Pre WW1 possibilities

[hagaricus]

Can we allow complete fantasy here? If so this is a scenario I keep coming back to:

You have fallen through a timewarp.

It is April 12th 1912 and you are on a ship in mid-atlantic.

Which way it is going is up to you.

You get caught as a stowaway and put to work doing menial labour on board.

You realise the Titanic is about to sink, and manage to engage many of your shipmates in quite large bets on it sinking.

You walk off the ship in the country of your choice a moderately rich person, and by way of your knowledge of the future, manage to increase this wealth to the point that in september 1912 you can start developing an aircraft.

What do you build?

 

[riggerrob]

I start with wire-braced monoplanes with nose-wheels.
My second generation is strut-braced monoplanes and my third generation are cantilever monoplanes with thick, wooden D-spars.
Early on I arm my planes with machineguns firing through the PRSUs of inline V-engines.
Tricycle gear from the start.
Center-of-gravity AHEAD of the center-of-lift.
Differential ailerons.
Balanced tail surfaces.

 

[hagaricus]

So, having pondered through this many times, I always end up with a low-wing cantilever monoplane of wood construction with fixed, faired gear & an open cockpit. ....

The back story is intended to set clear parameters, but that leaves the question of whether to be limited to materials & technologies that existed at the time, or to allow oneself to speculatively improve and invent.

The big issue is engine choice. If limited to existing engines then the choice is between rotary or inline watercooled, when what I really want to do is perfect the aircooled radial early to get more power. This sometimes leads me to a pusher-puller design with 2 rotaries and a twin-boom tail...

Ideally I want to skin in plywood, although fabric is the lighter option..

As for guns, I'm torn between putting effort into making a belt-fed design lighter & more reliable so it can sensibly be placed in the wing, outside the propeller arc, or whether to focus on interruptor gear. Either way, 2 guns in a modern, rimless rifle caliber such as 30-06 is the intended armament.

I'm intrigued by Riggerrob's focus on tricycle gear, as I'd go for a taildragger design, also not sure what PRSU's are in this context, but I take it this is a way to fire through the hub without interruptor?

Musing on...

 

[riggerrob]

So, having pondered through this many times, I always end up with a low-wing cantilever monoplane of wood construction with fixed, faired gear & an open cockpit. ....

The back story is intended to set clear parameters, but that leaves the question of whether to be limited to materials & technologies that existed at the time, or to allow oneself to speculatively improve and invent.

The big issue is engine choice. If limited to existing engines then the choice is between rotary or inline watercooled, when what I really want to do is perfect the aircooled radial early to get more power. This sometimes leads me to a pusher-puller design with 2 rotaries and a twin-boom tail...

Ideally I want to skin in plywood, although fabric is the lighter option..

As for guns, I'm torn between putting effort into making a belt-fed design lighter & more reliable so it can sensibly be placed in the wing, outside the propeller arc, or whether to focus on interruptor gear. Either way, 2 guns in a modern, rimless rifle caliber such as 30-06 is the intended armament.

I'm intrigued by Riggerrob's focus on tricycle gear, as I'd go for a taildragger design, also not sure what PRSU's are in this context, but I take it this is a way to fire through the hub without interruptor?

Musing on...

Propeller speed reduction units were the norm by World War 2. By 1939, most engines turned faster than was efficient for propellers, so they needed to be geared-down to reduce propeller tip speed. IOW If you try to turn a propeller at a tip speed of more than Mach 0.8 it produces far more noise than thrust. So you need to slow the propeller tip speed below supersonic to convert horsepower into thrust.
Since a PSRU can be built with a hollow shaft, it allows you to run a blast tube up the middle. Blast tubes were manufactured for guns ranging from 8 mm to 37 mm (Bell P-39 Airacobra). 8mm was sufficient for damaging WW1 airplanes made of wood and fabric, but 20 mm or 30 mm was needed to destroy WW2 airplanes.
Since a PSRU allows you to offset the propeller shaft from the crankshaft, it allows you to install a gun firing through the center of the propeller (motor-kanon in German). Starting during WW1 Hispano-Suiza laid auto-cannons between the cylinder banks (V8, liquid-cooled engine) and fired it through a propeller shaft that was raised above the engine's crankshaft.

 

[riggerrob]

So, having pondered through this many times, I always end up with a low-wing cantilever monoplane of wood construction with fixed, faired gear & an open cockpit. ....

The back story is intended to set clear parameters, but that leaves the question of whether to be limited to materials & technologies that existed at the time, or to allow oneself to speculatively improve and invent.

The big issue is engine choice. If limited to existing engines then the choice is between rotary or inline watercooled, when what I really want to do is perfect the aircooled radial early to get more power. This sometimes leads me to a pusher-puller design with 2 rotaries and a twin-boom tail...

Ideally I want to skin in plywood, although fabric is the lighter option..
.....

A wide variety of woods and skilled craftsmen were available during WW1. The technological limitation was glues that were stronger than the wood and durable enough to last a year or two. Anthony Fokker pioneered all-wood cantilever (no bracing wires or struts) wings during WW1. Inter-plane struts and wires were little more than formalities on Fokker's later biplanes and triplanes. Fokker used glued box spars surrounded by ribs that defined the external airfoil shape.
The next step (1920s) was wooden D-spars that glued the outer leading edge to a deep main spar to carry most of the lifting and torsional loads. The rear spar primarily served to mount aileron hinges. Aft of the main spar, most wings were still only covered with fabric.

You see similar construction methods on 1920s vintage deHavilland airplanes with solid wood longerons running the full length of the fuselage. The front and cockpit were fully sheathed in plywood, while the aft fuselage had a few (solid wood) vertical braces with plywood limited to gussets at joints. Later, they replaced most of the aft fuselage bracing wires with internal wooden diagonal struts.

 

[Deltafan]

https://www.secretprojects.co.uk/threads/burgess-dunne.29266/post-404288

 

[Archibald]

Motorjet technology, funding Henri Coanda.

 

[Bottleship]

In fact, 1912 is too little to change anything before the First World War. And, I think that it will be much more useful to try to hasten the victory of the Entente (for example, by strengthening the army of France or Russia). If the Entente wins not in 1918, but in 1915 or 1916, this will immediately remove Nazi and communist dictatorships from the history of the 20th century - Nicholas II said that Germany should be divided into zones of influence in order to avoid revanchism, therefore, about the Third The Reich can be forgotten, and without the protracted First World War there will be no communists in Russia, which means they will not be anywhere. Well, or, if you are a German, you can warn Wilhelm that the war will be very difficult, and how many shells will be needed, and then you will live in a world where Germany began to own all the resources of Eurasia and hundreds of millions of slaves I doubt that anyone will resist the temptation to make their country greater in the present by changing the past, and therefore it can hardly be considered that anyone will seriously develop airplanes if they fall into the past.

 

[Cjc]

Personally I would be working on a light machine gun instead, much more useful then anything I could do with a plane.

 

[Apophenia]

Agreed. Knowing that trench warfare is coming, tracked AFVs would be an obvious focus. But, hey, airplanes are fun ...

My starting point is riggerrob's suggestion of a gun firing through a hollow PSRU gearbox and propeller hub. Rather than adapting an infantry gun, I would use a purpose-built, engine-driven machine gun (similar to the weapon originally envisioned by Franz Gebauer in Austria-Hungary). [1] Akin to modern 'chain guns', stoppages are avoided by simply ejecting any mis-fired cartridges. More on those cartridges to follow.

I would avoid radical airframe layouts. Many a project has run afoul of officialdom for being 'not according to established practice'. So, my starting point would be the structural techniques of the Royal Aircraft Factory's B.E.2 biplane. The wings would have ailerons (like the May 1914 B.E.2c) but be shortened to about a 28 foot span (and reduced to two bays). The fuselage (compared with the B.E.2) would be shortened (to ~22 feet) and deepened for slightly better aerodynamics. The aim of these changes would be producing an interceptor/scout with reasonable manoeuvrability and a top speed of more than 90 mph.

My powerplant engine started point would be the Wolseley 80 hp (aka Type B) of 482 cid. [2] Obviously, this engine is too small and under-powered but it already had a propeller reduction gear and was water-cooled (getting around the reputed operating inefficiencies of the air-cooled Renault 70 hp/RAF 1, et al). The modified V-8 would retain the Wolseley's 5.51-inch stroke but have its bore increased to 4.5-inches to produced a 700 cid engine. The result would be roughly equivalent to the Hispano-Suiza 8B (HS 36 model) but appearing a few years earlier. The most important difference in this what-if engine would be its revised gearbox with a power take-off to drive that motor-gun.

As mentioned, the key emphasis of the motor-driven machine gun would be avoiding stoppages. And avoiding stoppages pretty much eliminates the tapered and rimmed .303 British service round from consideration. The trick would be convincing officialdom to adopt a new cartridge for 'air use'. Had the British Army adopted the rimless .276 Enfield round earlier, problem solved. But they didn't. So what contemporary British-made cartridge might make a plausible substitute? Just for fun, I'm going to propose a British-made, rimless 'big game' cartridge for our motor-gun.

The cartridge in question is the .404 Jeffery (aka .404 Rimless Nitro Express). [3] The rationale for this 10.26 x 73 mm round in a motor-gun is that the cartridge has a "manageable recoil" (compared with other 'big game' rounds) and a well-tapered shoulder. The latter's shape reminds a bit of the 'Short Solothurn', so I'm assuming this feature would aid in ensuring ease of feed and extraction. The object here is greater range and hitting power than German defensive weapons. Kynoch was the main producer of .404 Jeffery for the civilian market. [4]

The result of all this effort would be a Royal Flying Corps interceptor capable of denying access to German recce aircraft (the Albatros B.I, for example, having a top speed of only 65 mph). As a time-traveller, we also know that our design will be slightly faster than the 87 mph Fokker E.I Eindeckers anticipated for 1915. But if Germany lacks effective 'eyes in the sky', might we dare to hope for an Allied victory by Christmas?

Attached: A sideview of this hypothetical interceptor (with due apologies to Ronny Bar for mangling his lovely B.E.2c image).

_________________________________________

[1] When is finally emerged, Gebauer's twin-barrelled 1918.M was engine-driven but had to be synchronized.

[2] The sole B.E.1 of 1911 had been powered by an 'inherited' Wolseley 60 hp.

[3] Other British cartridge alternatives might be Kynoch's .375 Rimless Nitro Express (RNE) - aka 9.5×57mm Mannlicher–Schönauer. That cartrdige was designed at Westley Richards and first produced by Eley in 1908. A slightly more radical idea would be to 'neck out' the .280 Ross - aka .280 Rimless - target round into ~10 x 66 mm (instead of 7 x 66 mm).

[4] Based upon Kynoch's wartime production of other calibres, I'm assuming that their production of a '.404 Ball' for military use could be scaled up fairly quickly.

 

[riggerrob]

Dear Apophenia,
Great suggestions about airplane-mounted guns.
An engine-driven machinegun could eliminate most of the problems with adapting "ground" guns to fire through propellers. Props turned at 2,000 to 3,000 rpm roughly 4 to 6 times the rate of fire of ground-based MGs. If the firing pin is linked to the camshaft, you could reduce the rate of fire to more like the 600 rpm that was fashionable on ground guns. By WW2, they increased RoF to more like 1,000 rpm on aircraft guns.

.404 Jeffery/Rimless Nitro Express is a good starting cartridge, considering that Mauser and Browning only developed their anti-tank and heavy machinegun ammo late in the war.

Your cleaned-up B.E.2C. looks a bit like the successful S.E.5A. flown by aces like Billy Bishop.
Your greatest challenge is the low-power engine. Low power forces you to use the lightest possible airframe. The lightest possible airframe has the most wires. All those wires seriously slow any airplane.

So the next challenge is to develop plywoods and glues durable enough and early enough to allow you to build cantilever wings (e.g. D-spar) as early as possible. Cold-molded, plywood, cantilever monoplanes dominated sailplane competitions until the introduction of fiberglass during the late 1950s. Early fiberglass airplanes were heavier and smoother than plywood. Only since the turn of the century have carbon-fiber molded airframes became lighter than plywood. To save weight, your wings will probably be skinned with plywood for the first third of the chord, then fabric covered aft of the main spar (see late war Fokkers).

 

[robunos]

I think, rather than developing specific items, I would do what Professor Junkers, or the Soviets would later do. I would set up and fund a research organisation, to develop the needed technologies.
Using the example posted above, a geared engine is required. Okay, you say, but in the Real World, the only geared engine to enter widespread service was the Hispano-Suiza, and even that suffered problems with it's reduction gears, as the required metallurgy was really beyond the achievable state of the art. Only those engines built by Hispano-Suiza themselves were ever really acceptable, and one sub-contractor, ironically Wolseley, had so much trouble that they re-designed their version of the engine into a direct-drive version, the Viper.
Likewise, when Junkers first flew his J.1, it's performance was below par. Rather than use the prevailing method of 'Experimentation' (aka Trial and Error), Junkers built a wind tunnel, and recruited staff to operate it, and analyse the data. This lead to the realisation that the problem was with the J.1s thick wing root, necessary for structural reasons. By moving the wing to the low position on the fuselage, and thinning it somewhat, the lost performance was restored.
So, my research organisation would have the following departments; Aerodynamics, to determine the optimum form for my aircraft, Aerostructures, to develop the materials and methods necessary to construct it successfully, Metallurgy, to develop the materials needed for a suitable engine, as well as other components, including weapons, and Propulsion, to develop the engine, making use of the advances in Metallurgy. Some aspects would cross these boundaries, such as propellers . . .

cheers,
Robin.

cheers,
Robin.

 

[T. A. Gardner]

I'd stick with what I know. Hook up with someone like Andrew Carnegie and introduce him to how to make high strength aluminum alloys that have good corrosion resistance. Then show him how vacuum remelt of steel improves its strength and corrosion resistance.

Inventing plywood that is moisture resistant using phenol formaldehyde glue would be another route to go, particularly if you combine it with using the proper woods. The big trick is getting the thin sheets of ply to make it from in mass. An alternative would be to go straight to OSB instead, cheaper just as strong, and easier to make.

I could see doing a motor jet engine, but only if you could simultaneously "invent" flame spray technology (it's around starting in 1910 in Switzerland) and had stainless steels available. These are necessary to give the engine good life. It would require a good turbine, so I'd hunt down Stanford Moss for that.
You show how to flame spray alumna powder onto a metal surface to form a barrier to heat, and how to use some bleed air to cool the exhaust and combustion chambers of the engine. Kerosene is widely available as a fuel.

That would also jump start exhaust driven turbocharger development.

Another area to work on would be insulation for wiring. This would have applications in the civilian world in general and production of ones that work at high altitude would be vital to aircraft production eventually.

 

[robunos]

Can you form compound curves in OSB ?

cheers,
Robin.

 

[T. A. Gardner]

Can you form compound curves in OSB ?

cheers,
Robin.

No, but for many things, like ribs and stringers OSB would be fine. That limits the need for more expensive plywood to be used.