I have so many projects that have come along that I say. OOOh, I want to build that one! (like most of us I think). On the Latest Episode (Ep 49) of the Aviation RC Noob Podcast, Joe (my co-host) talked about some of the earliest flights off of water. And he reached deep into the way-back pocket and found a plane pre-dating the wright brothers by nearly 30 years!
THE DRACHENFLEIGER
Who invented the aeroplane? If you said “the Wright Brothers” you’re… kind of correct. The Wrights were certainly first to achieve sustained flight – or at least publicize it – but it’s often easy to forget that when a new technology appears, it’s usually because a lot of people were all already working on it independently in a kind of innovation race. We remember the Wright Flyer as the “first airplane”, but theirs wasn’t the only design being worked on at the time. And, in fact, there were flying boat designs being patented as far back as the 1870s.
One was the project of Austrian engineer Wilhelm Kress whose craft was the magnificently named “Drachenflieger”, or “dragon-flier”. At the very start of the twentieth century, Kress had conducted some promising taxi tests on a lake, but he wasn’t able to afford the more powerful, lighter engine he needed to achieve sustained flight. And sadly, in 1901, the lightweight and fragile Drachenflieger suffered severe damage while operating on the lake, broke up, and sank.[1]
Kress had originally intended to have an engine specially built, calculating that he needed 37 kW from an engine weighing not more than 220 kg (475 lb). When the cost of this proved prohibitive, he purchased an automobile engine already in production which had an output of just 22 kW (30 hp) but weighing nearly twice as much as Kress' calculations allowed for. [3]
The major innovation of the Drachenflieger was its use of a control stick for its flight controls. Kress had invented the control stick during the design process, and initial tests were favorable. He tested the craft at a reservoir outside Vienna, and it could successfully maintain flight while taxiing. The problem was the engine. Kress didn’t have the money to have an engine specifically built for his craft, so he bought an automobile engine instead. Unfortunately it weighed twice as much as he calculated for, and this extra weight prevented the Drachenflieger from achieving liftoff. He was able to achieve a series of hops along the water surface, but he was unable to achieve sustained flight. Kress then returned to testing while taxiing in order to refine the design.
The Drachenflieger afloat
Still, it’s not hard to imagine that, had he had the extra funds he needed, or if that damage hadn’t occurred, maybe we’d be remembering Kress’ Drachenflieger as the world’s first heavier-than-air powered flight. [2]This sketch (possibly a patent sketch) show dimensions. *it reads ~51m rudder to tip* using this and the 3-view (patent sketch?) below, we can extrapolate the wingspan to be approximately
- Wingspan: 120' (~40m)
- Length: 150' (54m)
- Height: (Propellers) 12m, likely sat 11m proud of the water
- Crew: One pilot
- Gross weight: 850 kg (1,870 lb) [4]
- Powerplant: 1 × Daimler automotive engine , 22 kW (30 hp)
[1]https://mentourpilot.com/flying-boats-where-did-they-go/
[2]https://www.onverticality.com/blog/wilhelm-kress-drachenflieger
[3]https://en.wikipedia.org/wiki/Kress_Drachenflieger
[4] Originally appeared in Scientific American, 84, March 2, 1901, p. 137, reproduced here
Project Goal:
Build a Quick Fun Slow Flyer and test if the idea would have worked. then change to today propeller and see if the efficiency increase (like those developed by the Wright Brothers propeller innovations) could have saved the project.
Plans:
Below are plans created by Wilhelm Kress of the 1901 flyer:
Attached to the picture below is a PDF of the Alpha Plan set (5 Pages). ATM there are no labels so build at your own risk. If you do build this I will try and help you, but it is build at your own risk for now.
Build Summary: (Detailed Build log below)
Currently I am working on the plans. I first thought Scale it to 60" Wingspans... then decided to pay attention to the chord length and scaled it a little further, so they are 8,10, and 12" chords. This means the 3 wings take up 3 sheets of Foam, the rest is pontoon, tail/rudder, and structure.
As the props will be Approx. 6" diameter, I think I should be able to 3D print a motor support and make it 1806 motor supports. I will then change the custom props to a traditional 6x3 or 6x4.5E props.
(doesn't it look vaguely like the USS enterprise?)
Maiden Flight:
Glide Test:
[Success Here]
Improvements/take-aways for future builders:
[pending successful flight]
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( I might have the wing order off.)
