X Study the following schemes , remember them and speak on the topics.

 

 

 

UNIT 13AIRCRAFT POWER DISTRIBUTION

AIM OF THE UNIT:- to describeaircraft power distribution

TASKS

1 Do your best to answer the brainstorming questions. 2 Read the text for general understanding.

3 Make up questions to the text. 4 Find the sentences with the new words in the text. Give the Kazakh or Russian

equivalents of the words.

5 Write sentences with the new vocabulary. 6 Do the given exercisesfor better remembering the topic.7 Speak on the topic. Given schemes and questions will help you to remember and

understand the topic.

8 Find more information about the topic. Do some research, create slideshow or a

project work and present them.

Brainstorming questions

1 What types of buses do you know?

2 How manytypes of power transfer contactors do you know?

Each type of aircraft has a group of buses identified bythe priority of the equipment it powers. For example, a flight-essential bus may power emergency lighting, critical flight and engine instruments, and/or an emergency radio. Less important critical equipment receives power from an essential bus. Normal systems used to complete the assigned mission or provide crew comfort are on the main bus. The input to a bus may be either dc or ac. The output from the bus has a protective device such as a circuit breaker, fuse, or current limiter.

There are basically two types of power transfer contactors: single coil and double coil. A single coil contactor consists of auxiliary contacts and two sets of three main contacts with a paralleled common output. The auxiliary contacts normally control identification lights on the power control panel. The two sets of three main contacts are arranged so that only one set of contacts can be closed at a time. A double coil relay is a two-section mechanically interlocking device having two energizing coils.