2. 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

1. 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

1. Brainstorm all possible terms related to the topic.

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

3. Read the statements and agree or disagree with them and explain your viewpoint.

1. When in space, the purpose of a propulsion system is to change the velocity of a spacecraft.

2. When launching a spacecraft from the Earth, a power plant must overcome the Earth's gravitational pull.

3. Any rocket engine is air-breathing engine.

4. The rocket engine must provide impulse to overcome Earth gravitation.

5. Rocket engines provide 100% efficiency.

Reading

1. Scan the text and try to explain what underlined terms mean according to the content of the text.

2. Read the text and match the English words with their Russian counterparts.

1. delta-v a. рабочее тело

2. reaction mass b. межзвёздный полёт

3. resistojet с. солнечный парус

4. ion thrusters d. ионный ракетный двигатель

5. tangential e. омический ракетный двигатель

6. aerobraking f. аэродинамическое торможение

7. solar sail j. касательный, направленный по касательной

8. interstellar travel h. характеристическая скорость