Airbus A320 / Boeing 737 successors, new engine technology seems crucial

[keesje]

The Boeing 737 has been around for 40 years and has seen major upgrades in the mid eighties and late nineties. The A320 also has passed 20 yrs. Both Airbus and Boeing indicate they don’t see the need for new narrow body aircraft being developed before 2020 earliest. :zzz:

Question is what the airlines will think if oil goes through the roof again. Who will buy Boeing 737/A320's from 2017 for use until 2042? Is it still a good investment? :confused: Public & government pressure to reduce levels of green house gas emissions are also growing.

Airlines like AF/KL, American, Easyjet and Southwest publicly said they want something better ASAP, not from 2020 :=. On top of that competition is pushing from below. New variants of the new 5 abreast Cseries, Superjets, ARJ's and probably new Embraers will push the shorter 737 and A320 variants out of the <150 seats segment.

the major discussion in the industry seems to be on engine technology. Both CFM and Pratt are developing new technology higher bypass engines, the LEAPX and the Geared Turbo Fan (GTF). Both these engines could fit under the wings of A320 and 737 (though with considerable modifications). Those engines promise fuel consumption reduction of around 15%. :D

However a further 10% improvement could be achieved by introducing counter rotating open rotors (CROR) as shown on GE stand at the Paris airshow (CFM LEAPX prototype in front). :ok:

http://i191.photobucket.com/albums/z160/keesje_pics/OPENROTOR-26PCT.jpg?t=1247751620

The CROR technology was tested in the late eighties by GE and PW. However complications (noise, hot gear boxes, vibrations) came up, fuel prices went down and both projects were shelved :ouch:.

Until last year. Fuel prices got sky high. Projects were resurrected, road maps made for implementing new technology. Even after fuel prices went down and the economy collapsed R&D projects move on at GE/Safran and Rolls Royce. R&D seems to be focussing on topics like blade containment, noise reduction and aircraft configurations.

This recent artist impression can be found at http://www.nlr.nl/ (http://www.nlr.nl/), an old R&D instute that does CROR research :cool:

http://www.nlr.nl/eCache/DEF/12/623.jpg
Source : http://www.nlr.nl/smartsite.dws?id=12618 (http://www.nlr.nl/smartsite.dws?id=12618)


It seems both Rolls Royce and GE/Safran (CFM) are betting on two horses for now. Questions are the importance of an additional 10% fuel reduction, can rotor noise be reduced, how to handle gooses and what will the oil prices do for the next 30 yrs..

In the end it's probably the market / airlines that will determine the ambitions of the aircraft manufacturers..

[Dit]

My opinion is that Boeing and Airbus have no need to rush into this, they have the two best selling single aisle aircraftin the industry, let someone else test the technology, then work out their mistakes and produce an airaft that inproves on it. Thus their estimate of 2020ish.

[keesje]

Dit : My opinion is that Boeing and Airbus have no need to rush into this, they have the two best selling single aisle aircraftin the industry, let someone else test the technology, then work out their mistakes and produce an airaft that inproves on it. Thus their estimate of 2020ish.
I think news about configurations for 737/A30X is kept closely secret by Airbus and Boeing. Some details are published:
Airbus is exploring novel aircraft configurations in a wind-tunnel facility, says a company official. Because the A30X concepts differ markedly from traditional Airbus designs, extensive evaluations have to be performed, he adds.
Link to Aviation week article: Airbus Refines A30X Design | AVIATION WEEK (http://www.aviationweek.com/aw/generic/story_generic.jsp?channel=awst&id=news/aw020909p3.xml&headline=Airbus%20Refines%20A30X%20Design)

While open-rotor airliner configurations have been studied for many years, there are questions about likely airworthiness rules in areas such as engine layout and blade containment.
Link to flightglobal article: Airbus links with engine makers to seek clarity from authorities on open rotor airworthiness require (http://www.flightglobal.com/articles/2009/05/21/326827/airbus-links-with-engine-makers-to-seek-clarity-from-authorities-on-open-rotor-airworthiness.html)

http://www.flightglobal.com/assets/getAsset.aspx?ItemID=29115

[lomapaseo]

Well from just the looks of the artist renditions the most unique airworthiness considerations appear to be blade loss and birds.

The blade loss is more than just containment, it also considers imbalance and mount loads as well as windmill issues.

Forget about those big blades and birds and look to the core engine itself for any issues on bird ingestion..

It seems to me that the blade containment issue can be addressed at the aircraft level under it's minimization rule with a little bit of shielding and moving stuff out of harms way (don't ask about today's props:)

[Graybeard]

Airplane design depends on engine availability, as Lockheed was reminded early in the L-1011 program. The second consideration is where to put the landing gear. All other compromises follow.

I was SLF for over 3 hours in a Horizon CRJ yesterday, and that size tube won't replace the 737/320. Horizon long term plans reportedly include dumping the CRJ in favor of more Dash 8-400, which burn a third less fuel.

GB

[keesje]

Well from just the looks of the artist renditions the most unique airworthiness considerations appear to be blade loss and birds.

The blade loss is more than just containment, it also considers imbalance and mount loads as well as windmill issues.

Forget about those big blades and birds and look to the core engine itself for any issues on bird ingestion..

It seems to me that the blade containment issue can be addressed at the aircraft level under it's minimization rule with a little bit of shielding and moving stuff out of harms way (don't ask about today's propshttp://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/smile.gif


I think that's why the artist impression in the first drawing is different then the second older one. You don't want a failing #1 taking out #2 or the other way around. The risk of 1 engine failing is bigger when you have two.. Ref. the flightglobal link I provided in post #3..

[lomapaseo]

The risk of 1 engine failing is bigger when you have two.. Ref. the flightglobal link I provided in post #3..

I could find no such reference:confused:

could you elaborate?

[bjornhall]

Bit of thread drift to the slightly smaller segment...

What about a 100 seat turboprop? It would not involve any new airworthiness issues, and would cut fuel consumption dramatically compared to the jets. As we know, on many short haul trips the time advantage of jet speeds is negligible.

Of course, someone has to come up with the engine, and someone equally brave would have to build the plane...

[Graybeard]

What about a 100 seat turboprop?

It's been around since 1954: the C-130.
Or maybe the Lockheed Electra.

[keesje]

Quote:
The risk of 1 engine failing is bigger when you have two.. Ref. the flightglobal link I provided in post #3..
I could find no such referencehttp://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/confused.gif

could you elaborate?


lomapaseo, from what I understand the flightglobal article is about blade containment and aircraft configurations. Airbus and Boeing have to have guidelines as what is certifyable and what is not. Having something inbetween the engines removes some certification concerns.

Bit of thread drift to the slightly smaller segment...


Bjornhall, could be a start. As you say speed is less important on regional flights. A CROR is significantly faster / more complex then a conventional prop. I believe ATR is looking into a bigger turboprop up to 100 seats. They call it the "-900". ATR refers to new turboprop study as '-900' (http://www.flightglobal.com/articles/2008/07/09/225165/atr-refers-to-new-turboprop-study-as-900.html)

I understand Bombardier was also looking at a bigger prop, although I wonder how much further a Q400 could be stretched and they probably have there hands/budgets tied to the Cseries.