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Blackbird
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If You Could Design A Commercial Jet...

Fri Mar 23, 2007 5:08 am

How would you design it?
 
flipdewaf
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RE: If You Could Design A Commercial Jet...

Fri Mar 23, 2007 5:11 am

WOW! thats a big question. multibillion dollar bank loan?

Fred
 
futurecaptain
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RE: If You Could Design A Commercial Jet...

Fri Mar 23, 2007 5:39 am

On a Computer???
With that million dollar loan.
 
Blackbird
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RE: If You Could Design A Commercial Jet...

Fri Mar 23, 2007 5:50 am

You'd need a billion dollar bank loan these days!

Andrea Kent
 
dc9northwest
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RE: If You Could Design A Commercial Jet...

Fri Mar 23, 2007 6:45 am

Efficient
Spacious
Comfortable


and... On Time...  Smile
 
NWADC9
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RE: If You Could Design A Commercial Jet...

Fri Mar 23, 2007 12:10 pm

Needs JT8D's. Just design a plane around the JT8D, and I'll be happy Big grin
 
ZBBYLW
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RE: If You Could Design A Commercial Jet...

Fri Mar 23, 2007 1:25 pm

Personally I would much rather design something like a turbo prop. Create a new touch a/c something like a DHC-6 would be what I would like to design. Either that or something like a line of A/C like VANS. Sorry no jet a/c but I have put much thought into this so I thought I would pipe up.
 
TSS
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RE: If You Could Design A Commercial Jet...

Fri Mar 23, 2007 1:27 pm

Take an MD-80 tube, build it in modern composites, outfit it with state of the art wings and hang modern hi-efficiency, hi-bypass turbofans underneath those wings, put a conventional tail assembly on it, outfit it with a modern flight deck and state of the art IFE, and make sure it'll be easy to spin off longer and shorter versions of it as needed by various carriers.
 
TSS
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RE: If You Could Design A Commercial Jet...

Sat Mar 24, 2007 10:50 am

Since my practical side seems to have if not killed this thread stone-dead at least made it stall, I'll try to be a bit more adventurous:

Why not a scaled-up, jet-engined aircraft based on the design principles of a Beechcraft Starship?

Seating for a hundred pax or so, and engines mounted on pylons a la Honda Jet for less disrupted airflow over the wings. It would have to have winglet-style rudders and forward canards, of course.
 
flipdewaf
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RE: If You Could Design A Commercial Jet...

Sat Mar 24, 2007 10:58 am

i would go about trying to utilise materials that could change shape depending on the electrical current, this could make for much more efficient aerofoils for different parts of the flight.

Fred
 
GAIsweetGAI
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RE: If You Could Design A Commercial Jet...

Sun Mar 25, 2007 12:13 am

Step 1: get
Next: design the A/C.

Jet: a widebody biplane with its engines between the wings and without the traditional empennage.
Or a revamped MD80 or 757.

Turboprop: something in the lines of the DHC-6/7/8.

Finally: build 2 airframes and keep them for my own personal use. (my Precious...)


Oh, and I forgot: go through the aeronautical engineering courses is step 0.5 or 1.5.

[Edited 2007-03-24 17:13:39]
 
N231YE
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RE: If You Could Design A Commercial Jet...

Sun Mar 25, 2007 11:21 pm

Quoting NWADC9 (Reply 5):

Agreed.

My airplane:

...one with 10 gas-guzzling, screaming, smoking, water-injected TURBOJETs  smile 

I think I'd take the Boeing 717, stretch it and widen it to 3x3 seating, and give it a "787-style" interior. That would be my dream airplane.

I'd also love to see commuter turboprops like this, only bigger:


View Large View Medium
Click here for bigger photo!

Photo © Derek Ferguson

 
Blackbird
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RE: If You Could Design A Commercial Jet...

Mon Mar 26, 2007 2:34 pm

I'd make a three-engined double-decker BWB with an 800 person capacity like McDonnell Douglas' design conceived of awhile ago...


I would have modified the design to make use of new advances in aerodynamics in some of Boeing concepts, and in other studies (involving better blending the cockpit area to the rest of the centerbody and altering the thicknesses and such potentially, which would allow cruise speeds to increase to Mach 0.88 to Mach 0.90, and utilized some of the latest composites to allow for the lightest weight possible, possibly including a type of shear-thickening fluid (Read More Here: http://www.weaponsblog.org/entry/she...-liquid-armor-to-protect-soldiers/ ) which using a liquid with nano particles in them can become extremely hard when subjected to a certain amount of stress. Otherwise, the design would be more or less the same.

Overall, the baseline design for the airplane would be around 160-feet in length, with a nearly 290-foot wingspan, and a vertical height slightly under 41-feet. To allow for operation within the eighty meter ICAO box, the plane would feature wings that would fold upward for taxiing and parking, and would lower into locked position for flight. The cockpit area, which like all planes is up front and is where the pilots sit. Like most modern airliners, it would feature a crew of two, and provision for two or three jump-seats. To provide safety against terrorists, I would add an interesting feature -- a bathroom inside the cockpit area so the crew never need to leave the confines of their cockpit. Behind the cockpit-bullet is the rest of the centerbody where all the passengers are located, all in all there are five parallel cabins each with seats, overhead luggage pins and flip-out flat-screen TV's which connect to sensors on various parts of the airplane to allow most passengers a view of what's going on outside the plane, the system with the press of a button can display an artificial horizon and a series of arrows which helps with orientation, particularly for passengers on the outboard areas where the plane would seem to just lift up and the other side would seem to fall away... Each deck features six exits on each deck located on the front of the centerbody, and two large ramps on each deck located rearwards for evacuation. Outboard of the passenger cabin area are two (or three) large doors on each side of the plane, which allow for carrying two to three rows of freight and cargo. The large wings of the plane, swept back at approximately 37-degrees or 38-degrees feature five extendible slat pieces, which can be extended in three settings in addition to up. The trailing edge devices on the wing act as elevons and flaperons, with some surfaces performing yaw movements, known as ruddervons. The plane features six spoilers on each wing, which when deflected up the elevons would probably deflect slightly down to compensate. I am not sure if the inboard most elevons on the centerbody actually work for flap use as well. The winglets feature two jointed rudders on them each to provide yaw-control. Control would be accomplished via electrical motors with a hydraulic motor back-up for some of the control-surfaces. DFBW would be the standard control method with soft-limits, with Analog FBW. At least some of the hydraulic powered PCU's would feature a mechanical signalling back-up.

The three engines would be mounted in streamlined pods, on the top of the fuselage the engine type depending on overall weight of the plane and range rquirements would either be a GEnx or a high powered GE-90 derivitive. Engines would be controlled via FADEC. Perhaps an engine powered turbocompressor (electrical) can be used to skim off much of the turbulent air from the fuselage to reduce drag and avoid reducing engine thrust at the same time.

To meet footprint pressure requirements, and to support the plane's massive fuselage would be two pairs of six-wheeled bogies, a single middle quadruple bogie, and of course the traditional twin gear nosewheel.

Since some people have expressed qualms about how passengers would like BWB's, I would make all sorts of extravagent claims for bars, and all sorts of stuff to win points over with everybody. If it entered service, it would be just like any other airliner except with the screens. (It's only wrong to lie if I'm not the one doing it is how I see it).

Andrea Kent
 
WestJetYQQ
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RE: If You Could Design A Commercial Jet...

Tue Mar 27, 2007 9:26 am

I've done a few drawings already. One of mine looks quite like a 777 but larger. Also created a (non-comparable) Concorde replacement!

Cheers
Carson
 
Blackbird
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RE: If You Could Design A Commercial Jet...

Tue Mar 27, 2007 10:58 am

I think virtually anybody here if they had carte blanche would take the plunge and build a SST. And not some 100 pax design, but a 300-pax in a two to three class set up with normal or near-normal operating costs.

Andrea Kent
 
2H4
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RE: If You Could Design A Commercial Jet...

Tue Mar 27, 2007 1:54 pm




Quoting N231YE (Reply 11):
I'd also love to see commuter turboprops like this, only bigger:

....Like this, then?

http://i9.tinypic.com/2eun8ko.jpg






Quoting Blackbird (Reply 12):
I'd make a three-engined double-decker BWB with an 800 person capacity like McDonnell Douglas' design conceived of awhile ago...




2H4


 
MCOflyer
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RE: If You Could Design A Commercial Jet...

Tue Mar 27, 2007 2:27 pm

The Boeing 797 with 2 GE engines on the rear (think IL62) and 2 upfront on the wing (777 style).

MCOflyer
 
N231YE
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RE: If You Could Design A Commercial Jet...

Wed Mar 28, 2007 12:02 am

Quoting 2H4 (Reply 15):
....Like this, then?

Ahhh...I forgot about the UDF. Add to my original post, a UDF powered MD-90 or similar.
 
Blackbird
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RE: If You Could Design A Commercial Jet...

Fri Mar 30, 2007 5:04 am

How much would an 800-1,000 pax BWB design that I've described (with modern weight reduction techniques to get around the extra-strength required in the fuselage) weigh in about [/i](Just a guesstimate weight range would be good)[/i]

Andrea Kent
 
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JBo
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RE: If You Could Design A Commercial Jet...

Fri Mar 30, 2007 5:55 am

I'd design a modern successor to the Beech 1900 and other 19-seat turboprops .... something of a lightweight composite airframe with a roomier cabin for 19 pax that's also economical.
 
lehpron
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RE: If You Could Design A Commercial Jet...

Fri Mar 30, 2007 7:22 pm

Quoting Blackbird (Reply 18):
How much would an 800-1,000 pax BWB design that I've described (with modern weight reduction techniques to get around the extra-strength required in the fuselage) weigh in about [/i](Just a guesstimate weight range would be good)[/i]

Use square-cube. As an approximation, find the ratio of the lengths by comparing your plane with something that exists. Then the square of that number will be a projected wing area (something you'd start with) and the cube of the ratio will be the projected weight (which changes as you work with the design).

For example, say we wanted to make something like Concorde with max length = the 80-meter length max. The length ratio is 1.28. The area ratio is 1.64 which means 6400ft, and a cube ratio of 2.1 means this plane may weigh 855,000lbs. Note: square cube assume the plane is simply scaled up from an original spec, meaning both examples are made of the same things. Our 'new Concorde' will assume to be of aluminum. If we wanted to make it out of a composite, divide out the aluminum's density and multiply the composite's density from the empty weight, then add in the fuel. Probably 750k lbs.

Quoting GAIsweetGAI (Reply 10):
Step 1: get
Next: design the A/C.

Jet: a widebody biplane with its engines between the wings and without the traditional empennage.
Or a revamped MD80 or 757.

Turboprop: something in the lines of the DHC-6/7/8.

Finally: build 2 airframes and keep them for my own personal use. (my Precious...)

Oh, and I forgot: go through the aeronautical engineering courses is step 0.5 or 1.5.

You will need a preliminary design (paid by you and whomever you work) to sell your idea to investors before they buy into it and give you more money to build it. You'd need to know the engineering before you start. Note, 'selling the idea' doesn't mean 'selling the product'. Unless they believe IN you, you're out of luck, unless you can afford it yourself to prove to others it is worth investing next time.

For a future SST, the latter needs to be done. I guess you folks know what I want to do.  Smile
 
Blackbird
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RE: If You Could Design A Commercial Jet...

Sat Mar 31, 2007 4:59 am

The BWB would be a bit hard to guesstimate since the thickness of the wings in many areas would be unusually thick.

In length, as I said it would be around 160-feet, give or take a couple of feet, about 290-feet in span, about 40-42 feet tall (wing-tip height probably), however the plane would be a double decker, with a 'flattened' (a wide, highly ovalized cabins divided by walls into 9 to 11-sections, with the outer two to three rows outboard of the passenger cabin, but still in the pressure hull, for carrying cargo cargo) ovalized fuselage of substantial width and volume.

There are lots of variables other than just area and such.

Andrea Kent
 
MidEx216
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RE: If You Could Design A Commercial Jet...

Sat Mar 31, 2007 12:16 pm

Forward-swept wings with canards, and over-wing mounted engines?
 
Blackbird
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RE: If You Could Design A Commercial Jet...

Sun Apr 01, 2007 9:33 am

Could a BWB-type aircraft use petal-style reversers in mid-air safely?

Andrea Kent

[Edited 2007-04-01 02:34:07]
 
lehpron
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RE: If You Could Design A Commercial Jet...

Sun Apr 01, 2007 1:06 pm

Quoting Blackbird (Reply 21):
The BWB would be a bit hard to guesstimate since the thickness of the wings in many areas would be unusually thick.

Relative thickness is almost irrelevant. In aerodynamics, the thickness-to-chord ratio of a wing determines most everything. From there, a propulsion system must be able to overcome the drag at some target velocity.

Quoting Blackbird (Reply 21):
There are lots of variables other than just area and such.

Of course, but you cannot take into consideration that you do not know. Any estimation is incomplete, which must be stated as a work-in-progress. Easy answers aren't.

You have an idea of a 240-foot wide BWB; draw it out. You don't have to publish it online (in fact I suggest against), but in order to get a better idea, you have to draw it out AND you have to do the math. General formulas like the lift equation and calulating range and Vmax still apply, but you have to get a better idea of the drag and lift coeff's. Since a BWB is just a wing, and about 50% of the parasite drag is tube fuselage, the calculations get interesting.

But it is not just about the plane, the thrust of turbine engines changes with inlet air temperature, air density and flight [inlet] velocity. And if your plane is intended to fly faster than Mach 0.6, you have to consider air compressibility. Both air temp and density vary with the speed of sound.

I could give you the formulas, but there are too many. I might as well point you to three books I have which helped a lot:

  • Anderson, John D Jr., "Introduction to Flight", 4th ed. 2000. (go to ch6)
  • Anderson, John D Jr., "Fundametals of Aerodynamics", 3rd ed. (go to ch7,8,9)
  • Hill-Peterson, "Mechanics and Thermodynamics of propulsion", 2nd ed. 1992. (go to ch5)

Nothing specific about BWB's, but if you know what BWB's are (definition, not image), you should be able to figure it out.
 
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Devilfish
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RE: If You Could Design A Commercial Jet...

Sun Apr 01, 2007 2:28 pm

A composite 747SP with twin next generation engines of GE90-115B thrust rating.  Wink
 
Blackbird
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RE: If You Could Design A Commercial Jet...

Sat Apr 14, 2007 7:31 am

To be honest...

If I had carte-blanche and could design any plane I wanted, I'd probably design some kind of Supersonic Airliner. After all, nobody's had the guts to build one other than the Brits and the French. The Concorde may have been impressive, but it wasn't all that impressive compared to the SST designs and the HSCT designs the USA thought up: For one it only had a capacity for 128 pax in a normal airline density, and seat-mile costs that would give most people a heart-attack, it wasn't as fast as the US designs, and had very high takeoff and landing speeds. It's L/D figures weren't quite as good as the US SST designs. Despite this, the Concorde-B would have been nice to see! Not to mention, I hate sitting on an airplane for a long period of time, and recent studies have found that Deep Vein Thrombosis can be a serious health risk and can happen when people remain seated on long flights. Shortening flight times dramatically would easily fix that problem right?

(Some of this is meant to be taken in a light hearted manner, except for the parts that aren't, m'kay?)

If I was in charge of designing a supersonic commercial jet, I'd be building it obviously with some degree of economy and safety in mind, but also I'd be building it to 1-up the rest of the world. After all, it's been so long since the idea of a supersonic airliner has been floating around, but other than the Concorde and the Tu-144, none of them flew!

First of all, I'd want it to be able to fly at Mach 3. That's what the SST-program aimed for and for the simple reason that Mach 3 is faster than Mach 2. And considering we've been waiting since 1966 for supersonic commercial flight, we deserve to get Mach 3 after a 41 year wait! Additionally, I'd want it to carry around 320 or so pax in a three-class set-up since that would be the most economical amount to carry. One of the Concorde, and the SST's pitfalls were short range, so I'd want a range on the order of 5,750 nm to 7,500 n/m if not more.

To achieve a desirable speed and range with minimal fuel-consumption, I would want to design the aircraft using airfoils with ultra-low transonic-drag levels of Sonic Cruiser calibur. Whether this would entail designing the aircraft like a long-stretched-out Sonic Cruiser with a thinner fuselage, a sharper nose and increased leading-edge sweep or would allow a somewhat more conventional design with ultra-efficient CFD-taylored wings, I'm not sure (I would obviously prefer the ability to have some more freedom in the design rather than just stretching and thinning the Sonic-Cruiser out -- something which would work, but would take away a lot of design-freedom, may make it unfeasable to make the 320 pax target, and would probably prohibit a more versatile design) -- assuming that such ultra-low transonic foils could also achieve high-efficiency flight at Mach 3. Reducing transonic drag particularly would allow much more rapid acceleration and allow for more time at Mach 3 -- thus making Mach 3 crusing more economical. It also would also allow for less fuel weight, thus making the plane lighter for the same range. While not a requirement, it would be preferable to have a design who's shift in the C/L could be controlled throughout the speed range using a canard, and some aerodynamic contouring to the airfoil-design used providing it would not increase transonic drag, or at least not increase it significantly and would not have notably adverse effects on the airplane's cruise L/D-ratio.

A big issue with the aircraft's design would almost undoubtably be sonic boom emissions. I've heard of many solutions to this issue, many of which are difficult to implement, however an idea which features a slightly blunter nose than one would typically use could negate the underpressure behind the shock thus preventing shockwave coalescence which amplify greatly the shockwave levels. This idea would work well, however the problem I see with it is that such a design would produce more drag on the nose than would be ideal. I would propose an alternate possibility. One could use a somewhat more conventional long nose which would would utilize the injection of small amounts of hot-bleed air in a precisely release pattern which would quickly kill the underpressure behind the shock by using positive pressure. The exact amount could be very miniscule, and controlled by a computer which for a given mach and IAS reading would inject the correct amount of bleed-air to blank the underpressure behind the shockwave. A porous area located a given distance behind the injection point would skim off excessive turbulence air through an LFC system. Since this would be fairly close to the bow of the nose, it should work okay. The heat adds energy to the flow even though it prevents the waves from coalescing, and actually changes the local speed of sound. To further reduce the effects of sonic boom levels, the inboard wing would use some dihedral. The fuselage would be contoured in various ways to lower sonic-boom emissions. Additionally, the use of laminar flow would be used on the wing's leading-edges with natural laminar flow behind those areas. To provide de-icing funcions, bleed-air could be back-flushed through the pores when on the ground. The tubing and ducting to allow this to work would require some physical flexibility since the leading-edges of the wing may be drooped for takeoff and landing, additionally there is a possibility that the leading edge may be adjusted in small amounts to reduce sonic-booms and to provide extra lift, and possibly some trim-assitance.

Most of the rest of the issues lie in the engines and the propulsion system consisting of the inlet, the engine, the sound suppression system and the nozzle. Lockheed to my knowledge was able to demonstrate in the 1960's that a wedge-splitter type inlet with the proper contouring, minimal external cowl angles, and the arrangement of slots and porous surfaces could achieve a high pressure recovery and self-stabilization without the use of moveable parts. The HSCT program went back to a variable geometry inlet since even Lockheed's design could potentially still encounter an unstart-- the inlet could simply recover from it acceptably. Unstarts weren't considered acceptable in the sixties, and now they certainly are not tolerable. However, it is my opinion that a fixed inlet could still be do-able at Mach 3. The HSCT relied on a laser system that could sense clean-air turbulence and adjust the inlet accordingly, such a mechanism (the laser scanner) could be incorporated, with the inlet fitted with the provision for active laminar flow control in addition to passive. When a disturbance is detected, the suction can kick on and it would quickly skim off the turbulent air preventing it from disrupting the inlet. If do-able, the design would allow a fixed inlet to achieve Mach 3 performance, and be able to adjust itself to airflow even ahead of the spike by use of laser-scanning. Since engines are cylindrical, I prefer the conical spike instead of the wedge splitter, however the design could work with either design-- wedge or spike as long as the angles are the same. The engine would be of a variable cycle type which would produce lower noise emissions at low-speed than the turbofan used on the HSCT program, and would provide superior high-speed performance. This would also require less low-speed sound suppression, or greater sound suppression with the same degree of cooling air. The engine would operate as a turbofan at low-speed with light-weight composite scimitar shaped fan-blades with variable pitch and variable guide-vanes to maintain the same flow of air into the compressor regardless of it's operation as a turbofan. To allow this, the blades may even be fitted with vortex generators or a type of "sharkskin" which is basically millions of tiny vortex generators. At higher speeds, the engine transitions into a turbojet. I've been told that as counter-intuitive as it may seem, slight afterburner use at Mach 3.0 would allow a specific range increase-- unfortunately afterburners are generally too fuel thirsty, and even worse, produce horrendous amount of NOx emissions. The solution would be an outer-annular combustor which would get it's bypass off the HP compresor, and upon combustion would yield an extremely high velocity exhaust which would be conducive for highly efficient high-speed flight. To provide a good compression ratio across the whole engine, the HP compressor may be able to use variable guide-vanes and even a variable blades like the Variable Stream Control Engine that Pratt & Whitney proposed in the early eighties. The design would essentially be a dual-bypass VCE utilizing characteristics of the YF-120, the F-119, the VCE, and all sorts of new technology available. To maintain acceptable emissions, the combustion chambers would utilize a LPP-type combustion chamber which use prevaporized fuel, premixed with air in a lean fuel/air ratio in a dropless environment in an antechamber and then ignited and burned up rapidly in the combustion chambers. The primary combustor would be dual annular with the inner annulus only activating past a certain point, and reduced in power under some conditions at high-speed to reduce fuel-consumption while the outer-combustor is being used. The combustors would by necessity use no film air at all, and use no dilution holes. All the air goes in to the chamber itself! To allow such high temperatures without film-air cooling, high-temperature ceramic-matrix composites would coat the combustion chamber, and likely high temperature metallics would be used. The turbines would utilize high temperature single-grain cermets with a CMC coating, and an elaborate air-cooling system to allow for a good pressure-ratio. The sound-suppression of the engine would come partially from the engine's fan-bypass mixing with the high temperature hot-stream air. The rest would come from part of the nozzle. Rather than using a 2D nozzle, I would prefer to use a 3D cylindrical nozzle. The job can still be done, just you'd use a bunch of smaller span-wise segments that would all interlock together into a cylindrical shape when deployed. They would attach to a axisymmetrical fairing in the duct which would be connected to the walls by a series of struts, and a series of auxiliary doors would open up-stream of the sound-suppression chutes. The exhaust blowing through would draw air in... the outside air, the fan air, and the core flow would all be mixed together, resulting in a slower cooled exhaust flow that would also be considerably quieter. I'm not sure what the current noise levels would permit, but the degree of cooling air would be increased to what is necessary to get the job done while trying to avoid losing excessive amounts of thrust. For high-speed climb and acceleration, the chutes would retract out of the exhaust stream, and the auxiliary doors would be closed. The ducting behind the engine would be configured in a convergent/divergent fasion to achieve supersonic exhaust velocity. The rear of the nozzle would consist of petal-type reversers designed to provide braking on landing and for use in mid-air for speeds up to Mach 1.2 (this figure was derived from the L-2000's specs).

In overall design, the plane would probably feature a cranked-arrow/double-delta esque wing with a moderate degree of wing/body blending with a degree of twist/camber, and some inboard dihedral. The leading-edges would feature a type of variable-droop flap to provide optimal lift across the speed-range. The trailing-edge elevons would be able to droop for use as flaps to some extent. It is likely the plane would feature an upward canted canard. The fuselage would feature, likely extensive and elaborate area ruling to provide low-drag and reasonably low sonic-boom levels. As for the tail design, I'm not sure. The inverted-V tail would probably work quite nicely. Since Lockheed has it patented, the design would need a couple of small changes so that it would circumvent this problem. To provide good yaw control, a portion of the vertical fin can pivot to provide yaw control. The plane would feature four engines placed in individual pods properly placed under the wings. Due to the fact that this airplane would not feature any conventional spoilers due to the elevon set-up, a type of speed-brake or speed-brakes would be required-- the trailing edge of the vertical fin could feature a split break because the motion of the whole tail is what produces the yaw. The thrust-reversers can be used below Mach 1.2 in mid-air. To support the airplane's weight, the plane would feature a triple-legged strut with six-wheels on each, and a traditional nosegear.

In older designs the window-size was pretty much restricted, but lately it seems as long as you can prove that the odds of the given object, in this case the window, are so low as to be considered astronomical you can pretty much do whatever you want. So of course, first order of the day-- bigger windows! I'd like them to be at least 777-sized using an elaborate, but light weight structure (like 3 sets of two ultra thin, light weight high-strength glass with a flexible medium like a gel or a fluid or epoxy or something to make it like bullet-proof)

To make the overall airplane design light, various means would be achieved involving structural engineering techniques that would yield light weight, but extreme strength. This would involve the use of composites of various sorts, various high-temperature metals, particularly those of each that can be superplastically deformed and diffusion-bonded, composite reinforced metals, and the like. It should be of a respectably low weight, and be sturdy as hell. Unlike modern day sissy's who design airplanes just to barely make the ultimate load requirement, I would want this plane to beat it by a long shot before breaking.

Regarding the plane's control surface set-up I have no idea. But the plane should have FBW, artificial feedback, soft-limits, auto-trim, if electrical motors are used, some hydraulic motors should be used for some of the control-surfaces in event of electrical motor failure, and some degree of mechanical signalling in the event of a digital computer problem. The plane should feature a self-diagnostic computer system like the 777 has. The plane should feature cameras located in various areas to provide ease of taxying, and digital entertainment for the passengers. Since the airplane has no droopable nose, the plane requires an elaborate set of clustered-sensors and cameras that provide data to each pilot via viewscreen. The visual system should be able to show high-definition image color view during normal operation. Due to the fact that some of the sensors involve weather radar, it can be set up to see through clouds, due to the fact that data from the aircraft's radar, it can show the location of other aircraft, wether they're closing on them, falling behind, if they're above, below, climbing, descending, etc. Since the clustered lay out involves multiple sets of cameras, even if one set fails, a lower resolution can be displayed. To provide the optimum HUD layout, the display itself should also be able to display Heading, Altitude, Indicated Air Speed, Mach Number, Pitch Ladder, Vertical Speed, Angle of Attack, Sideslip, and Engine Data, and anything else needed, perhaps ILS data when being used. The plane's engines would be controlled by a FADEC with the associated back-up and redundancies. Taxying on the ground would be done by a tiller on both pilot's sides, and by simply using the rudder pedals.

Like most airplanes designed to fly quick for a long time and heat-soak, the plane would use the fuel as a heat-sink. The fuel would be inerted by nitrogen.

Of course, that would be if I had carte blanche, which I don't.

Andrea Kent
 
747400sp
Posts: 3900
Joined: Sat Aug 09, 2003 7:27 pm

RE: If You Could Design A Commercial Jet...

Sat Apr 14, 2007 11:24 pm

Think of a MD12 size Sonicruser with oceanliner like stair ways and an around wind shields like on the 747, L1011 and CRJs, but with a sonicrusers like out line. It would have three aslies on the buttom deck and two on the top. It would have four 140000 lb trust engines with a low deep baseful sound. It's landing gear would have an four wheels for the nose gear and twentysix wheels main gear. It's lower cabin would be 26 feet wide and it's top cabin would be 20 feet wide with a lenght of over 280 feet and a hieght of 85 feet at tail tip. It's crusing speed would be mach 0.99 with a top speed mach 1.
 
SCAT15F
Posts: 719
Joined: Fri Feb 09, 2007 8:34 am

RE: If You Could Design A Commercial Jet...

Sun Apr 15, 2007 1:10 am

A 747-8SP.
Same length as the original SP (184.7 ft), but with 747-8 wings and engines, and "standard" (not pinched) rear fuselage. Same size (SP) tail and rudders, and 747-300/400 stretched upper deck, plus use of crown space.

Max T.O. weight: 775,000 lb (more fuel)
Thrust: 266,000 lb +
Capacity: 275 passengers in all business class (for long range comfort)
Range: 9800-10,000nm
Cruise speed: mach .90
Cruise altitude (certified) 48,000 ft

no step climbing necessary due to thrust to weight ratio and ultra low wing loading.

say goodbye to those Citation X records!  box   bigthumbsup 
 
Blackbird
Topic Author
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RE: If You Could Design A Commercial Jet...

Sun Apr 15, 2007 2:24 am

It actually would have been pretty cool had an MD-12/NLA type plane would have been built when they had the chance to rival and possibly one-up Airbus.

Andrea Kent
 
Blackbird
Topic Author
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Joined: Wed Oct 06, 1999 10:48 am

RE: If You Could Design A Commercial Jet...

Tue Apr 17, 2007 3:51 am

Anybody have any momre ideas?

Andrea Kent
 
flinhion757
Posts: 229
Joined: Mon Jul 10, 2006 5:26 am

RE: If You Could Design A Commercial Jet...

Tue Apr 17, 2007 8:00 am

Quoting Flipdewaf (Reply 1):
multibillion dollar bank loan



Quoting Blackbird (Reply 3):
billion dollar bank loan these days

Yah... DUH!  dollarsign   dollarsign 

4 GE engines with the curved blades. A 4-6-4 seating config. And have top speed be 600kts and altitude 75,000 ft. Can't forget the Air Marshal Quarters and Upstairs sleeping for EVERYONE. Computers in seats backs, AAAHHH! One last thing, Aircraft Shopping Network.
 
Blackbird
Topic Author
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Joined: Wed Oct 06, 1999 10:48 am

RE: If You Could Design A Commercial Jet...

Fri Apr 20, 2007 2:30 am

I think the 800-1,000 pax BWB idea seems the most realistic. Using all sorts of state of the art technology to lighten the overal frame and allow for a reasonably light fuselage, fold-able wing-tips and slight geometric changes from the original design to allow for Mach 0.88. Oh, and use an engine driven turbocompressor whether electrical or bleed-air to skim off some of the turbulent air on the mid-section fuselage so the engine doesn't have to ingest it directly and lose a lot of thrust.

The only major obstacle, other than weight reduction is keeping the passengers from being all disoriented since the cabin is wide as hell and there's very few windows. My guess would be a lot of flat-screen TV's (one for each row, which can display a front view, a side view, a side/forward view, a lower view, an over the top view and also a text-display that tell the passenger if they're going to feel a roll, if their side of the plane is going to go up... or down and how extreme it's going to be.) and some extra air-sickness bags.

At least, to me that sounds to be the most realistic.

Andrea Kent
 
Blackbird
Topic Author
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Joined: Wed Oct 06, 1999 10:48 am

RE: If You Could Design A Commercial Jet...

Sat Apr 21, 2007 2:38 pm

You know what would have been great? If McDonnell Douglas or Lockheed persued twin-engined variants of their DC-10 and L-1011 (Respectively) designs? It would have lots of commonality and it would satisfy American's original requirement, and probably compete well with the then new A-300

Andrea Kent
 
747400sp
Posts: 3900
Joined: Sat Aug 09, 2003 7:27 pm

RE: If You Could Design A Commercial Jet...

Sat Apr 21, 2007 10:13 pm

Here is a design I would have done in the sixties or seventies. I would have design a five engine wide body, it would had a cabin width of 21ft a length of 247 ft and a wing span of 228 ft, and it's tail height would have been 67 ft tail. It would have looked like a 747 with a giant version of the DC10 tail on the top. The A/C windshield would have been full curved, not just curved on the front and strait on the side like the 747 or strait on the front and curved on the side like the DC10. The upper deck hump would have been larger than on the 747s hump. It engine choice would range from P&W JT-9, GE CF-6 50, and RR RB:211 524 C2 to D4. The lowest cruising speed this jet would had was mach 0.90, with eough range to fly on the LAX-Perth route, what's right ! LAX to Perth. It would have been nice to see this A/C in Pan Am, JAL, KLM, Alitalia, MAS, UA, AA, BA, B-Cal, CO, UTA and any other airline that come to minded.
 
CXfirst
Posts: 3023
Joined: Tue Jan 30, 2007 8:13 pm

RE: If You Could Design A Commercial Jet...

Sat Apr 21, 2007 11:04 pm

Quoting Flinhion757 (Reply 31):
A 4-6-4 seating config

That would be fun

-CXfirst
 
Blackbird
Topic Author
Posts: 3384
Joined: Wed Oct 06, 1999 10:48 am

RE: If You Could Design A Commercial Jet...

Mon Apr 23, 2007 12:30 am

4-6-4 might make evacuation hard. All the passengers have to be out of the plane in 90-seconds with half the exits blocked for certification tests (hypothetically of course)

Andrea Kent

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