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Text B

Aircraft instruments (part II)

Instruments Concerned with Propulsion Information

Speed. Engine speeds are measured and shown on rpm indicators which measure the revolutions per minute of the main rotor in each engine.

Temperature. The temperature of each engine on an aircraft is measured and shown on a temperature indicator.

Pressure. A manifold pressure gauge is an instrument for measuring the absolute pressure in the induction system (a branched pipe for distributing air or a mixture to a number of cylinders) at a point standardized for each engine.

Instruments Concerned with Information about Fuel

Fuel Content. Fuel tank contents indicators show how much fuel the aircraft has left at any moment of time.

Fuel Flow. The fuel consumption of each engine is measured by fuel flowmeters calibrated in kilos per minute.

Instruments Concerned with Information about

Conditions on the Outside of the Airframe

Temperature. The outside air temperature (OAT) gauge gives the pilot general information about the temperature of the air immediately surrounding the airframe.

Pressure. It is important to know the pressure inside the passenger cabin because it must be neither too high nor too low for human comfort. It is also important to know the difference between the air pressure outside the cabin and the air pressure inside it because it represents a force exerted in normal circumstances in an outwards direction.

Instruments Concerned with Information about the Aircraft's

Electrical System

Voltage. Direct current and alternating current voltages are measured and shown by AC and DC voltmeters. Where information is required only periodically from a number of points it is usual to have only one voltmeter with a device for selecting each point of measurement as required.

Current. The instrument that measures an electric current in amperes is called an ammeter.

We may summarize the nature of information presented by aicraft instruments as

follows:

(a) it may be continuous presentation, as in the case of a gyrohorizon.

(b) it may be on-tap presentation, as in the case of moving a switch for a

particular reading on a voltmeter.

(c) it is always concerned with situations that are expected to change within

certain limits, for example temperature.

(d) most is presented visually.

Active Vocabulary to Text b

propulsion	- двигатель
revolutions per minute	- обороты в минуту
gauge	- измерительный приброр
fuel flow	- расход топлива
airframe	- корпус, каркас
consumption	- потребление
current	- ток
to exert	- влиять
to moove a switch	- переключять
to concern with	- описывать
neither … nor...	- ни... ни...

Questions to Text b

1. What are the instruments concerned with propulsion information?

2. What's the difference between fuel content and fuel flow?

3. What are the instruments concerned with information about conditions on the outside of the airframe?

4. Why do we need the instruments concerned with information about conditions on the outside of the airframe?

5. Where is the information required only periodically?

6. What is an ammeter?

7. To how many points may we summarize the nature of information presented by aicraft instruments?

8. May it be continuous presentation or on-tap presentation ?

9. Are there instruments concerned with situations that are expected to change ?

10. What is presented visually?