Complete the sentences according to the sense. Match the beginning and the end of the sentence.

1) The latest high-thrust blades allow the main rotor…

2) The active twist rotor has shown substantial reduction in noise…

3) Manufactures are testing main rotor blades with active servo flaps…

4) Smart, or active, structures also promise…

5) As forward speed increases, airflow over the advancing blade gets faster…

6) Windtunnel testing indicates the reverse-velocity rotor is capable…

7. the tiltrotor has speed and range advantages…

… to reduce internal noise as well as vibration, …but the configuration present

challenges, … and vibration in NASA windtunnel testing, …while that over the

retracting blade gets slower, … to be slowed in the cruise, …driven by piezo-

electric actuators, …of cruise speeds exceeding 300 kt.

Speaking

Make up false statements and let your group mates correct them.

Example:

S1: Compared with equivalent fixed-wing aircraft, helicopters are still much cheaper to buy and to operate.

S2: False. Compared with equivalent fixed-wing aircraft, helicopters are still more expensive to buy and costly to operate.

2. You are a designer of a helicopter and are going to make a report at the conference. Speak on the following topics:

- advantages of helicopters

- disadvantages of helicopters;

- helicopter improvement;

- future tiltrotors

- a problem of noise reduction

3. Make a summary of the text “Vertical Horizons”.

UNIT 5

Spacecraft Propulsion

Preparing to Read

Brainstorm all possible terms related to the topic.

Work in pairs, share the words and give your prediction about the content of the text.