while I started in Aeronautical Engineering in college I finished in Econ )

Here's some information to guide the conversation. (all HP numbers for single engine)

GE Catalyst
850 to 1600 HP

DHC
DHC-8-100 PW121 1800 HP

Dornier
328-110 PW119B 2180 HP

Embraer
Emb120 PW118 1800 HP

Jetstream
41 TPE331 1650HP

Saab
340 B CT7-9B 1750HP

With regards to the 19 seaters my assumption as the Catalyst is meant to be a PT6 competitor that it wouldn't be that hard to reengine those (if a market existed) I don't know if GE has looked into that but would be interested to know if they had.

With regards to the 30 seaters I guess my question is that are the benefits of the Catalyst going to be most felt at the top bottom or middle of the HP range? Are engines like stretches where often the most efficient configuration is at the top end of the range? If so would the 20% fuel efficiency gain claimed over the PT6 widen over the low end of the power band for the PW118/19 CT7 type engines that powered props in the past generation? Could utilizing even at a little less power a Catalyst due to it's smaller size, less weight, and greater fuel efficiency enable a DHC8-100 or EMB120 for example to utilize the slightly less powerful Catalyst but still have similar performance at much reduced fuel and maintenance costs? Or would pushing the envelop of the HP range of the engine degrade the advantages as it would be running at the high end of it's design envelop?

Thanks for the information! It's not often we have such drastic step changes in engine technology especially in this market, and I think it does beg the question of whether a reengine market will open for the engine along with new builds.

I hope some engine performance guru will chime in.

For one, you have to distinguish between 4 approaches
- where then engine is physically unchanged but the throttle is pushed up or down, it's got a different gearbox or prop, this airplane uses more bleed than that one, etc.
- where the engine is physically unchanged excepting a handful of parts (typically the combustor, the turbine airfoils, and their cooling system). This can allow a notable increase in temperature and hence power. But, it often comes with a loss of efficiency (not always).
- the engine "core" is unchanged or has modest changes, but the low shaft is mostly or entirely new.
- where the majority of the engine is changed. The physics of the engine are largely unchanged (T-S diagram, firing temperature, compression ratio, etc.) but it's all gotten bigger.

I don't know exactly which strategies GE is aiming at when they listed that range of 850 to 1600 HP. PW's 4000 series included 112 inch, 100 inch, and 84 inch fan versions on a "common core" (3rd / 4th approach) for vastly different thrust categories (56 to 98k lb thrust, IIRC) but that seems like overkill for a small market small engine - a lot of engineering effort for minimal sales. So I'd guess the first two are on the table... But I wonder if the power can vary that much without at least some changes in the engine, not sure the 1st covers it.

Wow, I just took a look at the GE Catalyst. Looks like it could be a PT6 killer. Designed initially just for the Cessna Denali, I wonder how many other airframes into which it would be incorporated. Might future versions of mainstays like the King Air switch from the PT6 to the Catalyst? If they didn't, they would be at a competitive disadvantage. They've already been able to reengine the aircraft with two others: The TPE, and the shortlived Orenda piston engine.

GE would need a new airframe to make this worth the effort … only feasible opportunity maybe the relaunch of the 328 T in Germany

crjflyboy wrote:

GE would need a new airframe to make this worth the effort … only feasible opportunity maybe the relaunch of the 328 T in Germany

Yep, that or a new DHC-8-100 etc... Is there any updates on the 328? Although I'd think it might be too built to be powered by a bigger engine that slowing it down that much might not work...

iceberg210 wrote:

crjflyboy wrote:

GE would need a new airframe to make this worth the effort … only feasible opportunity maybe the relaunch of the 328 T in Germany

Yep, that or a new DHC-8-100 etc... Is there any updates on the 328? Although I'd think it might be too built to be powered by a bigger engine that slowing it down that much might not work...

The German entity that owns the production rights was at the Paris show … they are searching for more partners to make it happen.

A 328 T with the catalyst engines should sell.

https://328.eu/2019/06/328ssg-will-be-e ... halet-258/

Well, it sell too well with competitive turboprops 25 years ago. 217 built, 24 in service. It’s a plane in search of a market.

GF

GalaxyFlyer wrote:

Well, it sell too well with competitive turboprops 25 years ago. 217 built, 24 in service. It’s a plane in search of a market.

GF

Let's be honest ... it was very late to the party when it first came out and when it finally did CRJ mania had kicked in.

There will no further SF 340's or Jetstem 41's manufactured again, a lot less competition.