Pioneers of flight

4. strong cloth made from the fibres of the flax plant
5. a bar or handle that moves around a fixed point, so that one end of it can be pushed or pulled in order to control the operation of a machine
6. a person who is one of the first people to do something
7. a strong metal that is a mixture of iron and carbon, used for making things that need a strong structure, especially vehicles and buildings
11. not allowing water to go through
14. these stems used as a material for making wicker furniture, or furniture made from them
15. height above sea level
17. the fact of someone or something not succeeding
19. to go or come down
20. a bag or similar container, especially one of a pair that hang on either side of a bicycle, motorcycle, or animal such as a horse or donkey
21. to control the direction of a vehicle

1. curving in
2. the ability to understand an event or situation only after it has happened
3. the part of a steam engine where water is heated to provide power
8. to copy something achieved by someone else and try to do it as well as they have
9. a supporting structure around which something can be built
10. to fall down suddenly because of pressure or having no strength or support
12. delicate, soft type of cloth made from a thread produced by silkworms, or the thread itself
13. a long, thin pole made of wood or metal
16. a test, usually over a limited period of time, to discover how effective or suitable something or someone is
18. a flat piece of wood or metal at the back of a boat or aircraft, moved from side to side in order to control the direction of travel