My world is far away exoplanet with water and some oxygene, but without life or plants, which means without coal and organic materials inside.
High tech people from Earth come there and made some quick (and succesfull) terraforming but after that, and after building the cities, vast majority of them cannot survive the planet conditions and people starts to die slowly due to health complications. Planet is classified as dangerous and deleted from future missions from Earth. Those few people who survives starts wars for goods and tech era is finished in three or four generations after all machines will run out of energy and get destroyed.
After hundreds of medieval years they just adapt for the planet, and start to rise again. They start new industrial revolution (with some historic books written by wise people from first era, so they have handwritten historic step-by-step guide to some crutial inventions, which speeds things up). They will use hydropower, got lots of mining, got steam engines, railways, boats, cars, ethanol engines instead of classic fuel. People gets to 1850 - 1900.
But what about planes in such era?
1) Materials: can be such a strong conventional engine built without steel? Can it be just an iron engine, or lithium / aluminium or whatever unorganic metal? Does any material have such good behavior like steel, but not based on organic materials?
2) Fuel: can it runs on etanol, whale oil or some bio fuel instead of classic fuel? Or it should only be sort of eletric / solar engine and thus produced quite later?
*note: this is max reality world. The only made-up thing should be the apocalypse. Everything other should be real, like we were really there and tryin to survive with everything we have.
Really thanks for answers.