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N437QX
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Fri Aug 13, 2021 6:14 pm

LAXintl wrote:
At today's Embraer earnings event they had a few more details including images.

SVP of Engineerings Luis Carlos Affonso said the basic configuration for 70-90 seater has largely been settled on, and the commercial team would have more to share later this year.
The fuselage would have the same diameter of the current E jet offering.


Image


Nice! Unique, and innovative.

So many Q400 flights I've done where I wished the engines were in the back. With good performance, F product, jetway accessibility, perhaps IFE with the reduced noise; I imagine this bird will be a heavyweight contender.
 
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alberchico
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Fri Aug 13, 2021 8:33 pm

Wow, this is a huge change from the previous incarnation of this project, I wonder what flaws they found with a wing mounted engine design that prompted them to discard it.
 
minilinde
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Fri Aug 13, 2021 8:57 pm

What is the latest on EIS? Mid 2020s? And what is a realistic EIS timeline?
 
JayinKitsap
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Fri Aug 13, 2021 9:05 pm

Some considerations this moving of the engines to the rear addresses:
- Above the wing engines are more difficult to maintain or do quick checks on at the gate.
- Aren't there some newer requirements for belt armor of the cabin to protect for a blade out. This has moved the area damaged by a blade out aft of the bulkhead and ahead of the APU, fewer things to protect with a lot able to be by careful routing if cables and lines. Could delete the armor probably.
- The props before are quite close to the boarding door, safer and less likely to be damaged in the rear.
- Prop airflow doesn't impact the horizontal stabilizer in the rear, an additional lift surface from the arms holding the engines.
- Could make the wings and forward fuse the same as on E-jets and E2 jets. Just a shorter rear section, same rear bulkhead, different structure to the rear of the bulkhead. Increased commonality.
- quieter cabin
 
flyinggoat
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Fri Aug 13, 2021 11:39 pm

I love the whole idea of props on the rear. I’d like it even more if the props were on the backside of the engines, but this is cool! Like I mentioned I’m my earlier post, the somewhat conventional yet unconventional design should really help with passenger perception towards turboprops. Smart move by EMB I think.
 
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Francoflier
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 12:35 am

JayinKitsap wrote:
Some considerations this moving of the engines to the rear addresses:
- Above the wing engines are more difficult to maintain or do quick checks on at the gate.
- Aren't there some newer requirements for belt armor of the cabin to protect for a blade out. This has moved the area damaged by a blade out aft of the bulkhead and ahead of the APU, fewer things to protect with a lot able to be by careful routing if cables and lines. Could delete the armor probably.
- The props before are quite close to the boarding door, safer and less likely to be damaged in the rear.
- Prop airflow doesn't impact the horizontal stabilizer in the rear, an additional lift surface from the arms holding the engines.
- Could make the wings and forward fuse the same as on E-jets and E2 jets. Just a shorter rear section, same rear bulkhead, different structure to the rear of the bulkhead. Increased commonality.
- quieter cabin


- Much better/safer engine out handling characteristics.

I really like this concept and hope they go through with it. Add the increasing pressure to lower emissions on a regulatory level and this could be how Tprops start encroaching into jet territory and replace them on the regional markets.

I wonder if ATR (/Airbus) are taking notice...
 
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william
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 1:12 am

ThePinnacleKid wrote:
By moving the engines aft I imagine this will greatly help with mitigating cabin noise and also aid "regional" airport ground handling by being able to have the aircraft sit lower to the ground. Hopefully it gets a nice robust set of trailing link gear too.

I can't help but reflect that the aft engined redesign looks like a modern and much larger EMB-123.

Image

Image


Thanks for posting the prototype pic of hte EMB-123. Embraer has a lot of knowledge of rear turboprops. That prototype first flew in 1990.
 
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alberchico
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 1:41 am

Is the 70 seat version expected to be scope compliant ? This aircraft sure looks like a winner. They know that the ATR successor won't enter service until at least the mid 2030's so they have a window to grab as much market share as possible. Then again it's possible that Airbus waits for more cutting edge tech to become mature enough to incorporate in a future ATR replacement, and they beat Embraer with an superior design.

I assume that recycling as much technology as possible from the E2 program will speed things up and lower development costs right ? Are they partly reusing the E2 fuselage or is it a completely clean sheet design ?
 
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DL717
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 3:37 am

avier wrote:
LAXintl wrote:
At today's Embraer earnings event they had a few more details including images.

SVP of Engineerings Luis Carlos Affonso said the basic configuration for 70-90 seater has largely been settled on, and the commercial team would have more to share later this year.
The fuselage would have the same diameter of the current E jet offering.


Image

This design makes a lot more sense than the previous one of the engines mounted on a low wing frame. The engines though would need to be light, or this would bring up the issues like that of the CRJ's, i.e also accounting for future hybrid technology.
They should add some kind of wingtip fences, if it helps in the design/efficiency in any way, that'd look so cool.


You throw a blade with that design and it’s over. No thanks.
 
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keesje
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 7:44 am

Although the pusher props we saw in past design studies and prototypes provide advantages in terms of congfiguration and weight, these puller ones deal with the noise issue (external and in the cabin). The pusher props are noisy because of disturbed airflow, wake hitting the props. Props in the tail make a big difference in the cabin too.

The price you pay is weight. The weight of the engines and engine cowling is carried by the wings, that are far away from the wings vs wing mounted engines. That takes a lot of structure.

Apart from noise an advantage of the tail configuration is that engines are close together. In 1 engine out situations, the asymetric thrust issue is smaller than with wing mounted engines.

I expect ATR to respond with a stretch, new engines and forward passenger door.
 
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 7:58 am

A friendly reminder that all images posted to the forum must be properly sourced and attributed, unless the image is contained in the airliners.net database. Even images that belong to you must still be properly attributed. Thanks.
 
bigb
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 9:22 am

DL717 wrote:
avier wrote:
LAXintl wrote:
At today's Embraer earnings event they had a few more details including images.

SVP of Engineerings Luis Carlos Affonso said the basic configuration for 70-90 seater has largely been settled on, and the commercial team would have more to share later this year.
The fuselage would have the same diameter of the current E jet offering.


Image

This design makes a lot more sense than the previous one of the engines mounted on a low wing frame. The engines though would need to be light, or this would bring up the issues like that of the CRJ's, i.e also accounting for future hybrid technology.
They should add some kind of wingtip fences, if it helps in the design/efficiency in any way, that'd look so cool.


You throw a blade with that design and it’s over. No thanks.


I was just thinking this......
 
Nean1
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 12:40 pm

This configuration clearly favors high performance with a level of comfort comparable to regional jets. It is also possible that Embraer is revising the original assumptions and proposing a solution that is well suited to distances a little longer than typical turboprop trips.

Embraer has a lot of experience in the design of commercial and executive aircraft with engines in the rear of the aircraft and this will certainly help. The landing gear could be much shorter.

I think it's worth looking into the wing design, which should be very clean and have a high aspect ratio. Will Embraer specify wings with slats?

It seems sure that using an advanced FBY system will put this aircraft in a completely new class of TP.
 
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keesje
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 12:54 pm

Nean1 wrote:
This configuration clearly favors high performance with a level of comfort comparable to regional jets. It is also possible that Embraer is revising the original assumptions and proposing a solution that is well suited to distances a little longer than typical turboprop trips.

Embraer has a lot of experience in the design of commercial and executive aircraft with engines in the rear of the aircraft and this will certainly help. The landing gear could be much shorter.

I think it's worth looking into the wing design, which should be very clean and have a high aspect ratio. Will Embraer specify wings with slats?

It seems sure that using an advanced FBY system will put this aircraft in a completely new class of TP.


Indeed, also taking into concern this will be a TP with considerable belly space for standardized gate processes. No maindeck luggage compartment and sizable bins in the cabin for carry on luggage. It comes at a price (weight / operating costs) vs Q400 & ATR ,but certainly a comfort bump up. Even over CRJ's.
Image
https://www.falconca.net/Embraer_175.html

If this design can cruise at 650-725 km/hr, at considerably lower cost, low noise levels and 90-100 passengers in good comfort, flights up to at least 1000nm should be feasible.

Image
https://theflyingengineer.com/projects/atr-9x/fuselage/

I guess Pratt Canada's NextGen Turbo Prop has a clearer EIS window at this stage. 2023-2025 was mentioned a few years ago, but it became a bit quiet in recent years..

Image
source : https://en.wikipedia.org/wiki/Pratt_%26 ... _Turboprop
Last edited by keesje on Sat Aug 14, 2021 1:19 pm, edited 6 times in total.
 
freakyrat
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 12:59 pm

This aircraft will be more efficient than a regional jet on short hops such as SBN-ORD, SBN-DTW, YNG-CLE, AZO-DTW, LAN-DTW, MCN-ATL etc.
 
Nean1
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 1:10 pm

keesje wrote:
Nean1 wrote:
This configuration clearly favors high performance with a level of comfort comparable to regional jets. It is also possible that Embraer is revising the original assumptions and proposing a solution that is well suited to distances a little longer than typical turboprop trips.

Embraer has a lot of experience in the design of commercial and executive aircraft with engines in the rear of the aircraft and this will certainly help. The landing gear could be much shorter.

I think it's worth looking into the wing design, which should be very clean and have a high aspect ratio. Will Embraer specify wings with slats?

It seems sure that using an advanced FBY system will put this aircraft in a completely new class of TP.


Indeed, also taking into concern this will be a TP with considerable belly space for standardized gate processes. No maindeck luggage compartment and sizeable cabin bins. It comes at a price (weight / operating costs) vs Q400 & ATR ,but certainly a comfort bump up. Even over CRJ's.

Image
https://theflyingengineer.com/projects/atr-9x/fuselage/


Having engines that are relatively heavy in the rear of the aircraft and also far enough away from the fuselage because of their diameter will have a major effect on weight. That's why the indication of reduced fuel consumption compared to current regional jets will be modest (~20%).

This aircraft is a more MRJ-oriented competitor than the ATR72.
 
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keesje
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 1:25 pm

Nean1 wrote:
keesje wrote:
Nean1 wrote:
This configuration clearly favors high performance with a level of comfort comparable to regional jets. It is also possible that Embraer is revising the original assumptions and proposing a solution that is well suited to distances a little longer than typical turboprop trips.

Embraer has a lot of experience in the design of commercial and executive aircraft with engines in the rear of the aircraft and this will certainly help. The landing gear could be much shorter.

I think it's worth looking into the wing design, which should be very clean and have a high aspect ratio. Will Embraer specify wings with slats?

It seems sure that using an advanced FBY system will put this aircraft in a completely new class of TP.


Indeed, also taking into concern this will be a TP with considerable belly space for standardized gate processes. No maindeck luggage compartment and sizeable cabin bins. It comes at a price (weight / operating costs) vs Q400 & ATR ,but certainly a comfort bump up. Even over CRJ's.

Image
https://theflyingengineer.com/projects/atr-9x/fuselage/


Having engines that are relatively heavy in the rear of the aircraft and also far enough away from the fuselage because of their diameter will have a major effect on weight. That's why the indication of reduced fuel consumption compared to current regional jets will be modest (~20%).

This aircraft is a more MRJ-oriented competitor than the ATR72.


I agree, but that when a better Pratt engine becomes available & this Embraer has some clear advantages in capacity, speed, luggage, ATR won't sit on it's hands, murmur about moonshot technology, fully understanding the market, free cash flow ( :ouch: ) & watch what happens.. Alenia/Leonardo are market leader in ATR and have been pushing for something bigger for a long time. https://www.flightglobal.com/systems-an ... 61.article

Image
by keesje, ages ago..
 
Nean1
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 1:39 pm

keesje wrote:
Nean1 wrote:
keesje wrote:

Indeed, also taking into concern this will be a TP with considerable belly space for standardized gate processes. No maindeck luggage compartment and sizeable cabin bins. It comes at a price (weight / operating costs) vs Q400 & ATR ,but certainly a comfort bump up. Even over CRJ's.

Image
https://theflyingengineer.com/projects/atr-9x/fuselage/


Having engines that are relatively heavy in the rear of the aircraft and also far enough away from the fuselage because of their diameter will have a major effect on weight. That's why the indication of reduced fuel consumption compared to current regional jets will be modest (~20%).

This aircraft is a more MRJ-oriented competitor than the ATR72.


I agree, but that when a better Pratt engine becomes available & this Embraer has some clear advantages in capacity, speed, luggage, ATR won't sit on it's hands, murmur about moonshot technology, free cash flow, fully understanding the market ( :ouch: ) & watch what happens.. Alenia/Leonardo has been pushing for something bigger for a long time. https://www.flightglobal.com/systems-an ... 61.article

Image
by keesje, ages ago..


From what I've heard from people at Embraer, it will not be easy to certify a new, high-performance aircraft that has a high wing configuration, mainly for safety reasons.

I think ATR folks might be tempted to stick to their weight and power segment and emphasize the excellent fuel consumption for short trips. Maybe adopting turboprops with a greater number/smaller diameter of propellers can help reduce noise and vibrations. In other words, no drastic changes.
 
avier
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 2:44 pm

As exciting as this project looks, let's not forget Embraer needs to find a partner for this project first.
They aren't going solo on this , as mentioned earlier. And whoever they partner with, might want to change or influence the design too.

I also wonder what markets are they actually targetting. It seems more directed to the North & South American continent.

Embraer commercial aircrafts don't have a very strong presence in Asia, so I wonder how they're going to penetrate this market dominated by ATR's in the regional segment. A large part of ATR's success in Asia is support centres across Asia, along with access to plenty of simulators for pilot training, aircraft spare parts etc.
 
744SPX
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 4:16 pm

keesje wrote:
If this design can cruise at 650-725 km/hr, at considerably lower cost, low noise levels and 90-100 passengers in good comfort, flights up to at least 1000nm should be feasible.



Given that the wing sweep looks similar to the A400M's, I'm guessing at least 725 km/hr.
 
IAHObserver
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 4:54 pm

keesje wrote:
Although the pusher props we saw in past design studies and prototypes provide advantages in terms of congfiguration and weight, these puller ones deal with the noise issue (external and in the cabin). The pusher props are noisy because of disturbed airflow, wake hitting the props. Props in the tail make a big difference in the cabin too.

The price you pay is weight. The weight of the engines and engine cowling is carried by the wings, that are far away from the wings vs wing mounted engines. That takes a lot of structure.

Apart from noise an advantage of the tail configuration is that engines are close together. In 1 engine out situations, the asymetric thrust issue is smaller than with wing mounted engines.

I expect ATR to respond with a stretch, new engines and forward passenger door.

Could this change in design also make it easier to implement a future hybrid powerplant? It seems a lot easier to replace existing podded engines with the future tech and not have to deal with the wing when implementing those upgrades.
 
KlimaBXsst
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 5:13 pm

Image

So in looking at the engine nacelles, it looks as if there has been plenty of potential wind tunnel research and development testing proposals to alleviate engine fuselage attachment point drag, vibration, and noise issues.

I have a feeling this this design may be further along then we know. I am sure a lot of lessons were learned from the CBA-123 Vector. Excellent design to have in the stable with as much system commonality with the prolific Ejets does seem an economically prudent way of going forward with first generation Regional Jet, Q400, and ATR-72 / 42 replacement.
 
SEU
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 5:14 pm

bigb wrote:
DL717 wrote:
avier wrote:
This design makes a lot more sense than the previous one of the engines mounted on a low wing frame. The engines though would need to be light, or this would bring up the issues like that of the CRJ's, i.e also accounting for future hybrid technology.
They should add some kind of wingtip fences, if it helps in the design/efficiency in any way, that'd look so cool.


You throw a blade with that design and it’s over. No thanks.


I was just thinking this......


I did too, but then thought, what's the difference between any other prop plane?
 
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keesje
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 5:14 pm

IAHObserver wrote:
keesje wrote:
Although the pusher props we saw in past design studies and prototypes provide advantages in terms of congfiguration and weight, these puller ones deal with the noise issue (external and in the cabin). The pusher props are noisy because of disturbed airflow, wake hitting the props. Props in the tail make a big difference in the cabin too.

The price you pay is weight. The weight of the engines and engine cowling is carried by the wings, that are far away from the wings vs wing mounted engines. That takes a lot of structure.

Apart from noise an advantage of the tail configuration is that engines are close together. In 1 engine out situations, the asymetric thrust issue is smaller than with wing mounted engines.

I expect ATR to respond with a stretch, new engines and forward passenger door.

Could this change in design also make it easier to implement a future hybrid powerplant? It seems a lot easier to replace existing podded engines with the future tech and not have to deal with the wing when implementing those upgrades.


It seems podded engines & O2 fuel tanks (Airbus) are a complication for center of gravity on such a tailmounted engined configuration. Closer to the wings or in the wings seems preferable.
 
744SPX
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 5:54 pm

The wing and horizontal tailplane look less optimized than in the wing mounted engine version renders. likely not the final design.
 
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ikolkyo
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 5:57 pm

Looks like an E-145 with props and the E1/E2 nose.
 
airlineworker
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 7:32 pm

Has enough advancement been made in the area of prop engines to make this plane a winner? Not exactly a big market to cause engine makers to pour money into a very small market.
 
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Devilfish
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 9:06 pm

Perhaps engine OEMs are seeing big enough future applications for it that they're willing to invest huge sums to develop the technology. CFM's RISE seems to be at the forefront of these advanced studies..... :spin:

Image
https://web.archive.org/web/20210704003 ... k=1vcJ3d70

https://web.archive.org/web/20210629125 ... gen-engine
 
GalaxyFlyer
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 9:16 pm

Nice bit of photoshop engineering, but rear-mounted geared TP and t-tail, both require a lot of structure, looks like a tough design to get balance right.
 
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Devilfish
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 9:25 pm

Well, their design concepts do include 'conventional' wing-mounting.....

Image
https://web.archive.org/web/20210704004 ... k=97oTYEAn
 
AA737-823
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 9:28 pm

You guys are talking like no one has ever figured out how to put engines on the tail of an airplane without crashing it due to imbalance.
I introduce the ERJ, CRJ, 717, 727, DC-9, Fokker jets, Caravelle.......

Also, re: blade out catastrophe mentioned above, You run the same risks with turbofans in the tail, a la 727, MD-11, etc.
Plus, if they go for Dowty-Rotol propeller, blade out won't be an issue. It's their specialty.
Any anyway, when was the last time a modern turboprop had an actual random blade out event? Most are related to prop strike on runway surface, which won't be a concern with rear-mounted, puller-prop engine designs.
 
GalaxyFlyer
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 9:34 pm

Turboprops require gearboxes something the ERJ, CRJ, DC-9, 717, 727, etc had and they’re usually pretty heavy especially for 3,000-4,000 shp engines. It’s never been done but it might work, that’s what engineering is about. The risks of blade off events must be considered for certification, as will other failure modes.

My bet is a conventional wing mounted design because it works.
 
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william
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sat Aug 14, 2021 10:26 pm

Every questioned posted, do we not think Embraer has not asked them before? Embraer has proven they can design planes, lets see what their brilliant engineers come up with.
 
flyinggoat
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sun Aug 15, 2021 1:27 am

I do wonder at what point, if any, it becomes more advantageous to move the engines to the rear for turbofan engines as well? With larger and larger bypass fans and open rotor in the works, at what point does the longer gear weigh more than the extra structure required for tail mounted engines? Would there come a point when rear mounted ultra-high bypass and open rotor engines are more structurally efficient than wing mounted engines?

Part of me wonders if EMB’s move to a rear mounted design was, in part, due to the possibility of using CFM’s open rotor engines as an option? Perhaps, down the road, an open rotor version of this plane could replace the E-Jets.
 
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william
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sun Aug 15, 2021 3:53 am

GalaxyFlyer wrote:
Turboprops require gearboxes something the ERJ, CRJ, DC-9, 717, 727, etc had and they’re usually pretty heavy especially for 3,000-4,000 shp engines. It’s never been done but it might work, that’s what engineering is about. The risks of blade off events must be considered for certification, as will other failure modes.

My bet is a conventional wing mounted design because it works.


The first concepts pics showed the conventional wing mount engines, but the latest show rear placement. That means they have done the blade failure simulations and have made the necessary reinforcements to the tail area. EMB-123 been flying since 1990, Embraer has more real prototype experience than anyone else.
 
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Taxi645
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sun Aug 15, 2021 8:50 am

What about a Beechcraft starship configuration?:

- Engines in the back.
- But with engine weight relieve on the main lifting services.
- No heavy T-tail required.
- No propeller interference with the fuselage.
 
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keesje
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sun Aug 15, 2021 11:12 am

Taxi645 wrote:
What about a Beechcraft starship configuration?:

- Engines in the back.
- But with engine weight relieve on the main lifting services.
- No heavy T-tail required.
- No propeller interference with the fuselage.


Noisy, if pylon or wing wake hits the propeller it creates that irritating sharp sound. Compare fly past youtube's from Starships, Piaggio's with those e.g. similar sized Beech 200's and the difference is clear.

Starship: https://youtu.be/X2tjx3cTG7c
KingAir 200: https://youtu.be/_BKS6XczrnE
 
PowerJet
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sun Aug 15, 2021 1:07 pm

Just a few questions about this design:

How is this better than a jet? In the US, (which I would presume would be EMBs largest marketing pitch), people have seemed to gravitate toward jets, so trying to pitch a propeller plane could be exceedingly difficult,

I seem to remember that the reason aircraft that meet the profile of the DC-9, MD-80 and 727 were designed that way for a specific reason (jetway-less airports? I don't remember exactly) which is more or less a non issue these days. Why put engines back there? How would they keep it quiet in the cabin especially being that the engines would be attached to the fuselage.

EMB has had challenges in the past with designing scope out of an aircraft. I know the E-2 is out of scope with most major US carriers, so wouldn't a propeller plane of a similar size as the E170/175 would be a challenge if they don't lighten it up?

Handsome design though.
 
Nean1
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Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sun Aug 15, 2021 2:29 pm

PowerJet wrote:
Just a few questions about this design:

How is this better than a jet? In the US, (which I would presume would be EMBs largest marketing pitch), people have seemed to gravitate toward jets, so trying to pitch a propeller plane could be exceedingly difficult,

I seem to remember that the reason aircraft that meet the profile of the DC-9, MD-80 and 727 were designed that way for a specific reason (jetway-less airports? I don't remember exactly) which is more or less a non issue these days. Why put engines back there? How would they keep it quiet in the cabin especially being that the engines would be attached to the fuselage.

EMB has had challenges in the past with designing scope out of an aircraft. I know the E-2 is out of scope with most major US carriers, so wouldn't a propeller plane of a similar size as the E170/175 would be a challenge if they don't lighten it up?

Handsome design though.


In a few years, aircraft that comply with Scope Clauses such as the 175E1 or CRJ-900 will no longer be sold, due to new regulations. On the other hand, it seems clear that, despite the merits of the PW1700 turbofan, the excess weight and diameter makes it unfeasible to produce a more capable aircraft than the 175E1.

Embraer says that this TP aircraft allows for fuel savings of around 20%, with a level of comfort equivalent to current regional jets. Speed and cruising will certainly be a little lower, something that probably won't be critical on trips of up to 2 hours.

It is expected that for the same capacity a turboprop will be lighter.
 
PowerJet
Posts: 36
Joined: Tue Sep 03, 2019 6:17 pm

Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sun Aug 15, 2021 2:42 pm

Nean1 wrote:
PowerJet wrote:
Just a few questions about this design:

How is this better than a jet? In the US, (which I would presume would be EMBs largest marketing pitch), people have seemed to gravitate toward jets, so trying to pitch a propeller plane could be exceedingly difficult,

I seem to remember that the reason aircraft that meet the profile of the DC-9, MD-80 and 727 were designed that way for a specific reason (jetway-less airports? I don't remember exactly) which is more or less a non issue these days. Why put engines back there? How would they keep it quiet in the cabin especially being that the engines would be attached to the fuselage.

EMB has had challenges in the past with designing scope out of an aircraft. I know the E-2 is out of scope with most major US carriers, so wouldn't a propeller plane of a similar size as the E170/175 would be a challenge if they don't lighten it up?

Handsome design though.


In a few years, aircraft that comply with Scope Clauses such as the 175E1 or CRJ-900 will no longer be sold, due to new regulations. On the other hand, it seems clear that, despite the merits of the PW1700 turbofan, the excess weight and diameter makes it unfeasible to produce a more capable aircraft than the 175E1.

Embraer says that this TP aircraft allows for fuel savings of around 20%, with a level of comfort equivalent to current regional jets. Speed and cruising will certainly be a little lower, something that probably won't be critical on trips of up to 2 hours.

It is expected that for the same capacity a turboprop will be lighter.


I do get you with that. A few years in the short term seems cool but a few years like...20? I could see a completely new perspective of aircraft propulsion initiatives seeing all the planning happening today. While I do think turboprops are much more fun than jets and would love to see another turboprop prospect, it seems shortsighted on EMB to place a turboprop in the middle of that. I guess time will tell.
 
Nean1
Posts: 580
Joined: Mon May 30, 2016 11:08 pm

Re: Embraer New Turboprop Aircraft News and Discussion Thread

Sun Aug 15, 2021 2:58 pm

PowerJet wrote:
Nean1 wrote:
PowerJet wrote:
Just a few questions about this design:

How is this better than a jet? In the US, (which I would presume would be EMBs largest marketing pitch), people have seemed to gravitate toward jets, so trying to pitch a propeller plane could be exceedingly difficult,

I seem to remember that the reason aircraft that meet the profile of the DC-9, MD-80 and 727 were designed that way for a specific reason (jetway-less airports? I don't remember exactly) which is more or less a non issue these days. Why put engines back there? How would they keep it quiet in the cabin especially being that the engines would be attached to the fuselage.

EMB has had challenges in the past with designing scope out of an aircraft. I know the E-2 is out of scope with most major US carriers, so wouldn't a propeller plane of a similar size as the E170/175 would be a challenge if they don't lighten it up?

Handsome design though.


In a few years, aircraft that comply with Scope Clauses such as the 175E1 or CRJ-900 will no longer be sold, due to new regulations. On the other hand, it seems clear that, despite the merits of the PW1700 turbofan, the excess weight and diameter makes it unfeasible to produce a more capable aircraft than the 175E1.

Embraer says that this TP aircraft allows for fuel savings of around 20%, with a level of comfort equivalent to current regional jets. Speed and cruising will certainly be a little lower, something that probably won't be critical on trips of up to 2 hours.

It is expected that for the same capacity a turboprop will be lighter.


I do get you with that. A few years in the short term seems cool but a few years like...20? I could see a completely new perspective of aircraft propulsion initiatives seeing all the planning happening today. Seems shortsighted on EMB to place a turboprop in the middle of that. I guess time will tell.


I'm certainly not among those who think that in a few years all air technology will be obsolete because of hybrid, electric or hydrogen-powered planes. These technologies simply do not provide the capacity and safety necessary to transport people for significant distances.

As others have said, I understand that it can be the initial step for larger E3 aircraft (>100 passengers) with a level of economy above the potential of PW GTF, technologies that are inspired by the UDF, Open Rotor and Propfan projects.

Embraer has a lot of expertise in commercial jets (E1, E2), TP aircraft (E110, E120), rear-engined aircraft (145, Phenom, Praetor), and even with reinforced T-tails to withstand large variations of in-flight CG (KC-390) ). A not inconsiderable experience.
 
bar1
Posts: 7
Joined: Mon Jun 10, 2019 3:59 pm

Re: Embraer New Turboprop Aircraft News and Discussion Thread

Mon Aug 16, 2021 4:56 am

Taxi645 wrote:
What about a Beechcraft starship configuration?:

- Engines in the back.
- But with engine weight relieve on the main lifting services.
- No heavy T-tail required.
- No propeller interference with the fuselage.


Maybe get away with T-tail by having the horizontal stabilizer in the pylon/engine support?
 
Okcflyer
Posts: 876
Joined: Sat May 23, 2015 11:10 pm

Re: Embraer New Turboprop Aircraft News and Discussion Thread

Mon Aug 16, 2021 12:40 pm

bar1 wrote:
Taxi645 wrote:
What about a Beechcraft starship configuration?:

- Engines in the back.
- But with engine weight relieve on the main lifting services.
- No heavy T-tail required.
- No propeller interference with the fuselage.


Maybe get away with T-tail by having the horizontal stabilizer in the pylon/engine support?


I suspect that, even if it works, it's probably too risky considering this is to be a low technical risk development. I had thought about that too but then realized:

1) During engine failure, one side of the hstab has different air flow than the other, thereby unbalancing downforce and creating a rolling moment.
2) Drag over the stab likely increases from wake turbulence from the props.
3) Due to size of the props, nearly the entire hstab would be in turbulent air flow.
 
Nean1
Posts: 580
Joined: Mon May 30, 2016 11:08 pm

Re: Embraer New Turboprop Aircraft News and Discussion Thread

Mon Aug 16, 2021 1:02 pm

Okcflyer wrote:
bar1 wrote:
Taxi645 wrote:
What about a Beechcraft starship configuration?:

- Engines in the back.
- But with engine weight relieve on the main lifting services.
- No heavy T-tail required.
- No propeller interference with the fuselage.


Maybe get away with T-tail by having the horizontal stabilizer in the pylon/engine support?


I suspect that, even if it works, it's probably too risky considering this is to be a low technical risk development. I had thought about that too but then realized:

1) During engine failure, one side of the hstab has different air flow than the other, thereby unbalancing downforce and creating a rolling moment.
2) Drag over the stab likely increases from wake turbulence from the props.
3) Due to size of the props, nearly the entire hstab would be in turbulent air flow.



I believe that the most convenient thing is that, at cruising speed, the pylon/engine support has neutral lift. And that it is as light and with the least aerodynamic drag as possible.
 
Okcflyer
Posts: 876
Joined: Sat May 23, 2015 11:10 pm

Re: Embraer New Turboprop Aircraft News and Discussion Thread

Mon Aug 16, 2021 1:23 pm

I tend to agree with those who think this design increases structural weight compared to typical t-prop configuration: high wing with engines.

However, depending on the mission profile targeted, lowest weight != lowest fuel burn.

Here are some advantages of the proposed layout i've thought of:

1) Optimized wing: The design allows the wing to be thinner and better optimized aerodynamically. Tprop engines on wings create quite a bit of drag from the prop wash and plyon integration. I believe this hasn't been an area of focus due to relatively short stage lengths and fundamental efficiency advantage tprops have over jets. While there hasn't been much optimization in this area on tprops, in the turbofan space there has been a lot of research has gone into optimum engine/wing/pylon placement. I wager there is a net drag reduction with the props in the back on little engine mounts.
2) Wing-body integration: High wing design creates a major hurdle with body integration. Most classic designs stick the wing above the body, which creates a discontinuity along the top of the fuse. This has pretty high drag impact and is very difficult to optimize. Sticking it through the fuse interferes with cabin space and creates a section without adequate headroom -- not an option. Low wing designs are difficult due to engine placement on wing needing to be high, which is not feasible due to efficiency loss. Low wing with under wing mount engines and using very tall landing gears is an option, but such gear is and mount area is, frankly, unfeasible due to weight using conventional materials, and too-expensive to produce using advanced or rare high performance materials. The proposed layout eliminates all of these concerns; i.e. low wing placement with classical wingbox not affecting cabin space, and standard landing gear to minimize weight/costs.
3) Cabin noise and vibration: As others have alluded to, the cabin noise will be significantly less on this layout compared to classical wing mounted engines. However, I think there is a good chance that cabin vibration is significantly lower as well. This is not something often discussed, but classical tprops produce a lot of vibrations that amplify the perceived noise level. A lot of this is caused by prop wash over the wing. With this design, I think these can be minimized. I will note, the natural frequency will be different due to the placement at the back and they may have to be careful with resonance scenarios.
4) Most tprops use T-tails to keep it out of the prop wash. I don't think that's a big deal here. Hstab will need to be larger, however, due to the shorter distance to wing.

Downsides:
1) Weight: Additional structural weight is required. This may be offset some depending on material selection and operating ceiling. For example, if the mission profile calls for a ceiling of FL35 for storm/mountain routing comfort, the additional hoop stress structure needed by this may already be sufficient to carry the longitude stresses required by the rear mount, so it may not actually end up being much more weight.
2) Runway performance: Rather than tail strike, it looks like the props will touch ground before the tail does. Prop strike is a bigger deal than tail strike, and additional margins will be needed here. I can see runway performance being closer to turbofan type requirements, rather than conventional tprops, which may reduce the addressable market.
3) I'm still not convinced the USA public will accept it, and it's the largest single market.
4) Are there enough synergies with E2 program? Those subsystems are optimized for longer flights and are likely too expensive for this mission profile??
 
Nean1
Posts: 580
Joined: Mon May 30, 2016 11:08 pm

Re: Embraer New Turboprop Aircraft News and Discussion Thread

Mon Aug 16, 2021 5:30 pm

Okcflyer wrote:
I tend to agree with those who think this design increases structural weight compared to typical t-prop configuration: high wing with engines.

However, depending on the mission profile targeted, lowest weight != lowest fuel burn.

Here are some advantages of the proposed layout i've thought of:

1) Optimized wing: The design allows the wing to be thinner and better optimized aerodynamically. Tprop engines on wings create quite a bit of drag from the prop wash and plyon integration. I believe this hasn't been an area of focus due to relatively short stage lengths and fundamental efficiency advantage tprops have over jets. While there hasn't been much optimization in this area on tprops, in the turbofan space there has been a lot of research has gone into optimum engine/wing/pylon placement. I wager there is a net drag reduction with the props in the back on little engine mounts.
2) Wing-body integration: High wing design creates a major hurdle with body integration. Most classic designs stick the wing above the body, which creates a discontinuity along the top of the fuse. This has pretty high drag impact and is very difficult to optimize. Sticking it through the fuse interferes with cabin space and creates a section without adequate headroom -- not an option. Low wing designs are difficult due to engine placement on wing needing to be high, which is not feasible due to efficiency loss. Low wing with under wing mount engines and using very tall landing gears is an option, but such gear is and mount area is, frankly, unfeasible due to weight using conventional materials, and too-expensive to produce using advanced or rare high performance materials. The proposed layout eliminates all of these concerns; i.e. low wing placement with classical wingbox not affecting cabin space, and standard landing gear to minimize weight/costs.
3) Cabin noise and vibration: As others have alluded to, the cabin noise will be significantly less on this layout compared to classical wing mounted engines. However, I think there is a good chance that cabin vibration is significantly lower as well. This is not something often discussed, but classical tprops produce a lot of vibrations that amplify the perceived noise level. A lot of this is caused by prop wash over the wing. With this design, I think these can be minimized. I will note, the natural frequency will be different due to the placement at the back and they may have to be careful with resonance scenarios.
4) Most tprops use T-tails to keep it out of the prop wash. I don't think that's a big deal here. Hstab will need to be larger, however, due to the shorter distance to wing.

Downsides:
1) Weight: Additional structural weight is required. This may be offset some depending on material selection and operating ceiling. For example, if the mission profile calls for a ceiling of FL35 for storm/mountain routing comfort, the additional hoop stress structure needed by this may already be sufficient to carry the longitude stresses required by the rear mount, so it may not actually end up being much more weight.
2) Runway performance: Rather than tail strike, it looks like the props will touch ground before the tail does. Prop strike is a bigger deal than tail strike, and additional margins will be needed here. I can see runway performance being closer to turbofan type requirements, rather than conventional tprops, which may reduce the addressable market.
3) I'm still not convinced the USA public will accept it, and it's the largest single market.
4) Are there enough synergies with E2 program? Those subsystems are optimized for longer flights and are likely too expensive for this mission profile??


The design of the wings seems to be far from conventional. Will it be very thin and have slats? Does the fairing in front of the wings hide fuel tanks?
 
User avatar
aerolimani
Posts: 1460
Joined: Tue Jun 18, 2013 5:46 pm

Re: Embraer New Turboprop Aircraft News and Discussion Thread

Mon Aug 16, 2021 6:19 pm

Okcflyer wrote:
I tend to agree with those who think this design increases structural weight compared to typical t-prop configuration: high wing with engines.

However, depending on the mission profile targeted, lowest weight != lowest fuel burn.

Here are some advantages of the proposed layout i've thought of:

1) Optimized wing: The design allows the wing to be thinner and better optimized aerodynamically. Tprop engines on wings create quite a bit of drag from the prop wash and plyon integration. I believe this hasn't been an area of focus due to relatively short stage lengths and fundamental efficiency advantage tprops have over jets. While there hasn't been much optimization in this area on tprops, in the turbofan space there has been a lot of research has gone into optimum engine/wing/pylon placement. I wager there is a net drag reduction with the props in the back on little engine mounts.
2) Wing-body integration: High wing design creates a major hurdle with body integration. Most classic designs stick the wing above the body, which creates a discontinuity along the top of the fuse. This has pretty high drag impact and is very difficult to optimize. Sticking it through the fuse interferes with cabin space and creates a section without adequate headroom -- not an option. Low wing designs are difficult due to engine placement on wing needing to be high, which is not feasible due to efficiency loss. Low wing with under wing mount engines and using very tall landing gears is an option, but such gear is and mount area is, frankly, unfeasible due to weight using conventional materials, and too-expensive to produce using advanced or rare high performance materials. The proposed layout eliminates all of these concerns; i.e. low wing placement with classical wingbox not affecting cabin space, and standard landing gear to minimize weight/costs.
3) Cabin noise and vibration: As others have alluded to, the cabin noise will be significantly less on this layout compared to classical wing mounted engines. However, I think there is a good chance that cabin vibration is significantly lower as well. This is not something often discussed, but classical tprops produce a lot of vibrations that amplify the perceived noise level. A lot of this is caused by prop wash over the wing. With this design, I think these can be minimized. I will note, the natural frequency will be different due to the placement at the back and they may have to be careful with resonance scenarios.
4) Most tprops use T-tails to keep it out of the prop wash. I don't think that's a big deal here. Hstab will need to be larger, however, due to the shorter distance to wing.

Downsides:
1) Weight: Additional structural weight is required. This may be offset some depending on material selection and operating ceiling. For example, if the mission profile calls for a ceiling of FL35 for storm/mountain routing comfort, the additional hoop stress structure needed by this may already be sufficient to carry the longitude stresses required by the rear mount, so it may not actually end up being much more weight.
2) Runway performance: Rather than tail strike, it looks like the props will touch ground before the tail does. Prop strike is a bigger deal than tail strike, and additional margins will be needed here. I can see runway performance being closer to turbofan type requirements, rather than conventional tprops, which may reduce the addressable market.
3) I'm still not convinced the USA public will accept it, and it's the largest single market.
4) Are there enough synergies with E2 program? Those subsystems are optimized for longer flights and are likely too expensive for this mission profile??

I wonder how much weight savings would exist for a wing and wingbox which do not have to support either engines or landing gear. I could see that being enough to offset weight gains at the rear.

As to TP acceptance in the USA, I could see this design doing better. I feel like the negative connotations are uniformly based around designs with wing-mounted props. It’s partly the snazzy livery Embraer designed in this artistic rendering, but to me the craft has a very modern look to it; very different from a DH8, Q400, B1900, ATR72/42, or almost any other TP in regular commercial US service within the last 40+ years.
 
Okcflyer
Posts: 876
Joined: Sat May 23, 2015 11:10 pm

Re: Embraer New Turboprop Aircraft News and Discussion Thread

Mon Aug 16, 2021 9:36 pm

aerolimani wrote:
Okcflyer wrote:
I tend to agree with those who think this design increases structural weight compared to typical t-prop configuration: high wing with engines.

However, depending on the mission profile targeted, lowest weight != lowest fuel burn.

Here are some advantages of the proposed layout i've thought of:

1) Optimized wing: The design allows the wing to be thinner and better optimized aerodynamically. Tprop engines on wings create quite a bit of drag from the prop wash and plyon integration. I believe this hasn't been an area of focus due to relatively short stage lengths and fundamental efficiency advantage tprops have over jets. While there hasn't been much optimization in this area on tprops, in the turbofan space there has been a lot of research has gone into optimum engine/wing/pylon placement. I wager there is a net drag reduction with the props in the back on little engine mounts.
2) Wing-body integration: High wing design creates a major hurdle with body integration. Most classic designs stick the wing above the body, which creates a discontinuity along the top of the fuse. This has pretty high drag impact and is very difficult to optimize. Sticking it through the fuse interferes with cabin space and creates a section without adequate headroom -- not an option. Low wing designs are difficult due to engine placement on wing needing to be high, which is not feasible due to efficiency loss. Low wing with under wing mount engines and using very tall landing gears is an option, but such gear is and mount area is, frankly, unfeasible due to weight using conventional materials, and too-expensive to produce using advanced or rare high performance materials. The proposed layout eliminates all of these concerns; i.e. low wing placement with classical wingbox not affecting cabin space, and standard landing gear to minimize weight/costs.
3) Cabin noise and vibration: As others have alluded to, the cabin noise will be significantly less on this layout compared to classical wing mounted engines. However, I think there is a good chance that cabin vibration is significantly lower as well. This is not something often discussed, but classical tprops produce a lot of vibrations that amplify the perceived noise level. A lot of this is caused by prop wash over the wing. With this design, I think these can be minimized. I will note, the natural frequency will be different due to the placement at the back and they may have to be careful with resonance scenarios.
4) Most tprops use T-tails to keep it out of the prop wash. I don't think that's a big deal here. Hstab will need to be larger, however, due to the shorter distance to wing.

Downsides:
1) Weight: Additional structural weight is required. This may be offset some depending on material selection and operating ceiling. For example, if the mission profile calls for a ceiling of FL35 for storm/mountain routing comfort, the additional hoop stress structure needed by this may already be sufficient to carry the longitude stresses required by the rear mount, so it may not actually end up being much more weight.
2) Runway performance: Rather than tail strike, it looks like the props will touch ground before the tail does. Prop strike is a bigger deal than tail strike, and additional margins will be needed here. I can see runway performance being closer to turbofan type requirements, rather than conventional tprops, which may reduce the addressable market.
3) I'm still not convinced the USA public will accept it, and it's the largest single market.
4) Are there enough synergies with E2 program? Those subsystems are optimized for longer flights and are likely too expensive for this mission profile??

I wonder how much weight savings would exist for a wing and wingbox which do not have to support either engines or landing gear. I could see that being enough to offset weight gains at the rear.

As to TP acceptance in the USA, I could see this design doing better. I feel like the negative connotations are uniformly based around designs with wing-mounted props. It’s partly the snazzy livery Embraer designed in this artistic rendering, but to me the craft has a very modern look to it; very different from a DH8, Q400, B1900, ATR72/42, or almost any other TP in regular commercial US service within the last 40+ years.


Engines typically reduce the weight of wing spars + wing skin, not increase it. This is because they provide reverse bending relief along the span.

Similar story with the landing gear. The loads from it are high and the lightest place to attach them is in the wingbox. Otherwise, you'll have to carry heavy structure from the wingbox to the mounting point, and that'll be on a moment arm magnifying the force. Further, for center of lift of the wings is near where the center of gravity should be on the ground. The gear cannot be too far forward otherwise it'll tip on it's tail. And any further you move the gear back increases the load on the nose landing gear, further increasing weight and decreasing break ability. I'm confident the gear will fold into the main wing box.This is the only logical way to approach a wheeled landing gear (floats/pontoon's introduce some alternative concepts).

I'm not sure how much the WBF (wing body flaring) is random work by a graphics person doing a mockup vs representative of their actual engineering concepts. WBF has been an area of great research and improvement over the past 20 years.

If this design is representative, they may have found clever low-drag solution to prevent turbulent air from reaching the props (one of the major problems of rear props, especially at some AOA's). This increases drag and noise. Could be one of those "critical enablers" for success of the design concept. Biggest one is the engine/vstab/tailcone integration which someone else indicated previously. If they get that wrong, this thing is DOA. If they get it right, this could become the eureka moment for tprops moving forward.

Regarding the wing: the mock up looks pretty similar to some Cessna's Citation wings. I imagine it'll have good laminar flow characteristics and have a great lift-drag ratio. As I stated earlier, lightest isn't always most efficient, and they may have come across a combination where the drag improvement of the wing more than offsets the structure weight penalty. Classical tprop wings are not highly optimized aerodynamically, and certainly not for fast (ish) cruise speeds. I'm not convinced this thing needs to be Q400 fast, but it cannot be ATR slow and cover 800nm sectors.
 
User avatar
william
Posts: 3557
Joined: Thu Jun 10, 1999 1:31 pm

Re: Embraer New Turboprop Aircraft News and Discussion Thread

Mon Aug 16, 2021 10:01 pm

One of the reasons for moving the props to the back is noise. At least when it does its morning runup it will not be deafening in the cabin. To the non Avgeek it even looks like an RJ. If the fuel efficiency gains are there it will do well in the marketplace.
 
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Kiwirob
Posts: 13684
Joined: Mon Jun 13, 2005 2:16 pm

Re: Embraer New Turboprop Aircraft News and Discussion Thread

Tue Aug 17, 2021 5:26 am

keesje wrote:

I expect ATR to respond with a stretch, new engines and forward passenger door.


You can get them with forward passenger door already, I've been on a Finnair ATR where we loaded through the front door.

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