Boeing is at it again

[dragoner]

As with all things, a lot of designs are going to have to be changed. While aircraft will be viable as a concept, you can't expect one made for one world to work on another.

Exactly, that is the portability. Taking aircraft from one world to another probably wouldn't happen. Plus the designs might be radically different, thin atmosphere worlds having gossamer winged aircraft that have low maneuverability due to the use of lighter materials, they would tear themselves apart similar to WW1 aircraft, banking too sharply, etc.; consequently the opposite could be true for dense atmosphere worlds. Another is the advancement of technology, better triangulated cantilevers, hybrid electric engines, plasma field stabilizers (and other control surfaces) and all that making them look quite different.

Lighter than air craft can operate in an even broader range of atmospheres, even in air as thin as mars. they would need to be built to suit but, they do not need nearly the tech infrastructure to build as grav vehicles, or the highly complex power systems needed to allow grav flight. All of this makes them cheaper alternatives, where they are able to operate...

LTA's are an interesting subject, however some different in that one is looking at displacement and buoyancy of He. Regular AC though, the subject of infrastructure is important, there has to be a certain level of population and infrastructure to design and manufacture native aircraft, and at that point the question sort of becomes how much more expensive is grav in the long run.

None says you have to operate with just one type of vehicle...

True, though most likely the stuff that will work everywhere with less maintenance will be the most popular for export/import, and it will probably go from wheeled to grav. Militarily, tracks are so expensive maintenance wise, militaries will convert mostly to grav where possible, and just use cheap wheeled transport in non combat areas in a tertiary manner.

 

[wbnc]

That is true, but all vehicles have their limitations. But on any world where humans can breath the air, aircraft are viable. even if the air is tainted, or not breathable due to gas content, or high levels of noxious gasses aircraft can operate with proper power sources.

A lot of helicopters are unable to operate at altitudes where mountain climbers can get to without carrying oxygen. So on worlds with atmospheres similar to high altitude regions of Earth, they may be competely unable to take off vertically (or would function as hovercraft, LOL!). As with all things, a lot of designs are going to have to be changed. While aircraft will be viable as a concept, you can't expect one made for one world to work on another.

Of course, that's a lot like saying boats only work there there is liquid water. It's true, but It doesn't mean that a military wont have boats just because not every world doesn't have an ocean..they use them where they can.

On higher density atmosphere woulds Roto-crft and Zeps are even better suited to operation.rotors and fans can get a better bite at lower RPM, and lifting gasses are more effective.the weaknesses and strengths balance out to a great degree

 

[Anonymous]

On higher density atmosphere woulds Roto-crft and Zeps are even better suited to operation.rotors and fans can get a better bite at lower RPM, and lifting gasses are more effective.the weaknesses and strengths balance out to a great degree

I don't understand airships but I agree that their lifting force is increased in dense air.

I think there's too many factors to make a firm statement on rotorcraft (either for or against the position stated).

It's surprising to many how severely affected a rotorcraft is by environmental conditions. Here's a pilot's chart for the R44, which is a basic helicopter, that shows how performance varies with air temperature and weight (different planetary gravity will be very important in Traveller). Notice how the lines bend abruptly near the right hand side, and how variable the performance is.

http://imgur.com/a5kSl4j

As a general note I will say two things.

The first that turbines (which power "useful" size rotorcraft) are more efficient in high altitude, thin, cold air.

The second is that rotor RPM is usually kept constant in a helicopter and set to a speed at which the advancing half of the blade remians subsonic. Thrust is controlled by angling the blades, not by blade RPM. The speed of sound in denser air is lower, which means the rotor disk must rotate slower, which means less volume of air is pushed.

I don't have the textbooks to hand to calculate whether this makes them better or worse. All I can say is that there are places on Earth where we have to modify the machines to work, and that's the planet which they were designed to operate on.

Edit: How to read the chart, in case anyone is confused. The X axis is the weight of the machine in (Earth standard gravity!). Pick a diagonal line that represents the outside air temperature (OAT). The Y axis is the altitude at which the machine can hover "out of ground effect" that is, where there is no hard surface close underneath for the rotor (say within 1 rotor diameter) to directly blast air against.

 

[Anonymous]

Tangenting a little...

Taking aircraft from one world to another probably wouldn't happen.

From which I get that if you wanted them you'd have to produce them locally. Without anti grav tech, getting an aircraft built on another world to the surface of the world you want to use from would be expensive. With anti grav tech it would most likely be irrelevant.

Have any SF RPGs gone into the kind of detail as to describe what a planet/system can and can't manufacture based on it's TL/population/government/environmental considerations?

 

[dragoner]

Tangenting a little...

Taking aircraft from one world to another probably wouldn't happen.

From which I get that if you wanted them you'd have to produce them locally. Without anti grav tech, getting an aircraft built on another world to the surface of the world you want to use from would be expensive. With anti grav tech it would most likely be irrelevant.

Have any SF RPGs gone into the kind of detail as to describe what a planet/system can and can't manufacture based on it's TL/population/government/environmental considerations?

No RPG's that I know of. The investment in infrastructure would be sizable, to design and build aircraft, so for native industry (just taking a stab at minimums): TL 6, 10's of millions population, thin atmosphere or above, not taking into consideration weather conditions, titanic storms or particulate matter, such as the volcanic pumice from Iceland that grounded a bunch of aircraft in Europe a while back.

The idea of just pulling up to a world and dropping in an aircraft is iffy, especially without any flight control network, even a small percentage of losses could be prohibitive. Grav makes it easy.

 

[Condottiere]

To be fair, a deflated blimp doesn't take up that much cargo space.

But interstellar Traveller military logistics is probably very sector concentrated, if not subsector.

 

[wbnc]

On higher density atmosphere woulds Roto-crft and Zeps are even better suited to operation.rotors and fans can get a better bite at lower RPM, and lifting gasses are more effective.the weaknesses and strengths balance out to a great degree

I don't understand airships but I agree that their lifting force is increased in dense air.

I think there's too many factors to make a firm statement on rotorcraft (either for or against the position stated).

It's surprising to many how severely affected a rotorcraft is by environmental conditions. Here's a pilot's chart for the R44, which is a basic helicopter, that shows how performance varies with air temperature and weight (different planetary gravity will be very important in Traveller). Notice how the lines bend abruptly near the right hand side, and how variable the performance is.

http://imgur.com/a5kSl4j

As a general note I will say two things.

The first that turbines (which power "useful" size rotorcraft) are more efficient in high altitude, thin, cold air.

The second is that rotor RPM is usually kept constant in a helicopter and set to a speed at which the advancing half of the blade remians subsonic. Thrust is controlled by angling the blades, not by blade RPM. The speed of sound in denser air is lower, which means the rotor disk must rotate slower, which means less volume of air is pushed.

I don't have the textbooks to hand to calculate whether this makes them better or worse. All I can say is that there are places on Earth where we have to modify the machines to work, and that's the planet which they were designed to operate on.

Edit: How to read the chart, in case anyone is confused. The X axis is the weight of the machine in (Earth standard gravity!). Pick a diagonal line that represents the outside air temperature (OAT). The Y axis is the altitude at which the machine can hover "out of ground effect" that is, where there is no hard surface close underneath for the rotor (say within 1 rotor diameter) to directly blast air against.

Explaining the vagaries of roto-craft tends to cause people to get glassy eyed. (not a dig, just an observation from experience) They use some very complex tricks to beat the air into submission....I simplified a bit....By the way have had a few hours as passenger of an R-44 owned by my flight instructor..nifty little birds.

denser air means hat ore lift can be generated at higher altitudes extending the flight envelope of the aircraft. You get better lift at night and early in the morning due to air being cooler and therefore denser....not to mention the less energetic air currents caused by heating of the ground by sunlight...

The problem with helicopters and thin air was spectacularly demonstrated in the new movie Everest, a Pilot ( and this is actual event.) managed to reach one of the highest camps on Everest to rescue a climber after a storm. During the scene I'm saying to my girlfriend...not possible...the pilot had to land at a lower altitude, and dump everything..including his copilot to reach the base camp... Having denser air to work with means the helicopter can generate lift at higher altitude than on Earth. You would loose speed due to drag as a trade off but streamlining can reduce that significantly...

The idea of just pulling up to a world and dropping in an aircraft is iffy, especially without any flight control network, even a small percentage of losses could be prohibitive. Grav makes it easy.

If aircraft have no flight control network, neither do the grav vehicles.Lack of a network isn't prohibitive to aircraft operation. I flew routinely on visual flight rules. There is a lot of open sky available, so you only need networks when traffic density means that a lot of aircraft are competing for the same airspace..

And Since you are dropping from a ship capable of selecting it's orbital velocity and "Hovering" over a planet, there isn't the need for those blazing hypersonic entries.

However there is no need to "Drop" aircraft, if your executing an assault drop then grav units, and drop pods are far more effective. which I'll freely admit to, since they are faster, more agile, and need smaller bits of sky to work properly....

But once a landing area is secured then a ship can land unload their cargo of aircraft directly to the ground. Since, at least in how I see things, Osprey types would probably be used for transport, and logistics support, not combat. There is no need for them until a landing zone is secured.

 

[Anonymous]

denser air means hat ore lift can be generated at higher altitudes extending the flight envelope of the aircraft. You get better lift at night and early in the morning due to air being cooler and therefore denser....not to mention the less energetic air currents caused by heating of the ground by sunlight...

But once a landing area is secured then a ship can land unload their cargo of aircraft directly to the ground. Since, at least in how I see things, Osprey types would probably be used for transport, and logistics support, not combat. There is no need for them until a landing zone is secured.

Seems odd when you admit that an aircraft had to be stripped down to reach a mountain top, but then go on to say that you can expect aircraft transported from world to world to continue to operate effectively without modification. As we have seen, they don't even work on Earth.

If a planet has significantly denser air than Earth, there must be a reason why. Is the gravity heavier? This will affect the how much lift the machine has. Is the air composition different? This will affect the engine's power output.

EDIT: Do not forget that one of air traffic control's functions is to redirect you around storms. I would imagine a aircraft is MUCH more senstive to those than an armor-plated grav tank is. Not just because of being thrown around, but hailstorms punch holes in aeroplanes. http://imgur.com/PhLXJxU

 

[AndrewW]

EDIT: Do not forget that one of air traffic control's functions is to redirect you around storms. I would imagine a aircraft is MUCH more senstive to those than an armor-plated grav tank is. Not just because of being thrown around, but hailstorms punch holes in aeroplanes. http://imgur.com/PhLXJxU

Though they probably have better weather radar on board then we have now and can plot a course around the storm themselves.

 

[dragoner]

The idea of just pulling up to a world and dropping in an aircraft is iffy, especially without any flight control network, even a small percentage of losses could be prohibitive. Grav makes it easy.

If aircraft have no flight control network, neither do the grav vehicles.Lack of a network isn't prohibitive to aircraft operation. I flew routinely on visual flight rules. There is a lot of open sky available, so you only need networks when traffic density means that a lot of aircraft are competing for the same airspace..

And Since you are dropping from a ship capable of selecting it's orbital velocity and "Hovering" over a planet, there isn't the need for those blazing hypersonic entries.

However there is no need to "Drop" aircraft, if your executing an assault drop then grav units, and drop pods are far more effective. which I'll freely admit to, since they are faster, more agile, and need smaller bits of sky to work properly....

But once a landing area is secured then a ship can land unload their cargo of aircraft directly to the ground. Since, at least in how I see things, Osprey types would probably be used for transport, and logistics support, not combat. There is no need for them until a landing zone is secured.

A small percentage of loss of aircraft is prohibitive to their operation. Moppy answered about flight control:

EDIT: Do not forget that one of air traffic control's functions is to redirect you around storms. I would imagine a aircraft is MUCH more senstive to those than an armor-plated grav tank is. Not just because of being thrown around, but hailstorms punch holes in aeroplanes. http://imgur.com/PhLXJxU

Transport is an interesting discussion, the Army during WW2 switched over to 100% motorized because it was easier, in particular because transporting trucks over the ocean and storing them in truck parks in the UK was far easier; horses need everyday care that trucks don't. The German Army was never more than 26% motorized, and that is in the early part of the war; the Soviet Union, lacking a proper road network in many places, after rail, the horse cart was king.

I don't want to say that 100% there won't be aircraft, but that something seems cheaper on initial purchase, doesn't mean it is cheaper over all. Traveller does have aerodynes as well, that is something, I designed an aerodyne cycle after a pic that is floating around:

Vehicle: Custom Aerodyne Cycle
TL: 8
Skill: Flyer (Rotor)
Speed: 300kph
Range: 450km
Crew/Passengers: 1+1
Cargo: 0
Open: Open
Armor: 0
Hull: 1
Structure: 1
Agility: +2
Shipping Size: 2
Cost: Cr.60,000

 

[Anonymous]

I don't want to say that 100% there won't be aircraft, but that something seems cheaper on initial purchase, doesn't mean it is cheaper over all.

There will be aircraft, but you won't be able to transport them between worlds and expect them to "just work" unless they are very basic designs.

 

[dragoner]

I don't want to say that 100% there won't be aircraft, but that something seems cheaper on initial purchase, doesn't mean it is cheaper over all.

There will be aircraft, but you won't be able to transport them between worlds and expect them to "just work" unless they are very basic designs.

Yes, I agree. For the basic designs, they might have something that is highly configurable, esp for drones or such.

 

[Anonymous]

Flight control could be a little easier to set up than it has been here. A network of small satellites put into orbit by a starship already in orbit might work better than ground based radar.

That doesn't change the lack of flexibility aircraft have in transferring between planets.

It raises questions about the aerofin option on ships and how effective it might be.

 

[dragoner]

Flight control could be a little easier to set up than it has been here. A network of small satellites put into orbit by a starship already in orbit might work better than ground based radar.

Anything that allows you to see what is beyond the horizon is good.

It raises questions about the aerofin option on ships and how effective it might be.

Embarrassingly bad? Something like that, isn't even sci-fi, it is not even a real word (it lights up my spell check). To be sci-fi, one could say "Plasma Field Stabilizers" which sounds good and sci-fi plus has some basis in real science.

 

[Anonymous]

Embarrassingly bad? Something like that, isn't even sci-fi, it is not even a real word (it lights up my spell check). To be sci-fi, one could say "Plasma Field Stabilizers" which sounds good and sci-fi plus has some basis in real science.

It's hand waved to allow small ships (or adventure class ships as they now seem to be known) to do the cool approach to a down port and pretend to dogfight... you know, the stuff that goes on in real hard sci-fi... as opposed to the boring stuff that pretend hard sci-fi does where the ships stay in orbit and you get a shuttle down if you're even allowed to set your alien disease riddled self on the planet in the first place...

How do you enforce a quarantine?

yes, that was sarcasm.

:mrgreen:

 

[dragoner]

Embarrassingly bad? Something like that, isn't even sci-fi, it is not even a real word (it lights up my spell check). To be sci-fi, one could say "Plasma Field Stabilizers" which sounds good and sci-fi plus has some basis in real science.

It's hand waved to allow small ships (or adventure class ships as they now seem to be known) to do the cool approach to a down port and pretend to dogfight... you know, the stuff that goes on in real hard sci-fi... as opposed to the boring stuff that pretend hard sci-fi does where the ships stay in orbit and you get a shuttle down if you're even allowed to set your alien disease riddled self on the planet in the first place...

How do you enforce a quarantine?

yes, that was sarcasm.

:mrgreen:

Not one but two tangents?

Plasma Field Stabilizers could be exchanged for aerofins, without really changing any rules. Aerofins make me think of Flash Gordon, "Quick, Dale, deploy the aerofins!" Then when they don't deploy, he climbs out on the wing while it's going mach 17 or something. However, ultimately it is handwaves in the idea that some ships are streamlined, the pics don't show it though, and the ones that aren't like the Mercenary Cruiser, are in fact a more streamlined design, than may others. I'm not for a new layer of complexity, usually it comes at the expense of playability.

 

[Anonymous]

Not one but two tangents?

Watch it or I'll throw in a segment too! (I thought two was pretty good for me this far into a thread that's run it's course as far as the OT goes).

Plasma Field Stabilizers could be exchanged for aerofins, without really changing any rules. Aerofins make me think of Flash Gordon, "Quick, Dale, deploy the aerofins!" Then when they don't deploy, he climbs out on the wing while it's going mach 17 or something. However, ultimately it is handwaves in the idea that some ships are streamlined, the pics don't show it though, and the ones that aren't like the Mercenary Cruiser, are in fact a more streamlined design, than may others. I'm not for a new layer of complexity, usually it comes at the expense of playability.

When I think of aerofins I think of things like this. But I was always partial to the lifting body look even tho I guess this scout has the regular vertical rear surface, not the most aerodynamic.

ETA: Bryan's 1248 scout is tho somewhat reminiscent of the X33 Venture Star so what would I know about aerodynamics? The rear of the ship isn't clear but it doesn't look like a tear drop from the pics I've seen.

 

[dragoner]

When I think of aerofins I think of things like this. But I was always partial to the lifting body look even tho I guess this scout has the regular vertical rear surface, not the most aerodynamic.

ETA: Bryan's 1248 scout is tho somewhat reminiscent of the X33 Venture Star so what would I know about aerodynamics? The rear of the ship isn't clear but it doesn't look like a tear drop from the pics I've seen.

Bryan's scout is great, I've used that very pic in my campaigns, it is also reminiscent of the X-24A; what I see are canted stabilizers on the edge of it's fuselage. If one wants to call them aerofins, meh, but those designs it's from are from the 1960's. Most of the designs are the wrong shape, they are what they are though, throwing them away would be just another waste, I'm not advocating that at all. Maybe with lifters, plasma field control surfaces, bonded superdense, etc.; designs will look way different.

 

[wbnc]

Seems odd when you admit that an aircraft had to be stripped down to reach a mountain top, but then go on to say that you can expect aircraft transported from world to world to continue to operate effectively without modification. As we have seen, they don't even work on Earth.

I never said that...of course they need to be modified. But needing to be modified doesn't make them impractical...by the way a 747 can cruise comfortably at altitudes that cause rapid unconsciousness, and temperatures well below freezing.. in most cases aircraft can operate well outside the safe environment for humans. The U2, and SR-71 both operate at altitudes of over 50,000-80,000 feet...the air up there is pretty thin...

If a planet has significantly denser air than Earth, there must be a reason why. Is the gravity heavier? This will affect the how much lift the machine has. Is the air composition different? This will affect the engine's power output.

Within the tolerance of the human body an aircraft can operate. If the gravity is high enough to make an aircraft inoperative people aren't going to be spending a lot of time there. denser air means more lift. That allows an aircraft to lift the extra weight gained due to gravity.

EDIT: Do not forget that one of air traffic control's functions is to redirect you around storms. I would imagine a aircraft is MUCH more senstive to those than an armor-plated grav tank is. Not just because of being thrown around, but hailstorms punch holes in aeroplanes. http://imgur.com/PhLXJxU

[/quote]

Not quite as accurate as you think...if o are over the radar horizon you have to have your own radar on board...Ground control networks often use a transponder mounted on the aircraft...an option most military aircraft pass on in combat areas...

yes a G-tank can handle more punishment...but its cargo capacity is limited....anything meant to carry cargo is going to be fairly frail compare to a fighting vehicle.

I would also point out that the Weather service routinely flies C-130 cargo planes into hurricanes....safely. several times a week in some cases.

 

[Condottiere]

1. Cargo space: only bring what you need immediately and what can't be manufactured locally. It would also explain why they most planets don't import their passenger transport from DaiNippon, and most likely, why their corporations opened up local factories and assembly plants for perhaps more sophisticated (and value added) components are imported.

2. Manta ray configuration: allows you to slip in jump space, ride the ether tides and glide in atmospheres.