Search found 132 matches

by CowAnon
Wed Sep 02, 2020 9:40 pm
Forum: Civil Aviation
Topic: Why did the Airbus a340 outsell the MD-11?
Replies: 136
Views: 19140

Re: Why did the Airbus a340 outsell the MD-11?

The Superfan was not everything they made it out to be, it was supposed to be ~7% better than the V2500, which at the time was a point or two better than the CFM56-5A. The wing extension, ~8t MTOW bump, and lower weight of the CFM56-5C, plus the parts commonality, got them to within 1% of the origi...

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by CowAnon
Wed Sep 02, 2020 7:41 pm
Forum: Civil Aviation
Topic: Why did the Airbus a340 outsell the MD-11?
Replies: 136
Views: 19140

Re: Why did the Airbus a340 outsell the MD-11?

2/I think whilst develop engines for 330, engines use can be models grown from 763ER, MD-11 and 747-400, IAE Superfan not being built were a major setback for A340 The Superfan was not everything they made it out to be, it was supposed to be ~7% better than the V2500, which at the time was a point ...

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by CowAnon
Fri Aug 28, 2020 9:17 pm
Forum: Civil Aviation
Topic: Boeing Considers Closing 787 Production in WA
Replies: 160
Views: 24184

Re: Boeing Considers Closing 787 Production in WA

Who does COMAC send the gift basket if the industry stays stagnant that long? It won't. I cannot disclose who, but another Western airframer is studying re-entering the commercial market. So either Airbus and Boeing develop, or the market moves on. "Re-entering the commercial market" == L...

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by CowAnon
Fri Aug 28, 2020 9:06 pm
Forum: Technical/Operations
Topic: Did Boeing ever plan to build a single deck 747?
Replies: 34
Views: 2606

Re: Did Boeing ever plan to build a single deck 747?

The hump is beneficial in several ways. Why was the hump considered a benefit aerodynamically when the 747 was designed, and why is it now considered detrimental? :? What do you mean? The hump is not considered detrimental aerodynamically. The hump was not originally an aerodynamic enhancement. It ...

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by CowAnon
Thu Aug 27, 2020 2:20 am
Forum: Technical/Operations
Topic: Did Boeing ever plan to build a single deck 747?
Replies: 34
Views: 2606

Re: Did Boeing ever plan to build a single deck 747?

Starlionblue wrote:
The hump is beneficial in several ways.

Why was the hump considered a benefit aerodynamically when the 747 was designed, and why is it now considered detrimental? :?

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by CowAnon
Wed Aug 12, 2020 7:15 pm
Forum: Technical/Operations
Topic: Typical MD-82 Cruise Speed
Replies: 23
Views: 2746

Re: Typical MD-82 Cruise Speed

(Deleted)

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by CowAnon
Sun Aug 02, 2020 7:45 pm
Forum: Technical/Operations
Topic: Typical MD-82 Cruise Speed
Replies: 23
Views: 2746

Re: Typical MD-82 Cruise Speed

The McDonnell Douglas DC-9 Super 80 Configuration Guide lists long-range cruise at Mach 0.76 and high-speed cruise at Mach 0.80 for the MD-81 and MD-82. https://ia803004.us.archive.org/BookReader/BookReaderImages.php?zip=/20/items/dc9super80configurationguide/DC-9%20Super%2080%20Configuration%20Gui...

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by CowAnon
Thu Jul 30, 2020 10:22 pm
Forum: Technical/Operations
Topic: A400M / TP400 (down between the) engines questions
Replies: 11
Views: 2981

Re: A400M / TP400 (down between the) engines questions

Down-Between-Engines (DBE) ... Thanks for the explanation! While I'm not sure about the exact chronology, I remember that some significant delay in engine development was caused by mismanagement/differing views about whether the FADEC software was to be designed by military or civilian standards. I...

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by CowAnon
Wed Jul 29, 2020 9:19 am
Forum: Technical/Operations
Topic: A400M / TP400 (down between the) engines questions
Replies: 11
Views: 2981

Re: A400M / TP400 (down between the) engines questions

Thanks for your input. I was thinking about DBE vs. UBE because of the benefit of air flow over the wing, which I asked about in an older thread . Can someone explain why DBE allows the horizontal stabilizer to be shrunk? I get why the vertical stabilizer can be smaller, since having 4 turboprops tu...

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by CowAnon
Tue Jul 28, 2020 12:09 am
Forum: Travel, Polls & Preferences
Topic: Why was the 747-500 cancelled?
Replies: 40
Views: 15378

Re: Why was the 747-500 cancelled?

The 747-500, 747-600, and 767-400ERX would've all shared an engine that did not come to fruition, and were all subsequently cancelled. Which engine was that? A Trent derivative. I believe it was to be designated the Trent 600. Because we are talking about undeveloped variants, the waters are somewh...

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by CowAnon
Thu Jun 25, 2020 8:00 pm
Forum: Civil Aviation
Topic: Embraer's has projects for a new turboprop plane [June/2020]
Replies: 127
Views: 18558

Re: Embraer's has projects for a new turboprop plane [June/2020]

https://leehamnews.com/2016/03/24/pw-ca ... certainty/
-->

It was shown in this thread before, but the post must've been deleted.

I think the image is from a 2016 Leeham News article:
https://leehamnews.com/2016/03/24/pw-ca ... certainty/

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by CowAnon
Thu Jun 25, 2020 8:11 am
Forum: Civil Aviation
Topic: Embraer's has projects for a new turboprop plane [June/2020]
Replies: 127
Views: 18558

Re: Embraer's has projects for a new turboprop plane [June/2020]

That 6000 shp on the slide is per engine for the NGRT engine. The Q400 has 5000 shp so it is safe to say the Embraer turboprop will be much bigger than the ATR72 and Q400. The NGRT design starts at 4500 shp with growth all the way up to 8000 shp. Embraer turning E-jet into a turboprop will be fairl...

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by CowAnon
Thu Jun 25, 2020 8:07 am
Forum: Technical/Operations
Topic: A400M / TP400 (down between the) engines questions
Replies: 11
Views: 2981

Re: A400M / TP400 (down between the) engines questions

1.Is the additional lift just caused by the adjacent propellers' tips moving in the same direction, or does the benefit occur specifically because the flow is downward below the wing? If the between-engine tips were simultaneously moving the air upward above the wing instead, wouldn't there be a si...

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by CowAnon
Mon Jun 22, 2020 6:58 pm
Forum: Technical/Operations
Topic: A400M / TP400 (down between the) engines questions
Replies: 11
Views: 2981

A400M / TP400 (down between the) engines questions

From ANALYSIS: A400M Grizzly bares all , (FlightGlobal, June 7, 2013): DOWN BETWEEN THE ENGINES For the A400M Airbus has developed a unique down-between-the-engines (DBE) scheme for propeller rotation direction. Engines 1 and 3 rotate clockwise, while 2 and 4 have an idler gear installed that gives ...

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by CowAnon
Sat Jun 13, 2020 5:16 am
Forum: Civil Aviation
Topic: Embraer's has projects for a new turboprop plane [June/2020]
Replies: 127
Views: 18558

Re: Embraer's has projects for a new turboprop plane [June/2020]

The Antonov An-70 entered service in 2015 for the Ukrainian armed forces. Whether it's faster than the A400M depends on which source you find. (One article says it can go up to Mach 0.8.) Unfortunately there's only one of them, and they can't build more until Ukraine either settles its differences w...

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by CowAnon
Wed Jun 10, 2020 1:14 am
Forum: Non-Aviation
Topic: The New River Gorge Bridge
Replies: 21
Views: 1797

Re: The New River Gorge Bridge

ArchGuy1 wrote:
Have you personally seen the New River Gorge Bridge?
No, I've never been to West Virginia, so I've only seen the pictures.

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by CowAnon
Tue Jun 09, 2020 9:21 pm
Forum: Civil Aviation
Topic: Embraer's has projects for a new turboprop plane [June/2020]
Replies: 127
Views: 18558

Re: Embraer's has projects for a new turboprop plane [June/2020]

I think Embraer has witnessed that if you go head to head with Airbus or Boeing you better have a lot of time, political back-up and money. https://i191.photobucket.com/albums/z160/keesje_pics/Turbolineraircraftturboprop-1.jpg?t=1208899184 keesje So far Embraer has been smart enough to stay away th...

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by CowAnon
Tue Jun 09, 2020 7:41 am
Forum: Technical/Operations
Topic: Supersonic Engine effeciency
Replies: 15
Views: 3220

Re: Supersonic Engine effeciency

I've never ever seen a speed normalizes SFC. Is that even a thing? If a jet engine accelerates from 200 mph to 400 mph should I expect it's SFC to halve? If it goes from 1 mph to 0 mph should it's SFC go to infinity? BTW, I totally get that work = thrust * speed. SFC stays (approximately*) constant...

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by CowAnon
Tue Jun 09, 2020 7:07 am
Forum: Non-Aviation
Topic: The New River Gorge Bridge
Replies: 21
Views: 1797

Re: The New River Gorge Bridge

The New River Gorge bridge is much more impressive. https://upload.wikimedia.org/wikipedia/commons/thumb/1/11/New_River_Gorge_Bridge.jpg/1280px-New_River_Gorge_Bridge.jpg The Marquam bridge is the ugliest bridge in Portland. It's not an arch, either. https://live.staticflickr.com/2211/2501776216_217...

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by CowAnon
Tue Jun 09, 2020 3:08 am
Forum: Non-Aviation
Topic: The New River Gorge Bridge
Replies: 21
Views: 1797

Re: The New River Gorge Bridge

https://en.wikipedia.org/wiki/List_of_longest_arch_bridge_spans I really like arch bridges. Unfortunately most of the new bridges seem to be of the cable-stayed style, which look okay, but I don't want all bridges to look like that. Here's the 2nd longest double-decker arch bridge in the world: http...

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by CowAnon
Sat May 30, 2020 11:48 pm
Forum: Civil Aviation
Topic: Building airports at the sea
Replies: 20
Views: 5582

Re: Building airports at the sea

Whenever somebody mentions putting an airport on the water, I always think about Tetrahedron City: https://66.media.tumblr.com/tumblr_m53wy3TLte1r064gzo1_500.jpg (From the San Francisco Museum of Modern Art's Tumblr page .) Also, from The Lost Inventions of Buckminster Fuller (Part 3 of 3) : Tetrahe...

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by CowAnon
Wed May 27, 2020 3:07 am
Forum: Civil Aviation
Topic: Development paths for new scope compliant aircraft.
Replies: 355
Views: 16756

Re: Development paths for new scope compliant aircraft.

The highest efficiently potential is with unducted fan engines. I think this only works with tail mounted engines. I wonder if US public will view these engines as unsafe, like turboprop engines. Are unduucted fans lighter per lb. of thrust produced? It seems logical that they world be without the ...

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by CowAnon
Sat May 16, 2020 9:39 pm
Forum: Technical/Operations
Topic: Transonic truss the solution for regional aircraft?
Replies: 22
Views: 3612

Re: Transonic truss the solution for regional aircraft?

Yes, financing will be a huge problem, and the 150-180 seat airplane market should be targeted before the sub-76-seat market. Though it's unlikely, it's not impossible that a developing/developed country starts throwing money into aircraft development. Same thing with billionaires, though currently ...

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by CowAnon
Fri May 15, 2020 8:36 pm
Forum: Technical/Operations
Topic: Transonic truss the solution for regional aircraft?
Replies: 22
Views: 3612

Re: Transonic truss the solution for regional aircraft?

(I'm no aeronautical engineer, but I'll add my thoughts anyway.) PICTURE: Boeing unveils trussed wing capable of jet speeds (FlightGlobal, 9 January 2019) Boeing achieved the improvement by tweaking the truss and the wing sweep. It has estimated such wings can reduce an aircraft’s fuel burn by 8-10...

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by CowAnon
Mon May 04, 2020 6:36 pm
Forum: Civil Aviation
Topic: Airbus announces € 1.36 billion net loss
Replies: 89
Views: 18552

Re: Airbus announces € 1.36 billion net loss

The engine is the result of trying to get a takeoff distance < 1000 m while also achieving M .72 at FL400 with 36 tons payload. The speed basically requires a turbofan while the STOL and rough field capability very much prefer a turboprop. So you get a very large unducted fan, sort of. And the gear...

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by CowAnon
Sun Apr 12, 2020 3:02 am
Forum: Technical/Operations
Topic: How difficult it is to upscaled GTF
Replies: 30
Views: 3441

Re: How difficult it is to upscaled GTF

Alternate link, without the paywall (I think): https://www.bloombergquint.com/business/airbus-reveals-plans-for-all-new-narrow-body-re-engined-a350. Just repeating what I've read on these boards, but it's supposedly much tougher to upscale a geared turbofan than to downscale one. The gearbox effici...

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by CowAnon
Sun Apr 12, 2020 2:46 am
Forum: Technical/Operations
Topic: How difficult it is to upscaled GTF
Replies: 30
Views: 3441

Re: How difficult it is to upscaled GTF

Yeah, drag and weight go up, but propoulsive efficiency and thermodynamic efficiency improve. Think of it this way: some lines go up and right, others go down and right. You add them all together, and get a U-shape, then pick the bottom of the U. This is obviously a slight simplification, but you g...

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by CowAnon
Tue Apr 07, 2020 10:55 pm
Forum: Technical/Operations
Topic: NMA/MOM/797 variant performance analysis
Replies: 151
Views: 13616

Re: NMA/MOM/797 variant performance analysis

@Fred: I got confused. Let me correct it for you. Embraer had to same situation, wanting to benefit from the high BPR Pratt GTF's they redesined the wing, using a seagull configuration. A radical, expensive modification from the E190 E1. https://www.aerotime.aero/upload/files/4-Embraer_E-Jet_front_...

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by CowAnon
Tue Apr 07, 2020 10:22 pm
Forum: Technical/Operations
Topic: How difficult it is to upscaled GTF
Replies: 30
Views: 3441

Re: How difficult it is to upscaled GTF

Sokes wrote:
If bypass ratios are increasing, isn't the advantage for the slower A330 more than for the faster B787?

Larger turbofan/cowling diameters don't require a reduction in cruise speed, so there's no further advantage or disadvantage for slower planes or faster planes.

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by CowAnon
Mon Mar 30, 2020 10:31 pm
Forum: Technical/Operations
Topic: How difficult it is to upscaled GTF
Replies: 30
Views: 3441

Re: How difficult it is to upscaled GTF

You also have to wonder about PW's level of commitment to a widebody GTF. When the current UTC CEO took over in 2014, he said they weren't going to create a new widebody engine. (UTC's merger with Raytheon closes on Friday, but the UTC guy will still be in charge.) PW sort of outlined an engine road...

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by CowAnon
Thu Mar 26, 2020 8:41 pm
Forum: Technical/Operations
Topic: How difficult it is to upscaled GTF
Replies: 30
Views: 3441

Re: How difficult it is to upscaled GTF

Alternate link, without the paywall (I think): https://www.bloombergquint.com/business/airbus-reveals-plans-for-all-new-narrow-body-re-engined-a350. Just repeating what I've read on these boards, but it's supposedly much tougher to upscale a geared turbofan than to downscale one. The gearbox efficie...

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by CowAnon
Tue Mar 10, 2020 5:09 am
Forum: Civil Aviation
Topic: MC-21 Development Thread
Replies: 521
Views: 149944

Re: MC-21 Development Thread

CFRP wing spar enables thinner wing with lower critical Mach number. Entirely realistic Do we have any other sources for the MC-21 using a higher cruise speed than 320/737? I would have expected them to prefer a lighter wing to a faster. A Russian newspaper article ( English translation ) from June...

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by CowAnon
Wed Mar 04, 2020 8:36 am
Forum: Technical/Operations
Topic: (Hypothetical) Water injection on high-bypass engine
Replies: 34
Views: 4467

Re: (Hypothetical) Water injection on high-bypass engine

...The designers considered using water injection with the water condensate from the exhaust: https://www.youtube.com/watch?v=cThIbDONerI http://www.ekip-aviation-concern.com/eng-b/1.shtml ... Here's a little more about the water/fuel mixture mentioned in the video (aquazine): http://www.oilru.com/...

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by CowAnon
Tue Mar 03, 2020 8:40 pm
Forum: Technical/Operations
Topic: (Hypothetical) Water injection on high-bypass engine
Replies: 34
Views: 4467

Re: (Hypothetical) Water injection on high-bypass engine

No, the ones done in the past were just less sophisticated, it is possible to do a water injection system with little or no smoke and overall performance improvements. Check this out: https://mdao.grc.nasa.gov/publications/SAE_H2O_Paper_7_20_04.pdf Thanks, that was an informative article. However, ...

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by CowAnon
Tue Feb 25, 2020 1:10 am
Forum: Travel, Polls & Preferences
Topic: Past possible orders
Replies: 30
Views: 1989

Re: Past possible orders

Back in the mid-late 1970's United had plans to order the proposed, Boeing 727-300. This was to have a lengthened fuselage to accomodate the same number of passengers (189) as the 707-300. It was to have a strengthened landing gear, higher fuel capacity, some aerodynamic tweaks and replacement of t...

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by CowAnon
Sat Feb 22, 2020 12:12 am
Forum: Civil Aviation
Topic: Will there ever been a new greenfield major airport in the USA?
Replies: 144
Views: 14760

Re: Will there ever been a new greenfield major airport in the USA?

Here's an idea sure to be unpopular here (and for my career)... aviation is an inherently dated concept ripe for technological replacement. Hyperloop, or some iteration, stands to make much of commercial air travel obsolete. Short haul flights between major markets will disappear. What remains of a...

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by CowAnon
Thu Feb 20, 2020 11:37 pm
Forum: Civil Aviation
Topic: MC-21 Development Thread
Replies: 521
Views: 149944

Re: MC-21 Development Thread

Found some interesting comparisons of the MC21 done by AFL against the A and B narrowbodies in their fleet. If this bird is reliable and gets a good support network it will give them a run for their money. MTOW, Seats, Avg. Fuel in kg/h, Fuel in grams per ASK https://cdn.aviaforum.ru/data/attachmen...

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by CowAnon
Thu Feb 20, 2020 1:47 am
Forum: Technical/Operations
Topic: (Hypothetical) Water injection on high-bypass engine
Replies: 34
Views: 4467

Re: (Hypothetical) Water injection on high-bypass engine

No, the ones done in the past were just less sophisticated, it is possible to do a water injection system with little or no smoke and overall performance improvements. Check this out: https://mdao.grc.nasa.gov/publications/SAE_H2O_Paper_7_20_04.pdf Thanks, that was an informative article. However, ...

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by CowAnon
Tue Feb 18, 2020 8:11 pm
Forum: Technical/Operations
Topic: NMA/MOM/797 variant performance analysis
Replies: 151
Views: 13616

Re: NMA/MOM/797 variant performance analysis

Really interesting stuff here, just want to ask a couple of things: SFC has been set to 0.49 in all scenarios, this is obviously a fuel consumption/thrust figure of some sort but how does it compare to other contemporary A/C? (A320neo/B787/A350/777X et al) From PD-14: New-generation engine for MC-2...

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by CowAnon
Tue Feb 18, 2020 7:43 pm
Forum: Technical/Operations
Topic: (Hypothetical) Water injection on high-bypass engine
Replies: 34
Views: 4467

Re: (Hypothetical) Water injection on high-bypass engine

If a water-injection system were to be installed on an aircraft high-bypass turbofan, where would the injectors be placed? My guess is probably in the core, just after the low-pressure turbine, or in the bypass duct. Probably not injecting it into the combustion chamber, as cooling the flame would ...

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by CowAnon
Mon Feb 17, 2020 2:24 am
Forum: Civil Aviation
Topic: Help identifying this aircraft?
Replies: 17
Views: 4919

Re: What is this?

i found this odd pic on the internet. The caption says its a Boeing 7J7 1980,but i don't think that's what it is. Its pretty slick looking and i wounder if that tail would work.9291452040_d6387bf761_n.jpg It looks to me that you could take the 787 noise and flight deck on a narrow fuselage like a 1...

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by CowAnon
Wed Feb 12, 2020 9:00 pm
Forum: Site Related
Topic: Linking to news from a thread post
Replies: 0
Views: 1010

Linking to news from a thread post

Can you implement a feature so that when someone enters text like this within a thread posting: [newsid]123456[/newsid] The renderer finds the particular news item from within the a.net news feed (https://www.airliners.net/aviation-news) and displays the news item's title, source, and post time? Per...

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by CowAnon
Wed Feb 12, 2020 8:22 pm
Forum: Technical/Operations
Topic: Big engines planes (2030+) - how will look like?
Replies: 25
Views: 9140

Re: Big engines planes (2030+) - how will look like?

A Romanian flying saucer called ADIFO made headlines last year. It can supposedly fly at supersonic speeds. https://newatlas.com/adifo-flying-saucer-romanian/58999/ Airbus revealed its MAVERIC blended wing body concept yesterday. https://www.cnn.com/travel/article/airbus-blended-wing-maveric/index.h...

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by CowAnon
Thu Jan 23, 2020 7:18 pm
Forum: Civil Aviation
Topic: A clean-sheet 50-90 pax Turboprop by Boeing Brasil Commercial-Embraer. Disruptive technologies needed ?
Replies: 120
Views: 15028

Re: A clean-sheet 50-90 pax Turboprop by Boeing Brasil Commercial-Embraer. Disruptive technologies needed ?

Leeham News also wrote recently about the Unducted Single Fan (USF), which GE and Leonardo are working on for the EU Clean Sky program. The USF has coaxial dual propellers like the GE's UDF, but the back propeller doesn't rotate - it just varies its pitch to capture the swirl energy from the front p...

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by CowAnon
Thu Jan 02, 2020 5:32 am
Forum: Civil Aviation
Topic: Il-114-300 Prototype
Replies: 33
Views: 7694

Re: Il-114-300 Prototype

Specs are here: http://www.ilyushin.org/en/aircrafts/projects/6292/ https://www.ainonline.com/aviation-news/air-transport/2014-09-16/russia-looks-resurrect-il-114 From the article: The Ilyushin’s empty equipped weight, at 16 tons, totals 3 tons more than that of the ATR 72-600; the Franco-Italian ai...

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by CowAnon
Sat Dec 21, 2019 7:34 am
Forum: Travel, Polls & Preferences
Topic: DC-9 Family What-Ifs
Replies: 19
Views: 3414

Re: DC-9 Family What-Ifs

As mentioned, the MD-88 flew after the MD-87 and before the MD-90. It was the same size as the MD-81/82/83, but with an upgraded cockpit and other small changes. Strangely enough, McDonnell Douglas offered a different MD-88 in early 1984 , which specified a 57-inch stretch and V2500 engines. The pro...

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by CowAnon
Mon Dec 09, 2019 1:19 am
Forum: Technical/Operations
Topic: The math behind twins.
Replies: 36
Views: 4357

Re: The math behind twins.

For starters, I am not questioning the math, that's been settled by people who are much more knowledgeable than myself. I am just trying to understand it. … For a twin, each engine needs to be powerful enough to operate the aircraft should the other fail, at the most vulnerable point in the flight....

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by CowAnon
Mon Dec 09, 2019 12:20 am
Forum: Travel, Polls & Preferences
Topic: Should Boeing have increased the range of the 717 instead of developing the MAX?
Replies: 24
Views: 1312

Re: Should Boeing have increased the range of the 717 instead of developing the MAX?

With the newest engines, could the 717 be stretched to approach the seating capacity of the MAX-8? There were at least 3 proposals from the 1980s: ⋅  MD-89: A 152-inch (12.7-foot) proposed stretch of the MD-80 using the V2500 and seating 173 passengers: https://www.flightglobal.com/Flight...

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by CowAnon
Mon Dec 02, 2019 9:02 am
Forum: Travel, Polls & Preferences
Topic: 8 hour layover tonight at midnight. Any ideas?
Replies: 7
Views: 911

Re: 8 hour layover tonight at midnight. Any ideas?

It's been a few years since I've visited Las Vegas, but you should probably stay away from the strip if you want a quiet place to sleep. And downtown, for that matter. If you just want to kill some time in a casino, Luxor's probably okay, but you'll also find lower minimums and maybe better odds off...

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