Art: Reference pic, 35 ton Endo/Exo atmospheric interceptor

[wbnc]

Current working Designation "Tigershark"
They are ground based system fighters for use by local squadrons, and planetary forces rather than fleet deployment.I am working on the stats but so far I am not completely satisfied with them...they are bloody expensive due to the cost of software, and comuters they carry.


Thrust Max for TL with Hybrid Reaction/Gravitic Drives
Armor: Light 6 points of armor
the Crew is a pilot with a virtual crewman, for handling engines, sensors, and EW in close combat.
Software: Fire control, Electronic warfare. Launch Solution ( forget the proper names.and my copy of the High Guard Preview is on my home computer..)
Advanced military sensors, and ECM suite.
Broad Spectrum EM, and Emissions absorption.

Weapons are either missiles and a pulse laser, or a Torpedo barbette....The illustration is not completely accurate for Traveller but that's easy to tweak...I am also working on versions that mount Particle beams, or fusion cannon in modular pods, so they cna be deploed in a ixed flights with various weapons loadouts. Or carry extra fuel for long range intercept pursuit missions.

At around thrust 16 even if they launch after a commerical vessel leaves, they should overtake it before the ship can reach Jump limit.they can also cross a system much faster than a patrol boat or SDB...so anyone who runs better have one heck of a head start.

The winglets are fixed, although they can fold back and down for landing and storage The mount the fighters ECM systems and emitters that allow it to change it's sensor profile to shift the center of its signature away from the hull to confuse missiles and enemy sensors. They look pretty flimsy but they do not support the fighter or a significant amount of stress during atmospheric flight, aside from adding some extra stability in flight. The fighters wings and gravitics handle the bulk of the load.

to function in a variety of atmospheres, without physical alteration the fighter uses air forced through channels in the wings to alter the airflow over the wings to create a range of wing profiles.

I picture them mostly as point defense/pursuit fighters. Either loitering around fuel sources in a system, or operating from ground stations or orbiting platforms to provide fast reaction groups to check out any ship or small craft that attract the defense grids attention.

The cockpit is a completely enclosed capsule with optics, and Lidar units feeding the pilots HUD, or a holographic display on the inner surface fo the canopy. ...just in case there is a panel that can be ejected to allow for direct view..but to be honest anything that knocks out it's sensors will probably render the fighter inert and out of control to begin with.

 

[Condottiere]

How fast are they?

You don't want that external ordnance in atmosphere to make an involuntary separation.

 

[wbnc]

In this configuration Mach one or Mach 2 with higher dash potential...mostly due to the external payload...the wings are positioned far enough back to keep the ordnance inside the shockwave created by the aircraft...at least they should be..I was lazy and didn't get out the slide rule, and do the math on that.

the weapons loads vary by mission.These fighters are carrying torpedoes instead of missiles...if they were ready aircraft that needed to get to orbit quick. They would be armed with missiles in a streamlined centerline pod. Torps are a bit hefty for that type of arrangement.


In theory, the fighter has the thrust to reach hypersonic speeds. But that's would only be in the event of needing to reach orbit PDQ...it would be easier and faster for it to climb up to near space, make a hypersonic dash then descend down to combat altitudes...or simply fire from near orbit. with several flights on combat air patrol in low orbit they could make a dash and then descend at Mach speeds.

 

[phavoc]

Are the middle X wings there for anything?

You have no need for wings with anti-grav, and the other control surfaces would work fine for additional in-atmo work. An alternative might be to create a pair or internal rotary launchers that bulged out at the bottom, which would provide you with less drag (needed for any hypersonic travel).

Hypersonic craft are an oddity in Traveller, as the normal anti-grav ships don't have enough thrust to go that fast. Not impossible to make though, just not the norm.

 

[Tenacious-Techhunter]

Yeah, those x-winglets... I’m not convinced they contribute in any helpful way. The one reason I could see them existing is as a mod for a low density atmosphere planet, to get extra lift and control surface... making them sort of “biplane-like”; but otherwise? I’d drop them. I don’t see it as a fast turner, either; other wing shapes are going to have the advantage in terms of wing loading.

You could apply a bit more Whitcomb Area Rule, too.

 

[wbnc]

Are the middle X wings there for anything?

You have no need for wings with anti-grav, and the other control surfaces would work fine for additional in-atmo work. An alternative might be to create a pair or internal rotary launchers that bulged out at the bottom, which would provide you with less drag (needed for any hypersonic travel).

Hypersonic craft are an oddity in Traveller, as the normal anti-grav ships don't have enough thrust to go that fast. Not impossible to make though, just not the norm.

When I drew this up I was creating it for a specific setting so a lot of features are setting specific...but that would take a few pages to explain fully so I had to skip a lot of that.

The X-foils are part of the ECM/EW/Sensor system. the mount antenna, transceivers, and thermal decoy devices. The allow the fighter to change it's sensor signature to either confuse identification software, or decoy missiles away form the main body.

Also this fighter was one I drew up for a race in my own setting. One of their design quirks has led to their starships being forced to mount large vanes to help stabilize their Jump bubble. and keep it from collapsing in on their ships. So they tend to use the feature on other craft as well.

The presence of wings and the hypersonic speeds are also part of the setting. one of my house rules is that Gravitics create a very distinct EM noise, and it can be used to detect or target a grav vehicle.

The race I mentioned like to pull a dirty trick in atmo...they kill their gravitics and approach a target using aerodynamic lift alone. for a high altitude craft it's not as effective but at low altitude using terrain to cover the fighters approach it gives them a slight edge.

The race designs most of their atmospheric craft to be able to fly without gravitics as a general rule.it allows the to glide, or cruise on minimal power for extended periods, or make a safe entry and landing with no gravitics.

Once again that's for setting reasons they tend to have issues with their tech being extremely powerful but prone to breakdown... they build systems that are pushed to the limits of their manufacturing base So tend to lag behind other races in reliability, which means they include features to compensate.


The hypersonic dash capability is for getting to orbit or intercepting potential hostiles. the pilot can boost rapidly to sub orbital, or low orbit altitudes, use full burn without worrying about drag then either dive back into atmosphere or fire from altitude at aircraft, small craft, or starships below them.

the design cheats to get around frictional heating, by using forced air to create a boundary layer of varying profile the wing surfaces are not directly in contact with the hypersonic air flowing around them...the drag is still impressive but grav assist negates a lot of the weight of the aircraft giving it a very high thrust to weight advantage..and it is powered by a fusion reactor that could service a good sized town.

Yeah, those x-winglets... I’m not convinced they contribute in any helpful way. The one reason I could see them existing is as a mod for a low density atmosphere planet, to get extra lift and control surface... making them sort of “biplane-like”; but otherwise? I’d drop them. I don’t see it as a fast turner, either; other wing shapes are going to have the advantage in terms of wing loading.

You could apply a bit more Whitcomb Area Rule, too.

I mentioned it above but the x-foils aren't for aerodynamics, they are basically antenna arrays...they dont add much to the desings perfromance, but they do serve a purpose..


I gave it some taper but i's not easy to see...the next revision might have a bit more taper to the waist...
The Area rule could be sidestepped by creative cheating.The aircraft is designed using airflow control. jets of forced air are injected into the slipstream to alter how it flows around the aircraft. If the aircraft used a structural feature to reduce drag the design would need to reconfigured for varying atmospheric conditions, with he airflow control system it can be done automatically to get the best performance out of the aircraft in any atmosphere...it's also why I included a virtual crew software package to reflect the complexity of it's systems...

the virtual crew software has game mechanics value as well, but I also wanted to allow for it's non mechanics features.

 

[Tenacious-Techhunter]

Rather than the x-wings, use upper and lower wing-tip winglets, and mount the ECM units there; you’ll get more or less the same distribution.

The aerodynamics of your craft is going to be the same wherever the thrust matches the drag, regardless of atmosphere; anywhere that shares the same Reynolds Number is going to have matching performance, regardless of air density. Don’t worry about having to do custom streamlining; there’s no such need; it will be other factors that determine operating condition based inefficiencies in your design.

 

[wbnc]

Rather than the x-wings, use upper and lower wing-tip winglets, and mount the ECM units there; you’ll get more or less the same distribution.

The aerodynamics of your craft is going to be the same wherever the thrust matches the drag, regardless of atmosphere; anywhere that shares the same Reynolds Number is going to have matching performance, regardless of air density. Don’t worry about having to do custom streamlining; there’s no such need; it will be other factors that determine operating condition based inefficiencies in your design.

Thanks for the links. I may have to brush up on my math and physics, and knock some rust off that part of my brain...My last physics class was way back in 1987 at a community college. I'll see about putting some of the basics to use on my next model to give it a little better aerodynamics.

I tried several alternate layouts adn configurations, wingtips, double wingtips, midwing winglets, in wing pods, underwing pods, stub wings, delta wings...at least a dozen variations on the theme.and they al had the same issue...a complete lack of a unique visual trait. It'snot a bad look, it looks more like something from a near future action movie, not a scifi setting...the other half dozen renders of other alternates quickly found their way to the recycling bin...

Now please don't take that as me pleading artistic license... I really do try to balance sci vs fi..the design just lacked anything to set it apart...so I went with the x-foils..and a few tweaks. before I went with the build and others like it I spent a good bit of time reading and checking into various problems to see if it was even possible...when I was reasonably sure it wasn't a compleel impossible alternative I went with the x-foils, both for visual effect, and to fit in with the style of the faction I was creating it for.

 

[Reynard]

Aw, I miss the japanime wing configuration. Could also use copious amounts of sensor antennae too.

 

[phavoc]

The race I mentioned like to pull a dirty trick in atmo...they kill their gravitics and approach a target using aerodynamic lift alone. for a high altitude craft it's not as effective but at low altitude using terrain to cover the fighters approach it gives them a slight edge.

The race designs most of their atmospheric craft to be able to fly without gravitics as a general rule.it allows the to glide, or cruise on minimal power for extended periods, or make a safe entry and landing with no gravitics.

Once again that's for setting reasons they tend to have issues with their tech being extremely powerful but prone to breakdown... they build systems that are pushed to the limits of their manufacturing base So tend to lag behind other races in reliability, which means they include features to compensate.


The hypersonic dash capability is for getting to orbit or intercepting potential hostiles. the pilot can boost rapidly to sub orbital, or low orbit altitudes, use full burn without worrying about drag then either dive back into atmosphere or fire from altitude at aircraft, small craft, or starships below them.

the design cheats to get around frictional heating, by using forced air to create a boundary layer of varying profile the wing surfaces are not directly in contact with the hypersonic air flowing around them...the drag is still impressive but grav assist negates a lot of the weight of the aircraft giving it a very high thrust to weight advantage..and it is powered by a fusion reactor that could service a good sized town.

Keep in mind that as long as you are going down you can cheat a lot with aerodynamics. But, there is a limit, and if you are using starship materials to build your hull, they are going to be very heavy. And lift is a function of weight as much as speed. Though perhaps you have wonder materials that provide a lot of protection with low mass - it's the future, anything is possible!

Though sneaking in from orbit might not be so sneaky. You still will have a big thermal signature that you can't hide.

Also, with high drag you will get to a point where your additional thrust won't help you go transonic no matter what - the air will become too dense. Still, it's a game, so you have leeway in things. But something to keep in mind if you are looking at keeping within a paradigm.

 

[wbnc]

Rather than the x-wings, use upper and lower wing-tip winglets, and mount the ECM units there; you’ll get more or less the same distribution.

The aerodynamics of your craft is going to be the same wherever the thrust matches the drag, regardless of atmosphere; anywhere that shares the same Reynolds Number is going to have matching performance, regardless of air density. Don’t worry about having to do custom streamlining; there’s no such need; it will be other factors that determine operating condition based inefficiencies in your design.

Okay adhering to my principle of not disregarding advice I ask for I went to the drawing board and worked on a few ideas...

I dropped the X-foils for wingtips...then I added an ECM pod to the wingtips and tapered the waist slightly, gave it a bit more streamlined wing. Then I added the centerline weapons pod.

the results are noticeable, it has a totally different feel to it.

Now the older version looks like a Strike fighter and the newer one looks more like an airsuperiority/interceptor...

 

[wbnc]

The race I mentioned like to pull a dirty trick in atmo...they kill their gravitics and approach a target using aerodynamic lift alone. for a high altitude craft it's not as effective but at low altitude using terrain to cover the fighters approach it gives them a slight edge.

The race designs most of their atmospheric craft to be able to fly without gravitics as a general rule.it allows the to glide, or cruise on minimal power for extended periods, or make a safe entry and landing with no gravitics.

Once again that's for setting reasons they tend to have issues with their tech being extremely powerful but prone to breakdown... they build systems that are pushed to the limits of their manufacturing base So tend to lag behind other races in reliability, which means they include features to compensate.


The hypersonic dash capability is for getting to orbit or intercepting potential hostiles. the pilot can boost rapidly to sub orbital, or low orbit altitudes, use full burn without worrying about drag then either dive back into atmosphere or fire from altitude at aircraft, small craft, or starships below them.

the design cheats to get around frictional heating, by using forced air to create a boundary layer of varying profile the wing surfaces are not directly in contact with the hypersonic air flowing around them...the drag is still impressive but grav assist negates a lot of the weight of the aircraft giving it a very high thrust to weight advantage..and it is powered by a fusion reactor that could service a good sized town.

Keep in mind that as long as you are going down you can cheat a lot with aerodynamics. But, there is a limit, and if you are using starship materials to build your hull, they are going to be very heavy. And lift is a function of weight as much as speed. Though perhaps you have wonder materials that provide a lot of protection with low mass - it's the future, anything is possible!

Though sneaking in from orbit might not be so sneaky. You still will have a big thermal signature that you can't hide.

Also, with high drag you will get to a point where your additional thrust won't help you go transonic no matter what - the air will become too dense. Still, it's a game, so you have leeway in things. But something to keep in mind if you are looking at keeping within a paradigm.

There are wonder materials such as carbon fiber, carbon nanotubes, boron carbide, cubic boron nitride, aero-gels,manufactured diamond/sapphire all of which are extremely expensive at current levels of technology, but given a thousand years or so you could see them in regular use.

The sneaking in from orbit would be a pain to pull off, not something you Just do on a whim...first you have to get to orbit without being noticed. once yo are there you have to keep our descent speed down to prevent frictional heating. But if you are not moving at orbital velocity to begin with freefall can be managed to keep below the point where your hull heats up. the trick would be to try the maneuver where the other guy isnt looking. any survielance network has gaps, and those gaps can be exploited. once in atmosphere you can fly at subsonic spees ot avoid generating sonic booms, and use ground terrain to a certain degree.

the interceptors wouldnt be using those tricks as a rule, since they arent trying to sneak up on anyone, the desing is capable of aerodynamic flight as a secondary function only. Mostly to allow safe landing in the event they loose gravitic systems on ascent or entry.

 

[FallingPhoenix]

If it's got a (partial) gravitic drive, can the drive be used to provide lift? If so, do the wings allow for more thrust in atmosphere, since the drive can be focused entirely on movement when the wings are for lift? Or Is the gravitic bit unidirectional, maybe, so the wings are necessary and you can't easily zip around on an airless world?

 

[Tenacious-Techhunter]

Now the older version looks like a Strike fighter and the newer one looks more like an airsuperiority/interceptor...

That’s the direction you were trying to go in, right?

I was suggesting putting the ECM pods on the tips of the winglets, so you could get a similar “ECM Box” as your x-wings. Of course, if you like this better, I’m not about to argue whether it fits within your setting-specific ECM technology concept.

Interesting choice to forward-sweep the winglets. Very X-29. I’m not sure if it makes sense, but I like it. XD

The upshot of the Whitcomb Area Rule is that, as the wing increases in centerline axis area, the body has to shrink to compensate, to keep the same total area. Alternately, bulges before and after the wing can be used to compensate for the wings being added to an otherwise fixed fuselage shape. You should also try to change the centerline axis area as little as possible over the whole shape; a suggestion, for which, there are reasonable limits in what can be accomplished, many of them setting specific.

 

[Reynard]

Does Mongoose Traveller have builds for Interface fighters? Those would have the characteristics of an atmosphere vehicle plus gravitic capability for orbital interception. These sound like some hybrid small craft. I believe Striker, MegaTraveller and/or Fire, Fusion and Steel allowed for the design.

 

[Reynard]

"expensive due to the cost of software, and comuters they carry."

So.... how much do they charge for a ride?

 

[Tenacious-Techhunter]

If it's got a (partial) gravitic drive, can the drive be used to provide lift? If so, do the wings allow for more thrust in atmosphere, since the drive can be focused entirely on movement when the wings are for lift? Or Is the gravitic bit unidirectional, maybe, so the wings are necessary and you can't easily zip around on an airless world?

Strictly speaking, converting drag into lift is more inefficient than simply replacing lift with grav forces, if the power plant and grav drive have a better total efficiency. But he has other reasons for which he wants wings, one of which is wanting to be able to land without grav available. Maybe there’s some sort of grav drive jamming technology at play...

 

[Tenacious-Techhunter]

Aw, I miss the japanime wing configuration.

Do you mean [urlhttps://en.wikipedia.org/wiki/Canard_(aeronautics)]canards[/url]? Or Forward-Swept Wings?

 

[wbnc]

Now the older version looks like a Strike fighter and the newer one looks more like an airsuperiority/interceptor...

That’s the direction you were trying to go in, right?

I was suggesting putting the ECM pods on the tips of the winglets, so you could get a similar “ECM Box” as your x-wings. Of course, if you like this better, I’m not about to argue whether it fits within your setting-specific ECM technology concept.

Interesting choice to forward-sweep the winglets. Very X-29. I’m not sure if it makes sense, but I like it. XD

The upshot of the Whitcomb Area Rule is that, as the wing increases in centerline axis area, the body has to shrink to compensate, to keep the same total area. Alternately, bulges before and after the wing can be used to compensate for the wings being added to an otherwise fixed fuselage shape. You should also try to change the centerline axis area as little as possible over the whole shape; a suggestion, for which, there are reasonable limits in what can be accomplished, many of them setting specific.

Oh yeah, I was looking for interceptor so it was a definite step in the direction I wanted to go...will use both designs for something eventually that's why I like to get feedback. It helps the process immensely.even if all it does is force me to look at the issue from a slightly different pint of view.

Having trouble converting text into a mental image on your description one of those odd mental lapses that occur on a regular basis.

I admit the wingtip forward sweep was purely for looks in this case. The look was too nice to pass on.

Does Mongoose Traveller have builds for Interface fighters? Those would have the characteristics of an atmosphere vehicle plus gravitic capability for orbital interception. These sound like some hybrid small craft. I believe Striker, MegaTraveller and/or Fire, Fusion and Steel allowed for the design.

Interface and multi-environment craft really arent included....Hybrids arent really touched on...even the rules for streamlining are only a paragraph or two.

"expensive due to the cost of software, and comuters they carry."

So.... how much do they charge for a ride?

D'oh..... well one thing you could count on they charge for munitions expenditure if they run into a traffic issue.

If it's got a (partial) gravitic drive, can the drive be used to provide lift? If so, do the wings allow for more thrust in atmosphere, since the drive can be focused entirely on movement when the wings are for lift? Or Is the gravitic bit unidirectional, maybe, so the wings are necessary and you can't easily zip around on an airless world?

Strictly speaking, converting drag into lift is more inefficient than simply replacing lift with grav forces, if the power plant and grav drive have a better total efficiency. But he has other reasons for which he wants wings, one of which is wanting to be able to land without grav available. Maybe there’s some sort of grav drive jamming technology at play...

In the setting I developed a few years and three campaigns ago...the wings remained on craft that operate in atmosphere mostly because they are relatively cheap, you can use them for fuel tanks, and you can hang a lot of stuff on them. And if you have a really bad day you can glide, maybe not well but anything is preferable to a straight down plunge.

And yep, at least two hostile races, and one allied race have weapons that can disrupt Gravitic.They work a bit like a jump breaker missile..except they knock your gravitic offline until you can reset and restart them....not a major worry for big ships they don't tend to get into close proximity of a gravity well. The jus loose the ability to alter course,and acceleration for a short period...But shuttles, fighters, and other small craft do tend to have to worry about suddenly turning into a well-streamlined lawn dart.

Also Most missiles can track the EM noise they create, and you can hear them a long way off.

 

[Condottiere]

In theory, you could have fat wings, being extensions of the missile pack of twelve missiles, now embedded in said wings.

Pack doesn't mean it can't be linear.