Fill in the diagram with missing information from the text.
The text has 9 paragraphs. Which paragraph mentions a) different landing devices; b) vehicle flying due to up and down air streams; c) vehicle able to hover in the air?
Read the text again and decide if these statements are true or false. Correct the false ones.
1. Modern heavier-than-air aircraft are classified into two classes according to their flying principle.
2. Airplanes fly due to up and down air stream.
3. Gliders are equipped with airscrew and power plant.
4. Airplanes can be fitted with floats to take off and land on water.
5. In helicopters lifting force is produced by the wing itself.
6. The helicopters can take off and land vertically.
7. The autogiros and ballistic rockets fly on the same principles.
8. Ballistic rockets do not produce lifting force by means of a wing.
Ask your partner ten questions about types of aircraft.