Aviation · Folio 01
Chronos-747: the jumbo jet that runs on springs
The math is consistent. The physics says no. Here's what I learned trying.
Carl-Oscar Bromander
Built using AI assistance · Updated 22 September 2026
The story
It started as a fun "what if": what if a jumbo jet could fly on stored spring energy instead of jet fuel, charged in nine minutes like a giant wind-up toy?
I'm not an engineer. I'm a founder who likes big ideas, so I explored this one together with an AI assistant. I brought the ideas; the AI did the math, checked the physics, and told me honestly when something didn't work.
And a lot didn't work. My springs turned out to be about 26 times too heavy, and vertical takeoff would drain them in minutes. But the safety ideas held up, and every failure pointed somewhere new.
Specification
Concept specs
- Weight
- 590 t: 110 t airframe + 480 t springs, plus payload
- Energy storage
- 1,000 sealed nanotube spring modules, 89 MWh
- Charging
- 600 MW, 200 pins at 3 MW each, 9 minutes
- Estimated range
- Approx. 1,000 km
Want what works, what fails, the revision history and the discussion?
Open the complete editorial analysis for this concept.
Next concept
Blunda: glasses that close their eyes
Camera glasses with a hardware permission switch and a mechanical shutter that shows exactly when the camera can see.
From the makers of
Ideas here. Everyday tools elsewhere.
Gentle reminder companion
Vividly
A little help getting started.
For ADHD and neurodivergent minds: gentle reminders and personal motivation for the things that matter to you.
Meet Vividly
Digital wellbeing
Shinery
More of your own thinking.
Understand your AI habits, reflect on your usage, and take steps towards greater cognitive independence.
Explore Shinery
Bromander Studios & Labs
Labs
Less guesswork. Better tools.
Free, browser-based tools for AI engineers: check your hardware, estimate costs, and plan inference. No signup needed.
Explore Labs