I'm reposting the D.I to include some more details and to clear up some misconceptions Madman presented.
Dehnert Adderbolt D.I (AvDD.I)Following the adoption of the 160 hp Dehnert 9B radial engine and the incoming gearing of his company for its production, Stefan Utrecht set out to design an iconic aircraft to fit the powerplant and bring much-needed prestige to the Kaiserliche Luftjäger, of which his colleague had now become a member. The aircraft needed to be a noticeable improvement over the arguably outdated Motte - something on-par with vessels showcased in the European theatre, but distinct, so as to win the skies for the Empire.
Stefan thus tasked Andreas with designing a single-engined open-top single-seat aircraft, calling it the Dehnert Adderbolt. The result was a bit more developed - made to be a sturdy wooden monocoque aircraft, aerodynamically designed to maximize top speed and maneuverability, featuring a high-set front wing and low-set rear wing supported with a thicker wing root and a few wires, fixed tricycle undercarriage, and a pusher propeller, with the engine in the rear of the fuselage and the pilot sitting in the front of the fuselage - armed with not one, but two fixed 7.62 mm GL-11s. The wings would thus be arranged in this way to reduce the overall span of both wings (and the tail is thus removed, in favor of placing the vertical control surfaces on the wingtips and making full use of the two wing surfaces for control), increasing the craft's maneuverability dramatically while making up for it with the added lift afforded by the Adderbolt arrangement. Further perks would ostensibly be the shorter take-off and landing runs this craft would face and the impossibly difficult task of stalling such a machine, making the aircraft more forgiving to high AoA maneuvers and saving the lives of numerous pilots in the process. To further aid in the craft's controllability, ailerons are to be developed so as to keep pace with the enemy and placed on both wings. Having seen the promise of the design, Stefan filed the patent for the Dehnert Adderbolt D.I* with the Luftjäger and awaited the reward that was sure to come.
*He liked to call it that, as the name AvDD.I / Dehnert Adderbolt D.I sounded better to his ear - the fact the plane differed from ordinary biplanes was ignored on Stefan's part
Design Proposals
Dehnert Adderbolt D.I (AvDD.I) (1): Thanik
Dehnert D.II (AvDD.II) (0):
Dehnert D.III (AvDD.III) (0):
Dehnert D.IV (AvDD.IV) (0):
Project R&D
Invest once and rush progress on the Dehnert 9B (1): Thanik
Invest once in the Dehnert 9B (1): Thanik
Do not invest in the Dehnert 9B (0):
Advantages due to the tandem wing:
1. The division of lift between two wings and the prospect of achieving an increased overall Cl (lift coefficient) makes it possible to restrict the wingspan (
reduce the aspect ratio), thus
elimination weight and increasing structural strength while also
boosting maneuverability. This also leads to the elimination of the conventional tail and the concentration of the power plant weight near the CG, resulting in considerable reductions in both length and structural weight, which, in combination with the above, should also result in increased maneuverability.
2. Both foreplane and aftplane would contribute to total lift and consequently, the parasite drag associated with a conventional tailplane would be eliminated - this often amounting to as much as 10% of the total drag of a clean aircraft.
3. With the conventional wing-tailplane arrangement, the nosedown pitching moment associated with the center of pressure movement due to increased incidence calls for maximum negative lift from the tailplane at the very moment when the greatest overall lift is desired, but with the true tandem-wing arrangement the lift of the two planes would be additive and backward movement of the CP would call for increased lift from the leading plane to maintain trim. Translated to human language this means that if the angle of attack increases the place of the lift force shifts more backwards. Conventional airplanes need to compensate this moment (generated by the lift force being more backward from the CG) with an increasing downward force at the tail. Because higher AoA are used during landings, this is not ideal. When landing you need to get as much lift out of your airplane as it can get at those lower speeds. Tandems also get this extra moment, but they can compensate it by creating MORE lift on the front wing.
Advantages due to the pusher propeller:
1. By locating the engine amidships to drive a pusher propeller, the pilot could be positioned in the nose and thus provided with the
perfect, unobstructed view (as much as possible, at least). This position of the engine brings the center of gravity further back, making the aircraft more maneuverable (at slightly higher speeds - it's worse on the ground and shortly after take-off, but that's minimized with this setup)
2. A pusher may have a shorter fuselage and hence a reduction in both fuselage wetted area and weight.
3. Pushers had advantages of pushing the wings and control surfaces through undisrupted air and that gave enough advantages that the a lot of pusher designs were put forward. A pusher would have superior cruising speed and better wing loading because it flew through undisturbed air, and control would be easier to retain.
4. Reduced wing icing (important in the winter!).
Other reasons why I believe this setup is superior to Madman's proposals is that they:
It should be both cheaper than the one with wing mounted guns and retain a reasonable pricetag approaching MAYBE 5/1 and more maneuverable than a tractor configuration while possessing higher accuracy due to having (two!) forward mounted guns. It's also the least complex of the proposed tandems due to trying the least things, but that boils down to Madman's wing mounted guns for the most part, I believe.
More here:
https://www.brighthub.com/science/aviation/articles/64838.aspxhttps://www.quora.com/What-are-the-advantages-and-disadvantages-of-a-propeller-at-the-back-of-the-fuselage-of-an-airplaneTho I've also found some stuff suggesting otherwise, but I think that - as proposed - these advantages hold.
Author
Topic: They Who Dare: The Empire of Schwarzes Holz - Kaiserliche Luftjäger (Read 22559 times)