The Legacy
In the edes of the year 2025, we are calling an official end to the Fluglicht project. This is sad, but also the perfect time to reflect on the last 7 years and work out what we have learned! An incredible amount of work has flown into the project and many people will be sad that it ends. But it has to be done, as we have reached the limit of our will to push on and found no-one willing to give us the necessary funds. Nonetheless the idea of human birdflight is immortal. And as we have figured out the way, it is just a matter of time till it will eventually be realised. So if it will not be our work it will be that of others. One day humans shall have wings and be free! This article is meant to lay open our lessons learnt so the journey of Fluglicht can be picked up and continued.
History and General Lessons
Back in 2016 when I, Peter, first had the idea of how to fly like a bird, I would have never expected it to get this far. I was still studying and had worked on a project to build a flying bicycle. The idea came up, after calculating wing areas for this project and I wondered: "why do we actually not fly like a bird? Is there a technical obstacle that can not yet be solved or anything like that?" Being a fledging aerospace engineer, I put myself to work and started to calculate. But in these rudimentary numbers I couldn't see any hindrance:
- the power supply was there (small turboshaft engines),
- the material for the wing structure was there (carbon fibre reinforced plastics) and capable of taking the loads,
- the actuators to make the wings flap were there (small hydraulic cylinders and/or electric motors)
- the sensors and fast control systems were there (small computers being the keystone)
- the accelerations and aerodynamics weren't too crazy.
So finishing my studies in 2017, I decided to try and make it happen! First, I made a CAD model of the concept and applied for a patent. I also had some start-up experience and knew what student projects like the car racing teams could acheive. So I jumped into the unknown and moved to Dresden in 2018. Why Dresden you may ask? Well, "intelligence" showed it had low cost of living, a lot of free space, a technical university with presumably eager students, and local actors looking for and supporting young founders.
Here is the first lesson to learn! What is ACTUALLY crucial to get an audacious project like Fluglicht of the ground is the following:
- being in a place, where people gather that are ambitious, open minded, and willing to help each other with connections and real effort
- being in an environment where money and support flows easily towards those people taking risks to convert big chances.
Dresden was not that place. The overwhelming majority of people here (including students) were risk averse, have a very modest (if not "depressed") perspective on life and were highly suspicious of people with big dreams. As a consequence, I had to face general disinterest and even active resistance from many sides. Limited support came from the start-up facilitators who were amazed by the idea and spirit, but couldn't give out any funds due to risk aversion of the national fund-owners.
Extreme risk aversion is a fundamental issue, deeply ingrained in Germany, and is slowly dismantling the economy of this place. But that's a different discussion. Suffice to say, even 35 years after the fall of the Berlin wall, East Germany is still fighting with depression (and I don't mean the economic one). It is an interesting question how one could "heal" whole societies from something like that. Or more general also hatred, cowardice, distrust, greed, egoism, powerabuse, and corruption. Part of Fluglicht was the attempt to bring hope and excitement for a positive future back into the hearts of people. Maybe that was at least a partial success, as many people we talked to were amazed by the idea (but unable to help).
In hindsight I probably should just have packed my bags and gone to the USA. MIT, Caltech, Stanford - one of these. Students at these universities regularly surprise the world with novelties. And when we visited in May 2024, people told us that before Covid-19, the funds for crazy ideas in Silicon Valley were flowing in copious amounts. Oh, well...
But back to the story. I managed to gather a small student team with people coming and going. The inital plan was to build the full scale wings as a student team within 2 years relying on sponsoring. In Stuttgart, I witnessed the power of what student teams can accomplish first hand. It didn't go that way. Due to the small size of the team and lack of sponsors, this plan was scrapped in exchange for building what is now the Exoskid. There is another lesson right there: the team is key and you have to have people on the team that actually WANT to do the tasks at hand. If for example nobody is keen to do financials and get sponsors, it's unlikely to happen. It's the difference between being capable and having the appetite to do something. After about a year, the team stabilised with a few very talented and motivated engineering students at the prototyping. I also got better in project management and leadership. At one point even a sales person joined but there is another lesson there: only take up people into the team that are team players and fit with the rest of the team. In the end it was a complete mess when I ignored my gut feeling. It worked for some time, even though none of the goals were reached. But at one point it just got ugly and I had to throw him out.
And then, the world turned outside-in and Covid-19 happened. At that time, I had taken up a "part time" job as research associate (PhD student) and the lock-down actually came as a relief. Having two factually-fulltime jobs for a year brought me into extreme overwork. The day just never felt finished, no matter how much effort I put in. This is another lesson: leading something like Fluglicht is no part time job. You've got to burn bright to shine through the haze. This is really tough. Keeping morale up when everything feels like walking through a swamp takes a lot of strength and grit. "Optimism is true moral courage" as Shackelton would have said. So, caring for your own mental health is crucial not to wear out.
Despite the general weirdness of a pandemic, the team stuck together and we had a few sessions in the lab with extreme care. Martin started to design and build the airplane for the exoskid. Leon iterated the exoskeleton design, which we then built and fully equipped with sensors and the Arduino. In 2019 we already had an exoskeleton arm that could move our original hydraulic wing model. The system later called Exoskid now should use servo motors on the airplane. There are two lessons right there. For one: Teams work a lot better, if everyone mostly works on things they actually enjoy and are interested in. Secondly: the amount of work needs to fit to the available hands. Not the other way around! That was hard to realise and accept when I knew what could have been acheived with a larger group. But once we had the right kind of goal that was acheivable and distributed work the right way, things started to happen a lot faster! SMART Goals help. Over the years, I had also built up some digital infrastructure like a landingpage, cloud, Kanban board and communication system. That also helped.
At the end of 2021 the exoskeleton was almost finished, except for the ankles. The wired connection between Exoskeleton and Skid was working. We could flap the wings and produce some wind in the lab. In 2022 the ankle joint system was designed and four-way-ultimate-pong developed (Pong with four bars, controlled entirely with the Exoskeleton). A lot of microcontroller work was done. We struggled to get a radio channel for the exoskeleton data running. In the end we hacked the Flysky's radio link and fed the signal into the Flysky via the trainer port. Probably wouldn't have happened without our Linux and Embedded guru Chris! But on the whole we wrangled the system until we completed the full system integration test in January 2024.
It was an awesome feeling, when we stepped outside for our fist flight in Febuary! You can read that story here. The lesson of this experience is: have good communication prepared! Like having a checklist to prevent misunderstandings and errors with the complex system. And have clear communication prepared for when something goes wrong. The crash might not have happened (like this) if we have had that.
We didn't let ourselves be stopped, though. Lean work means "build, measure, learn", doesn't it? So we rebuilt the airplane with improvements and went out for the second run in April. This time, we got much longer flight time but were again cut short on exoskeleton flight time by material failure. The only lesson here is: avoid shitty FDM filament! Or you might find yourself wading through a field of flowering rapeseed for 2 hours trying to find the rapid unscheduled disassembly of your project...
In any case, we collected enough data to take the next step: proper funding. I had worked for a long time on the business model and pitch for Fluglicht. With Leon up as a co-founder, we plunged into an airplane and slapped down in Palo Alto. The Start-Up House catapulted us then back and fourth through the Valley, talking to awesome people like Jim Duchovny (Alef) and Yashar Moradi (MOD), gaining valuable connections (also to Germany), pitching at Stanford Startup Society and to Investors in the Hacker Dojo and at GoGlobal.
It was a wild two weeks in the Bay Area and in LA! The main lesson here was that going out there, getting the idea known, and connecting to people is everything. On these "mixer" events found on Meetup, Eventbrite, and Luma, me actually found the real chances (search for e.g. "mix & pitch"). This is where the power of the Valley unfolds, because people there are willing to help you by making connections. Also they give great feedback, if asked the right way (#The Mom Test). Almost everything works via this networking, as it is futile to just go to Sand Hill Road and walz into Sequoia Capital (even though that was scay and fun at the same time...)
The next lesson we learnt was: preparation is everything. Having your introduction and (elevator-)pitches of all length ready will not waste valuable potential (1, 2, 3, 5, 7, 10 min pitches - with and without slides). Also, having a clear goal which investors you want to get a warm intro to and who you need to talk to for that, is critical! Many things come with the flow, when you meet a random person at an event that knows just the right people. But time is limited!
In the end we had to realise that two weeks are just not enough when starting from scratch. We already had gotten quite far, but did not have the luck to make the winning connection. The main lesson here is: stay longer in California! It's bloody expensive, but the only place on earth where the real crazy shit has a chance, and where EVERYONE helps the others to achieve. And another important lesson is (again): get the right person for the job. We probably didn't manage to "sell" the wings good enough to gain traction with the investors. (NOTE: more on the learnings from the valley in the business lessons article!)
Back in Germany, I kept on working on our gained traction and had the pleasure to meet Daniel Wiegand of Lilium (thanks a lot Yashar!). The conversation was very interesting and inspiring but, bottom line, it didn't transpire anything. And to be honest, the Valley trip was my last hope on getting the funds. Nothing in Germany had borne fruit in the last 6 years. And the prospect to go throught the tedium of getting warm intros to all the investors on our list wasn't appealing. We searched for a business co-founder, to no avail. I pushed on to the end of 2024, gaining at least a pitch to an aerospace affine angel investor.
But when this didn't work out, something broke inside. I had to admit to myself that I didn't have the strength to push on, even though a lot of leads were still untouched. So I called Leon and told him, I wanted to stop the project. Not an easy decision, when something has been the pride and joy of ones life for that many years! But in hindsight I can say, it was a good and necessary decision. Admiting defeat is painful and it took me a year to be able to sit down and write this up. But in the end, the death of one project opens up space for something new!
If you are interested in the lessons of technology development and the business development, I wrote two more lengthy articles about that. You can find the links below!
Technical Lessons
The deep dive into the technology can be found here.
Business Lessons
Our lessons learnt for the business part can be found here
Resumee
So after 7 years of struggle, can I answer the question "is human birdflight possible?" What is the biggest lesson of them all?
Yes, human birdflight with a flying exoskeleton can work! From a technical side, there are no fundamental roadblocks. It won't be easy and to get the performance up will take time. But it can be done. The bigger challenge is that it's ludicrously hard to get the funds together to pay the engineers and materials. And the reason is that it's a high risk, uncertain reward endeavour. Few people will be willing to put money in it. THAT is the real reason, why it hasn't been built yet. So the crucial task is, getting it built once and then prove how much love people really harbor for flying like a bird.
Looking back, there is also the question, if it was worth it. Seven years of struggle, many weeks of work to compile all the information here... will it be all for nothing?
Indeed, we didn't make it in the end. But we leant A LOT in that time. It was daunting, straining, uncomfortable, and even painful at times. But also exciting, stimulating, fun and even exhiliarating! I grew alot as a person, especially from the challenging parts. And with the most important information gathered here, I'm hope strongly, all the pain was not in vain. Since aeons men have turned their heads skywards, hearts full of Fluglicht. So if it will not be our work, it will be that of others. I'm certain: this dream will never perish! And one day, humans shall have wings, and they shall fly!
