Understanding Aircraft Systems and Instruments

What is the primary function of a hydraulic system in an aircraft?

• To provide electrical power to the aircraft

• To operate systems like the undercarriage, flaps, and brakes

• To measure airspeed

• To control cabin pressure

Answer explanation

The primary function of a hydraulic system in an aircraft is to operate systems like the undercarriage, flaps, and brakes, providing the necessary force to control these critical components effectively.

How are the wheel brakes on an aircraft typically operated?

• By hand levers

• By toe pedals on top of the rudder pedals

• By a central brake pedal

• By voice command

Answer explanation

Aircraft wheel brakes are typically operated by toe pedals located on top of the rudder pedals, allowing pilots to control braking while maintaining foot placement for rudder control.

What does the altimeter measure?

• The speed of the aircraft over the ground

• The height of the aircraft above a pre-selected surface level

• The temperature outside the aircraft

• The fuel level in the aircraft

Answer explanation

The altimeter measures the height of the aircraft above a pre-selected surface level, typically sea level. It does not measure speed, temperature, or fuel level.

What is the main purpose of the pitot tube on an aircraft?

• To measure the altitude of the aircraft

• To measure the flow velocity of the air past the aircraft

• To provide oxygen to the cabin

• To control the aircraft's navigation system

Answer explanation

The main purpose of the pitot tube is to measure the flow velocity of the air past the aircraft. This measurement is crucial for determining airspeed, which is essential for safe flight operations.

What is the function of the Vertical Speed Indicator (VSI)?

• To indicate the rate of fuel consumption

• To indicate the rate at which an aircraft is climbing or descending

• To measure the aircraft's speed over the ground

• To display the aircraft's heading

Answer explanation

The Vertical Speed Indicator (VSI) measures the rate of climb or descent of an aircraft, providing crucial information for pilots to maintain desired altitude changes during flight.

What happens when the left toe brake pedal is pressed?

• The right main wheel slows down

• The left main wheel slows down

• Both main wheels slow down

• The aircraft accelerates

Answer explanation

Pressing the left toe brake pedal applies braking force to the left main wheel, causing it to slow down. This action does not affect the right main wheel, so the correct answer is that the left main wheel slows down.

What is the relationship between dynamic pressure and static pressure in a pitot tube?

• Dynamic pressure is less than static pressure

• Dynamic pressure is equal to static pressure

• Dynamic pressure is greater than static pressure

• Dynamic pressure has no relation to static pressure

Answer explanation

In a pitot tube, dynamic pressure, which is caused by fluid motion, is measured as the difference between total pressure and static pressure. Therefore, dynamic pressure is greater than static pressure, making the correct choice: dynamic pressure is greater than static pressure.

How does the airspeed indicator (ASI) measure speed?

• By measuring the speed over the ground

• By measuring the speed through the air

• By measuring the speed of the wind

• By measuring the speed of the engine

Answer explanation

The airspeed indicator (ASI) measures speed through the air by comparing the dynamic pressure of the air entering the pitot tube to the static pressure. This provides the aircraft's speed relative to the surrounding air, not the ground.

What is the purpose of the heated pitot head?

• To increase the speed of the aircraft

• To prevent icing of the pitot tube

• To measure the temperature of the air

• To provide additional lift

Answer explanation

The heated pitot head is designed to prevent icing of the pitot tube, which is crucial for accurate airspeed measurements. Icing can block the tube, leading to erroneous readings and potential safety issues.

What does the pressure altimeter resemble?

• A thermometer

• An aneroid barometer

• A compass

• A speedometer

Answer explanation

A pressure altimeter measures altitude by comparing atmospheric pressure, similar to an aneroid barometer, which also uses pressure changes to indicate altitude. Thus, it resembles an aneroid barometer.