Hi! to craft the engine(blueprint) parts you need :
Aluminum resources
Which can be found in packages located at all the rebel bases.
Once looted, you can find it under "Parts" category in your inventory.
You can read more at (blog): https://www.ashore-game.com/single-post/2017/05/26/Update-48-Survival-Ending-Par...
Or by pressing 'F2' in the game to access the game guide > escape (it explains step by step how to escape).
Goodluck!
Let me know if you need anything, cheers!