[STOCK] Westland Wyvern S.Mk.4

[EvenFlow]

 

 

INTRODUCTION

 

Hi everyone. Ever since I've created my replica of the Soviet Tu-95K bomber with stock parts I have been thinking about taking the idea of stock propeller plane replicas further. And after a few months of hiatus, here is the fruit of this ambitious plan. This is one of the very few replicas of this magnificent superprop attack plane from the 50s in KSP, and, as far as I am aware, the only one created with solely vanilla parts. The propeller has some limited functionality in terms of actually propelling the plane, but is mostly here for the looks. The majority of power is provided by the exhaust pipes on the sides of the airplane which isn't that much of a stretch in terms of realism. The real Wyvern also gained some additional thrust from it's turbine exhaust, so it's just the matter of scale and proportion here.

This replica doesn't only approximate the real deal's looks and proportions, but also comes very close in terms of performance even in stock aerodynamics model.

 

 

PERFORMANCE

 

Here are some stats gained from preliminary testing. Real life performance figures are marked in red.

• Top speed: 604km/h vs 616km/h
• Rate of climb: Varies with altitude, approx. 15-16m/s loaded with fuel vs 11m/s stated on Wikipedia (Couldn't access historical sheets but i am pretty sure it is higher than that especially at low altitude)
• Loaded weight: 10.975kg vs 11.113kg (This is MTOW for the real Wyvern so the loaded weight is probably even more accurate)
• Turn time was hard to judge correctly, partly due to unclear testing circumstances and partly due to the fact that KSP does not model compression correctly, thus making planes vastly overperform at high speed turns.

At mid to low speeds in range of 280 to 360km/h the craft turns pretty much as you would expect from an 11 ton attack aircraft. In short - it will not pull 20Gs at 80m/s.

 

FEATURES

I've tried to model the most vital features of the real aircraft into this replica. The Wyvern S4 comes with:

1. Correctly distributed and modeled flaps, activated via Action Group 1

2. Openable engine cowling which allows the pilot to take a look into the engine, which apart from it's mechanism is semi-realistically detailed with some shenanigans. It is toggleable via Action Group 2

3. Retractable tailhook for carrier landings. It's not like you will be performing many of those in KSP though sadly. Activated through Action Group 3

4. Functional, spinning, fully stock propeller assembly. The instructions on how to get it to work properly are attached further below.

5. Plenty of little details such as correctly placed antennas, Hispano cannon props in the wings etc.

 

 

HOW TO FLY:

1. Pre-flight procedures and startup

Before taking this turboprop cow to the skies there are some things you need to do.

• Idle the throttle and engage brakes. SAS needs to be off.
• Stage the first stage. The ring securing the propeller in place will come off and your control will be redirected to the propeller.
• Start up the propeller. Hold down ALT and either Q or E. Hold the key until the roll indicator in the bottom left corner of the screen will reach it's limit. Remember to have SAS disengaged in this stage if you want the propeller to work. SAS, along with neutralising set roll trim with ALT can be used to stop the propeller post-flight.
• Switch back to the main vessel, engage the SAS (although the craft is perfectly flyable without it of course) and disengage the brakes. After the propeller has started rotating sufficiently quickly you can add throttle and begin the takeoff.
• The plane will take off by itself after reaching approx 60m/s. Tailwheel and rudder can be used to counter the torque generated by the engine which can be felt while the plane is low on speed (this also applies to real life propeller engines)

2. Flight

• Flying the Wyvern is very easy. The plane is stable at any speeds above it's stall speed (which sits at about 40m/s), will reach speeds of up to 170m/s (and over 230m/s in a dive), and the fuel will last for ages.
• The drop tanks are expended first, after they run dry you can jettison them with staging.
• Turning is safe at any speed in it's flight envelope, but due to compression not being modelled it will lose speed in high speed turns rather quickly. Mild turns are advised if you are planning to keep your speed up.
• Just like in real life, roll rate of this plane gets rather sluggish when your speed is too low. Keep an eye on your speed during tight turns to prevent stalling.
• Optimal climb can be achieved at approx 80m/s TAS at most altitudes.

3. Landing

• Landing the Wyvern is relatively easy due to it's low stall speed and flaps doubling as very effective airbrakes.
• To drop your speed quickly, feel free to pop the flaps. Get your speed down to about 70m/s, retract the gear and lower the throttle. Watch out not to come in nose-first, since this could damage your propeller. Engage brakes after touchdown, use the tailwheel to taxi into a desirable position. Engine can be turned off with methods described in "Pre-flight procedures and startup" section.

 

Creating this plane was a great experience. I hope you will enjoy flying it as much as I've enjoyed building it.

 

DOWNLOAD LINK

https://kerbalx.com/EvenFlow/Wyvern-S4

Updated on 22-07-2017, V1.2

CHANGELOG:

1.0 - Inital release

1.1 - Minor tweak to the bottom part of the cowling which made the propeller assembly spontaneously detach when jumping to the craft from more than 250m, wing strake is now attached to the wing itself which prevents it from clipping awkwardly while pulling high-G maneuvers.

1.2 - Tweaks done to the page itself, part of a revamp of all of my noteworthy older creations

 

Here's a little preview GIF too, as requested.

 

Edited July 22, 2017 by EvenFlow

[YoeriCookie]

Think you can upload any GIFs? And what's the partcount?

Edited July 18, 2017 by YoeriCookie

[EvenFlow]

I could try uploading GIFs, sure thing. The part count is pretty manageable, sitting at 128 parts. This could be stripped to sub-100 if i were to strip this thing off it's details probably though.

EDIT: Preview GIF added!

Edited July 19, 2017 by EvenFlow

[selfish_meme]

I believe there is enough room to make the prop at least contra-rotating, if not power the plane entirely from the propellers, that should make it handle better since currently the air stream would hit all blades at the same angle disrupting the handling off the aircraft.

[EvenFlow]

With enough tweaking there could possibly be some space left for another mechanism to allow for a contra-rotating propeller, but there are two things that make it unlikely to actually happen. First, if the propeller was to actually provide any considerable amount of power to the airframe, there is the problem of elevons visually "disconnecting" from the shaft itself after reaching high RPM which - while increasing functionality - decreases the overall value of the craft as a replica. Second of all, additional mechanisms would require a complete engine redesign, during which some of the visual smoothness of the airframe would certainly be lost. My doctrine of building propeller aircraft differs vastly from, say, Azimech's. He builds brilliant actual propeller engines, but just look at the size of most of his stuff. When I'm building a replica I want it to look and perform as close as possible to the real life counterpart and due to KSP having sketchy (at best) aerodynamics, I sometimes have to sacrifice some of the mechanical fidelity. I would love to make a compressor-driven turbine with functional fans, trust me. It's just that KSP won't allow me to do that in scale this small and with the current physics engine.

 

EDIT: If anyone would like to try making this thing actually run on it's propeller and even utilizing contra-rotating props to negate torque then feel free to do any modifications you like and post them if they are successful. Would be incredible.

Edited July 19, 2017 by EvenFlow

[selfish_meme]

It's definitely doable to have contra-rotating propellers with thermometer rcs bearings, they can be tiny. Powering it (beyond simply spinning) by propeller inside your plane would probably be limited to electric. Though I can make a small chopper with 2 junos so it may be doable, the engine and prop compartment is quite long.

[EvenFlow]

Powering the prop would probably be as simple as adding more SAS units for torque and tweaking the prop pitch for optimal performance i suppose. The visual detachment of the propeller blades is what puts me off really . I might actually try to make a proper prop powered replica of a longer-nosed fighter such as the german Dora variants of the 190.

Also, does anyone knows whether rigid attachment helps with keeping the blades attached to the assembly?

Edited July 19, 2017 by EvenFlow

[Bubbadevlin]

Cool plane!

[EvenFlow]

Fixed some minor bugs assosciated with switching between distant craft mostly.

Also, here is a little sneak-peak of what is to come next.

 

 

Stay tuned.

[EvenFlow]

Layout updated, Fw-190D, F-15C and MiG-29A coming up in a second.