Flight - Instruments of Flight

start... Outline • • • • • • • • Introduction Altimeter Airspeed indicator Vertical speed indicator Heading indicator Attitude indicator Turn coordinator Summary Introduction • History – the very first aircraft had little to no flight instruments – all weather flying was risky – navigation depended on pilot’s ability to use landmarks Introduction • The common flight instruments – altimeter – airspeed indicator – vertical speed indicator – heading indicator – attitude indicator (“artificial horizon”) – turn coordinator Altimeter • Defining the altimeter – barometric gauge – determines how high the aircraft is from sea level (altitude) • How it works – measures air pressure that enter through static ports Altimeter – air pressure increases and decreases as the aircraft descends and climbs – a wafer inside the instrument case expands and contracts with the change in a pressure • How to read the altimeter – looks like a clock with a long and short hand – measured in feet Altimeter 9 8 0 ALTITUDE This shows aircraft at 5,250ft 1 2 7 Thousands of feet 3 6 4 5 Hundreds of feet Hatched warning flag in view mean airplanes is below 10,000ft. Airspeed Indicator • Defining the airspeed indicator – differential pressure gauge – tells the pilot how fast the plane is going • How it works – measures air pressure entering from two inlets • “base” air pressure • “ram air” air pressure – the difference between the two air pressures is sent to the gauge to indicate airspeed Airspeed Indicator • How to the airspeed indicator – displayed digital and/or analog – measured in knots Analog 160 40 60 80 100 AIRSPEED KNOTS Digital 140 130 KTS 120 Vertical Speed Indicator • Defining the vertical speed indicator – pressure gauge – used to maintain proper rate of climb and rate of descend • How it works – like the altimeter, but measures rate of change • uses an expandable wafer that expands and contracts with the change in air pressure – calibrated to show a level reading when case air pressure equals air pressure in wafer Vertical Speed Indicator • How to read the VSI – measured in feet per minute Numbers above “0” indicate a positive rate of climb “0” is the center markaircraft is level 10 5 15 VERTICAL SPEED 0 5 20 15 10 Numbers below “0” indicate a negative rate of climb Heading Indicator • Defining the heading indicator – also called directional gyro – provides accurate directional information in relation to earth’s magnetic north • How it works – uses an internal gyroscope that rotates a compass card on the instrument face – When the aircraft turns, the needle indicates which direction it is heading Heading Indicator • How to read the heading indicator – measured in degrees (0-north, 90-west, 180south, and 270-east This aircraft is heading north A number is displayed every 30 degrees Reads in five degree increments Represents the aircraft’s profile if looking down Attitude Indicator • Defining the attitude indicator – also called the “artificial horizon” – displays both “pitch” and “bank” simultaneously • pitch-aircraft movement on its lateral axis • bank- aircraft movement on its longitudinal axis Attitude Indicator • How the attitude indicator works – uses a gyroscope mounted inside the instrument case – the gyro rotates in the horizontal plane in relation to earth’s horizon – this happens as the aircraft banks, climbs and descends – this relation is show on the instrument face using an “artificial horizon” Attitude Indicator • How to read the attitude indicator – the center of the gauge is the artificial horizon Blue is sky Hatch marks indicate degree of bank Simulates aircraft profile if looking from the tail Center hatch marks indicate degree of pitch Brown is ground Turn Coordinator • Defining the turn coordinator – uses a gyroscope – shows aircraft rate of turn • how fast it is changing speed – shows quality of turn • if the turn is coordinated – serves as a back up to the attitude indicator Turn Coordinator • How the turn coordinator works – a gyro is mounted at a 30 degree angle inside instrument case – as the aircraft turns , applied forces cause the gyro to spin and rotate – as this happens, the small plane on the instrument face indicates bank Turn coordinator • How to read the turn coordinator – measured in degrees per minute If wings touch top hatch mark the aircraft is not turning A wing touching the “L” or the “R” indicates a standard rate of turn Turn coordinator • The slip/skid on the turn coordinator – usually at the bottom of the instrument Keeping the ball in the center of two line indicates a coordinated turn Summary • Flight instruments all together have made – navigation easier – communication easier – fault detection and warning indication possible – takeoffs and landings easier – and most important flying safer The End