Aircraft question

I think we established that Charis COULD build diesel engines without violating the Proscriptions. You can do it without electricity... Thus mitigating any power-to-weight issues or potential size issues.

While steam -powered aircraft are certainly possible, you really need a way to fuel the steam generator / boiler with a liquid fuel to eliminate the unnecessary weight of one or more coal shovelers.

Given what Owl knows about aerodynamics and (relatively) low-speed flight and its characteristics, I see no reason why a high-wing design with a straight wing wouldn't be feasible. High-wing and straight wing designs are inherently more stable if I remember my stability and control classes correctly. And if you limit the speed to no more than 250-300 MPH, then you can easily get by with cable and pushrod control systems as well. The issue is ensuring that the control surfaces are sized appropriately - not too big, not too small... Just right... Too small, you don't get enough control authority. Too big and you overcontrol.

Charis has the high-strength strength steels available for a "frame and fabric" design with underwing or in-fuselage hard points as well. As with all aircraft design efforts, the issue (for the initial designs) will be to not over-engineer the design - doing so will almost always incur a weight penalty. As a designer, you have to realize that the airframe will most definitely bend when you fly - a principle called aeroelasticity. The frame you design has to take this into account, realizing that you cannot build a completely rigid frame.

I was an aerospace engineer in college and spent 13 years after that flying all sorts of single engine and multi-engine military aircraft, from turboprops to turbojets. I was part of a class my senior year where we had a semester to design an aircraft from scratch. I'm quite confident that what we came up with would definitely have worked!

WeberFan wrote:I think we established that Charis COULD build diesel engines without violating the Proscriptions. You can do it without electricity... Thus mitigating any power-to-weight issues or potential size issues.

While steam -powered aircraft are certainly possible, you really need a way to fuel the steam generator / boiler with a liquid fuel to eliminate the unnecessary weight of one or more coal shovelers.

Given what Owl knows about aerodynamics and (relatively) low-speed flight and its characteristics, I see no reason why a high-wing design with a straight wing wouldn't be feasible. High-wing and straight wing designs are inherently more stable if I remember my stability and control classes correctly. And if you limit the speed to no more than 250-300 MPH, then you can easily get by with cable and pushrod control systems as well. The issue is ensuring that the control surfaces are sized appropriately - not too big, not too small... Just right... Too small, you don't get enough control authority. Too big and you overcontrol.

Charis has the high-strength strength steels available for a "frame and fabric" design with underwing or in-fuselage hard points as well. As with all aircraft design efforts, the issue (for the initial designs) will be to not over-engineer the design - doing so will almost always incur a weight penalty. As a designer, you have to realize that the airframe will most definitely bend when you fly - a principle called aeroelasticity. The frame you design has to take this into account, realizing that you cannot build a completely rigid frame.

I was an aerospace engineer in college and spent 13 years after that flying all sorts of single engine and multi-engine military aircraft, from turboprops to turbojets. I was part of a class my senior year where we had a semester to design an aircraft from scratch. I'm quite confident that what we came up with would definitely have worked!

One of the most effective fighter-bombers of the 2nd World War was made from wood. The de Havilland Mosquito had a timber frame made from birch wood.
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The steam-powered lighter-than-air aircrafts are possible and completely withing Charis current capabilities.

The steam-powered heavier-than-air aricrafts are also possible, but they are probably outside the Charis current capabilities. They couldn't "just invent" the aerodynamic: it would be almost as bad as if they claimed "Archangel Langhorne visited me and explained how to build a flying machine".

There is no particular reason why steam-powered aircraft should be harder to control. In fact, steam-powered planes were build and even have advantages - their engines were not so susseptible to the changes of air density with height

https://www.youtube.com/watch?v=nw6NFmcnW-8

Bessler steam plane, "Airspeed 2000"

WeberFan wrote:
Given what Owl knows about aerodynamics and (relatively) low-speed flight and its characteristics, I see no reason why a high-wing design with a straight wing wouldn't be feasible.

Generally the airship would be a simpler solution. The aerodynamic isn't the thing that could "just be discovered" by some particular genius.

Dilandu wrote:

WeberFan wrote:
Given what Owl knows about aerodynamics and (relatively) low-speed flight and its characteristics, I see no reason why a high-wing design with a straight wing wouldn't be feasible.

Generally the airship would be a simpler solution. The aerodynamic isn't the thing that could "just be discovered" by some particular genius.

It's not really easily explainable going from ground based travel to winged airplane flight in a single leap. No one is going to believe all the necessary discoveries happened at the same time. Or, from the Church side, didn't have some sort of demonic inspiration.

Lighter than air craft is a somewhat different story. Charis has various kinds of oil that burns; and they make a finely woven sailcloth now with their looms. Some sort of coating (like waterproofing, which they probably already have), and a hot air balloon is easily possible.

The only problem would then be one of navigation. Traditional hot air balloons are at the mercy of the wind. But there might be some temporary solutions until the groundwork for a true airship has been laid.

One might be to harness some of those large homing wyverns (or domesticate and train some of the larger, currently wild ones) to a balloon for propulsion.

Even if that doesn't pan out, tethered balloons high enough or far enough behind the battle line to be out of typical rifle range could still make a significant difference. Not only could they be used for observation platforms, but even as airborne artillery. All one would need is something to hurl explosives a reasonable distance. A arbalest, a catapult, or even a rocket with good flight characteristics could end up being more accurate than the current ground artillery; especially in rough terrain.

WeberFan wrote:I think we established that Charis COULD build diesel engines without violating the Proscriptions. You can do it without electricity... Thus mitigating any power-to-weight issues or potential size issues.

While steam -powered aircraft are certainly possible, you really need a way to fuel the steam generator / boiler with a liquid fuel to eliminate the unnecessary weight of one or more coal shovelers.

I don't think that's a problem. Charis has fuel oil from plant and sea-life origins. They currently use it for lighting. I'm sure it could be adapted to heating water in a container.

However, I don't think the transition to powered flight could be made directly in any plausible manner. Gliders, yes. Balloons and airships, yes. I think those methods would need to have occurred prior to any sort of powered aircraft; unless you want most of Safehold to begin to believe the Church's accusations of demonic inspiration.

Think a bit about it, a glider could be very useful. While most of those we see today either are towed into the air by a plane then released, or else launched from a high ground point and then catch prevailing winds; there are potentially other methods that could be utilized. For example, a steam powered catapult (similar to what launches planes off an aircraft carrier) is not all that different than the currently used steam hammers.

While a glider probably couldn't carry a lot of ordinance, it could certainly carry *some*.

OrlandoNative wrote:
Lighter than air craft is a somewhat different story. Charis has various kinds of oil that burns; and they make a finely woven sailcloth now with their looms. Some sort of coating (like waterproofing, which they probably already have), and a hot air balloon is easily possible.

The only problem would then be one of navigation. Traditional hot air balloons are at the mercy of the wind. But there might be some temporary solutions until the groundwork for a true airship has been laid.

Exactly. And the airships tended to... let's say, have more psychologiucal influence than airplanes) Especially against non-prepared superstisious enemy.

OrlandoNative wrote:[snip]

The only problem would then be one of navigation. Traditional hot air balloons are at the mercy of the wind. But there might be some temporary solutions until the groundwork for a true airship has been laid.

[snip]

Not the only problem – weather would be another. I seem to remember reading about some pretty vicious storms on Safehold, and balloons are very susceptible to high winds. Airships will be less so, but they are pretty slow, and unless one of the inner circle is on board to receive advance warnings of adverse weather, a storm is likely to be on them too quickly to be avoided. Weather was thought to be contributory to the crash of the R101, and the USS Akron broke up in a thunderstorm.
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I don't see any reason that some nerd from the royal college couldn't discover the secrets of pitch and yaw by experimentation. That, after all is what the Wrights did over several years of part time effort. It is not really all that far beyond what Charis' current capabilities are. Also, beyond the notion of the idea of flight, I don't see a whole lot of direct connection between balloons and heavier than air winged flight. Kites are much closer.

Don

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OrlandoNative wrote:Even if that doesn't pan out, tethered balloons high enough or far enough behind the battle line to be out of typical rifle range could still make a significant difference. Not only could they be used for observation platforms, but even as airborne artillery. All one would need is something to hurl explosives a reasonable distance. A arbalest, a catapult, or even a rocket with good flight characteristics could end up being more accurate than the current ground artillery; especially in rough terrain.

Tethered balloons are catastrophically BAD platforms for artillery. In fact I am not aware of ANY serious attempts to use balloons as ordinance delivery systems. Observation was strictly the way to go with military ballooning.

Problems in using a balloon as an ordinance platform are in no particular order are:

* Lack of overall lifting capability
* Inaccuracy due to lack of stable firing platform. They are worse than a ship in this regard and unlike aircraft or zeps do not have engines to provide orientation and thrust.
*Buoyancy changes as ordinance is expended
*Reaction forces - for every action there is an equal and opposite reaction. The force required to launch any decent sized projectile a mile has a massive kick
* Sitting duck for ground fire.

They are also most useful in set piece actions such as sieges or static trench warfare as getting them set up and filled with either hot air or hydrogen is a complex technical process much at the mercy of the weather.

It should also be noted that aircraft delivered ordinance is inferior to tube artillery until some time about WW2 for a variety of reasons. The big advantage of aircraft is that they increase the range and don't have the same problems of trailing behind the leading infantry as to be out of range (this is a big issue even with modern mechanized warfare.