Lets build lightest fastest aircraft

If we were put in charge of building the lightest fastest aircraft what materials would you use and why?

Ill start: AlBeMeT, Its stronger than steel and half the weight of aluminum Its already used in the F22 stealth fighter F117 stealth bomber and the Comanche Helicopters.

I was unable to open your link.

This metal, how new is it since it is used in F-117 it can't be totally new.

Don't we always need a bit of titanium

Originally posted by Figher Master FIN
I was unable to open your link.

This metal, how new is it since it is used in F-117 it can't be totally new.

Don't we always need a bit of titanium

Its new to the public the link is in PDF link. Titanium is a good one.

How fast are we talking?


The service temperature of your AlBeMet is dangerously low for Mach 3+ flight.

If we're going for all out speed, then we're best off leaving the atmoshpere entirely - you can't beat orbital speeds while restricted by atmospheric drag.

If that's the plan, we'll want GEM (Graphite Epoxy Motor) solid rockets to get us up to altitude. For the airframe we'll want carbon fiber or titanium for the structure, and ceramics for the heat shield.

In my spare time I've been around and looked at various options for making aircraft lighter. I've even designed an airframe that I've lovingly named the Sand Shark. Yeah, I do aircraft in my spare time. Because it's far more fun than work.

The ideas I had incorporated were to make it as streamlined and as light as possible.

It's got 2 F-5-esque engines. Small and light.
It's got really curved delta wings. It's sort of like shrunken Concorde wings.
It's got two tails that resemble shortened wings of the plane.
It's got an intake that surrounds the side and bottom of the plane.
Only exposed areas are coated with titanium- the rest is aluminum alloys.

I'll see if I can pull up the drawing I did of it. I did a side and top view, but not a front view. Because I'm lazy and not particularly good at drawing frontals.

Keep it below 5000kgs empty weight!

Ok. Why not work in another way. Take the lightest fighter in the air today, the Tejas @ 5500 kg empty wieght, and then come up with ways of making it lighter.

It will be tough as over 90% of the surface area is already carbon composite.

Keep the same engine GE/Kaveri.

Lets see how much we can increment the top speed of Mach 1.8 simply by reducing the empty weight.

Any super light aircraft is only useful for one role these days- maneuvering. We quit making single role fighter with about the F-104. Even then they retrofitted it for the Luftwaffe with all sorts of external weaponry. Nobody can afford to do R & D at what it costs now to end up with, let's say, only a more maneverable F-16.
World War 2 fighters were already above 5000kg so that's weight is pretty unrealistic. We've been locked into multi-role aircaft with multiple weapons systems since then too.

I think they should save weight wherever possible by using whatever exotic material they can as long as the costs are reasonable. 200 million per copy for the next latest plane is ridiculous.

As a "what if" project it sounds cool but it ain't gonna happen in the real world any more.

Anyone remember the Folland Gnat form the early 50s? 659 MPH from a 4,800-lb empty/9,000- lb loaded weight. They were built inder license in India. THAT was a truly light mini-fighter.

Max Weight Savings Hmmmm?

No pilot. 250lbs.
No bang seat. 200-400lbs
No OBOGS or LOX Tank. 450lbs
No Canopy 350-750lbs.
No HUD, MFD or secondary flight instruments. 150-200lbs.

All primary structural elements are cast integrally, skin-as-spar without fasteners of any kind. Each basic component (left/right wing, fuselage segments etc.) may be separately replaceable on a mix-and-match cannibalized maintenance basis.

All hydraulics to be stripped. Replaced with electrical or local-cicuit pneumatic actuation. This means power by wire as well as fly by wire in a single integrated databus. It also means things like the landing gear are run by single-use discharge bottles which kick both doors and struts, possibly as telescoping rather than folding mediums to reduce occupancy volume and tire:fuselage clearances (rolls in well). Alternately, para-air bag, dynamic net or hook recovery or even ablative skids might be considered.

No tails. All controls by simple (paddle in stream) thrust vector or bleed air RCS systems in combination with morphing memory-shape plastics with internal actuation so that the weight of separate control surfaces and seals/covers are avoided. If historical problems with 'blown flap' issues can be resolved while using temperatures probably 4-5 times as high with a pulsejet or pdwe (or a RALS), then ESTOL or similar trades in approach speed vs. controllability might be investigated as further weight reductions for both primary structure and carry through loads on gear due to vertical loads. 90 knots at 10fps vs. 130 at 5 etc. etc.

No access panels. Since the stealth/aero/water seals and structural cutouts for these are equally complex and weighty. All systems designed to a singlepoint fail-operative level of functional redundancy for a minimum of 1,000hrs guaranteed contractor spec. All systems accessible hower from INSIDE a single, separable, wing:body primary join (which should also be pressure sealed under normal conditions to isolate environmentals).

No primary turbomachinery (banks of APU styled lift augment engines might be another story). Since this inevitably means heavy, nested, spools of hot-section metal or ceramics, as well as condi nozzles. Aircraft to function purely by pulsejet at low levels/speeds and scram or PDWE at high. You specify nothing about loiter or mission role performance so there is no really efficient way to judge optimum fuel type but a heavy fuel such as diesel or boron additive based options makes sense, provided Mach point stays below gumming thresholds and there is no secondary cooling requirement. Above Mach 3 and you probably need to look at methane or hydrogen which brings it's own problems. I would probably electrochemically deposit a layered ceramic or rare earth allow directly to the composite skin, using electron beam lithography to cut out giant 'circuit pattern' fuel feeds as this would also cut down on material/fastener weight for separate thermal management and possibly startup/auxilliary power systems (minicut APU/JStarters with imbedded microturbines 'preheating' a given fuel-air mix for subsequent injection at a given hypergolic/pyrophoric premix state.

No or limited sensors. Since these imply /all kinds/ of cooling, electrical generation and material surface discontiguities inherent to dielectric or optical performance. Unnecessary in a system which relies on offboard sensors and/or dropped 'brilliant' munitions to do actual recognition/sorting/engagement of targets.

Limited CNI suite. No HF shunt array, no multiple blade antennas for VHF/UHF. ONE multiband array with integrated hi-med-low band sub elements integrated. More like a subs forward sonar dome than anything currently in aircraft.

If practical, experiments in lightweight plasma generation (electroreactive striplines imbedded atop hot-air bleed ducts or similar) might be considered, this would let you design a single function hot-ceramic nose cone and LE material behind which the airframe sheltered in a plasma sheath that both isolated it from extreme temperatures of high Mach and spooled up the aerodynamics of transitional flight envelopes in the low transonics and mid supersonics.

Preloaded, Conformal or Tip Mounted (preshaped) 'mission modules' varying in appearance between the underbelly pod on the F7U and the tiptanks on an F-104 for all role/sortie variation in MEP/fuel loads. Probably with independent electrical generation and datalink capabilities to simplify compatibility issues. Offboard task handlers communicate with the pods and the airframe as separately upgradeable and secure entities with minimal aerodynamic influence on the cruise state of the overall vehicle and rapid combat turn/role change options on the ground.


KPl.

I can say that B-2 structures are made up of pure composite and very few metals like titanium and aluminium are only made up of connect the wings blend into the body. USAF said that it is the most strongest and long-lasting aircraft in their inventory. There is a but and its nightmare for maintence crews to do their jobs on that aircraft. The composites are very delicate to take care of. Still, its beautiful aircraft!

I just watched one of the show on Modern Marvel and the USAF said that F-117s are having totally 80's technologies except for modern avonics and fiber opic system that only can improve and make it flies better. They said that the exterior of the jet is more expensive to take care of than to work with F-22. Isn't that something to ? Its not so new jet anymore.

[edit on 30-9-2006 by OneMyrmidon]

Originally posted by AlBeMet

Originally posted by Figher Master FIN
I was unable to open your link.

This metal, how new is it since it is used in F-117 it can't be totally new.

Don't we always need a bit of titanium

Its new to the public the link is in PDF link. Titanium is a good one.

Yes the titanium alloy is very good one but right now, it is very difficult to obtain the titanium due to pointless political crisis. Like I mentoined about B-2, the composite are far more stronger and easier to make and more lighter.

Crashed alien disks recovered used interesting metal alloys with very thin layers bonded together this gave the metal amazing qualities and when charged caused a kind of anti-gravity effect.

OM,

>>
I just watched one of the show on Modern Marvel and the USAF said that F-117s are having totally 80's technologies except for modern avonics and fiber opic system that only can improve and make it flies better. They said that the exterior of the jet is more expensive to take care of than to work with F-22. Isn't that something to ? Its not so new jet anymore.
>>

As I recall, the first F-117 FSD aircraft flew in early May or June 1981. The Have Blue back in late '77 or the beginning of '78. While the whole precursor Senior Trend effort was authorized way back in 1973 or 74. The entire blackjet was a hodgepodge of 'borrowed' systems from the F-15 and 16 and A-10 efforts which were then 'state of the art' and thus considered non-developmental engineering source items by which ADP saved engineering time and effort.

Though it has since undergone two major and one minor upgrades, it would therefore be more accurate to say that the jet is in fact based on 1970s technology.

For comparison with the civil world where the only thing that matters is passenger count, M&R and gas figures, if you bought a 727 in 1981, wouldn't you consider it dated technology today?

>>
I can say that B-2 structures are made up of pure composite and very few metals like titanium and aluminium are only made up of connect the wings blend into the body. USAF said that it is the most strongest and long-lasting aircraft in their inventory. There is a but and its nightmare for maintence crews to do their jobs on that aircraft. The composites are very delicate to take care of. Still, its beautiful aircraft!
>>

Modern composites are not really any more vulnerable to damage than metal structures though they are harder to repair once 'dinged'. The reality being that _strategic stealth_ is what makes the B-2 such a bear to maintain because it's flight profile and endurance forces it into some extreme conditions (refuels in the mid-20s right in the hear of the storm belt, transits in the high 40-50s, waaaaay up high in the UV saturated territory).

Add to this the overall size, complex airfoil LE shape, and the former use of tape'n'butter style LO sealing (like drywall mud and seal tape) and you have a very vulnerable, agitated, airframe that is hard to take care of because it requires 100% signature control measures to be monitored and maintained at all times between extended flight intervals (albeit over a limited number of sorties).

AHFM and other tricks along with sheer experience on the ariframe are helping but the aircraft is still very much a pimped and primped prima donna.

Of greater concern is the fact that composites _are_ a nightmare to build as well with major shrinkage and uneven curing always a problem while their internal structures are not always amenable to remote (X-Ray, Ultra Sound or Radar) mapping for imperfections which leads to a lot of early production wasteage as you do destructive tear downs to get the cuts and the autoclave and the finishing processes down pat.

In fact, Northrop engineered an aluminum wing backup for the Batarang because they didn't believe the composite one would work.

Nor are 'all composite' vs. 'hybrid' designs an easy-out option because imbedding metal pieces into composite spars and frames often causes differential thermal activation (inside and out, the pin or bolt acting as a heat sink) during cure and even when done right is effectively a structural void inside the composite which WILL apply load stresses that don't transfer across to the whole structure evenly.

Which makes any area around a metal/composite join altogether more fatigue prone.

Indeed, one of the things which destroyed the ATA effort was the USAFs refusal to play ball with the Squids in handing over their composite engineering experiences so GD/McD had to choose between engineering for LO, engineering for weight and engineering for structural design issues with a budget that was barely adequate for any one of the three.


KPl.

Originally posted by kilcoo316
How fast are we talking?


The service temperature of your AlBeMet is dangerously low for Mach 3+ flight.

Actually Its used in satellites for it stability under extreme hot cold conditions of space, it doesn’t expand or contract from hot to cold (direct sun to darkness in space is extreme)

Granted there are different grades of Albemet and some are not known to the public but even the ones that are can sustain mach 3+ without even twitching.

Beryllium and AlBeMet Products The superb qualities of beryllium are well known. Its lightweight, strength and superior thermal performance make this material a solution for many engineering challenges

One form of AlBeMeT 162 has a melting point of 1000+C

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Added LINK

[edit on 2-10-2006 by masqua]

[edit on 2-10-2006 by AlBeMet]

You'd want to get rid of windows. It weighs less to just put tiny cameras where needed. Windows carry a weight penalty not only for the glass or polycarbonate. There is also a weight penalty for the window gasket hardware and the structural reinforcement around the window. A windowless aircraft can have a much lighter airframe. Plus it is cheaper to build.

For the lightest possible aircraft, you would want to replace the hundreds or thousands of kilograms of copper wire with sodium electrical wire. For the impulsive loads of control circuitry, sodium wire weighs only about 1/100th as much as copper. For power cables carrying continuous current, sodium wire weighs only 1/3 as much as copper wire.

Sure, it is an experimental product that hasn't been completely tested yet. It is not even expected to be offered commercially until sometime around the end of the year. But you didn't ask how to build the safest and most boring aircraft. You asked for the lightest and fastest aircraft.

There is info about sodium electrical wire on sodiumwire.com