PitotStatic System l Pitot Tube measures dynamic and

Pitot/Static System l Pitot Tube – measures dynamic and static pressures and is positioned to be clear of the slipstream and facing the line of flight. THE AIRSPEED INDICATOR IS THE ONLY INSTRUMENT CONNECTED TO THE PITOT PRESSURE SOURCE. Regional Gliding School

Pitot/Static System l Static Tube – measures static pressure. The tube is vented to allow air pressure inside the instrument case to equalize with the outside air pressure. The vents are located on opposite sides so as to not be affected by turbulence. ASI, ALTIMETER, VSI USE STATIC PRESSURE. Regional Gliding School

Pitot/Static System Regional Gliding School

Altimeter l Measures the pressure in the atmosphere, which is the weight of the air above you at any given altitude. This weight will change as the aircraft climbs or descends causing the altimeter to register a change. Regional Gliding School

Altimeter l Made up of a stack of aneroid capsules each set at standard sea level. As the altitude changes these capsules expand contract moving gears and thus the hands on the altimeter change. Regional Gliding School

Altimeter Errors l Pressure: – the atmospheric pressure changes when flying from place to place. If not corrected the altimeter will be inaccurate. l Temperature: – the altimeter is constructed to work on the values of the ICAO standard atmosphere (15 C), the temp is not always at this value. Regional Gliding School

Altimeter Errors l Mountain Effect: – when flying near mountains, winds can be gusty and cause a drop in local pressure. Consequently, the altimeter will not give an accurate altitude indication. Regional Gliding School

Airspeed Indicator l Tells the pilot how fast they are traveling through the air and not over the ground and is measured in knots and miles per hour. Indicates the difference between pressures in the pitot and static tubes. Regional Gliding School

Airspeed Indicator l The reading on the airspeed indicator is referred to as the Indicated Airspeed (IAS). True airspeed (TAS) is the calibrated airspeed corrected for airspeed indicator error due to density and temperature. Regional Gliding School

Airspeed Indicator l The instrument is made up of an aneroid capsule which measures the pitot pressure. The interior of the case is sealed and the static pressure is measured there. The changes in dynamic pressure (pitot) cause the aneroid capsule to expand contract and this is registered and connected to a linkage that moves the hand on the ASI. Regional Gliding School

Calibrated Airspeed l Is indicated airspeed corrected for instrument errors and installation errors in the pitot static system Regional Gliding School

Equivalent Airspeed l Calibrated airspeed corrected for compressibility factor. Regional Gliding School

Airspeed Markings Red Velocity never exceed (Vne) Yellow Caution (Vno) Green Normal (Vsl) White Flaps (Vfe) Regional Gliding School

Airspeed Errors l Density: – atmospheric density varies and as a result this will change the accuracy of the ASI. l Position: – Eddies that form as air passes over the wing are responsible for error. l Lag: – the slowness of the working parts are responsible for this error. Regional Gliding School

Airspeed Errors l Icing: – ice formation blocking either the pitot or static tube could give inaccurate readings. l Water: – water could block the tubes causing inaccurate readings. Regional Gliding School

NOTE: You must use the buttons in the Confirmation Stage Regional Gliding School

Theory of Flight Aircraft Instruments Let's try a few review questions on Theory of Flight: Question #1 - Regional Gliding School Which instrument is used to indicate height above sea level? A Altimeter B Airspeed indicator C Pitot indicator D Static indicator

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . .

Flying Scholarship Program That answer is correct. Let's move on. . .

Theory of Flight Aircraft Instruments Let's try a few review questions on Theory of Flight: Question #2 - Regional Gliding School What is indicated airspeed corrected for instrument errors and installation errors in the pitot static system. A True airspeed B Indicated airspeed C Equivalent airspeed D Calibrated airspeed

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . .

Flying Scholarship Program That answer is correct. Let's move on. . .

Vertical Speed Indicator l Indicates the rate of climb and descent and is measured in feet per minute. Regional Gliding School

Vertical Speed Indicator l l Measures the change in pressure between the capsule (atmospheric pressure) and the case of the instrument. The capsule will expand contract which is then transmitted by linkage to the dial of the instrument. The instrument tends to lag and will only show an accurate after 6 -9 seconds. Regional Gliding School

Variometer l A very sensitive rate of climb indicator that is used to find thermals. Works on the same principle as the altimeter: the higher the altitude the less the static pressure. Regional Gliding School

Magnetic Compass l Consists of two north seeking magnets which are attached to a float which is also attached to a compass card. This complete magnet system is mounted on a pivot and is free to rotate. The whole assembly is mounted within the compass bowl which is filled with alcohol to reduce the weight of the compass card and the magnets. The lubber line indicates the direction the aircraft is heading and is in line with or parallel to the longitudinal axis of the aircraft. Regional Gliding School

Gyroscope l It is a rotor, or spinning wheel, rotating at high speed in a universal mounting, called a gimbal, so its axle can be pointed in any direction. l Gyroscopic Inertia: – the tendency of a rotating body to maintain its plane of motion. Regional Gliding School

Gyroscope l Precession: – the tendency of a rotating body, when a force is applied perpendicular to its plane of rotation, to turn in the direction of its rotation 90 to its axis and take up a new plane of rotation parallel to the force applied. Regional Gliding School

Gyroscope Regional Gliding School

Gyro Instruments The Heading Indicator l The heading indicator or directional gyro is an instrument designed to indicated the heading of the airplane and because it is steady and accurate, to enable the pilot to steer that heading with the least effort. Regional Gliding School

Gyro Instruments The Artificial Horizon l The artificial horizon or attitude indicator provides the pilot with an artificial horizon as a means of reference when the natural horizon cannot be seen because of cloud, fog, rain or other obstructions to visibility. It shows the pilot the relationship between the wings and nose of the airplane and the horizon at the earth. Regional Gliding School

Gyro Instruments Turn and Slip Indicator l Needle indicates the direction and rate of turn. l Ball indicates slipping or skidding l If the ball is opposite to the needle in a turn you are skidding. With the ball and needle on the same side the turn is slipping. Regional Gliding School

Gyro Instruments Turn and Slip Indicator Straight and Level Coordinated left Turn Skidding Left Turn Slipping Left Turn Regional Gliding School

NOTE: You must use the buttons in the Confirmation Stage Regional Gliding School

Theory of Flight Aircraft Instruments Let's try a few review questions on Theory of Flight: Question #3 - Regional Gliding School A rotor, or spinning wheel, rotating at high speed in a universal mounting, called a gimbal, so its axle can be pointed in any direction is known as. A Variometer B Magnetic compass C Gyroscope D Vertical speed indicator

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . .

Flying Scholarship Program That answer is correct. Let's move on. . .

Theory of Flight Aircraft instruments Let's try a few review questions on Theory of Flight: Question #4 - Regional Gliding School What instruments work on a gyroscope? A Variometer B Artificial Horizon C Magnetic compass D Vertical speed indicator

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . .

Flying Scholarship Program That answer is correct. Let's move on. . .

Theory of Flight Aircraft Instruments Congratulations!! You have now completed the Aircraft Instruments lesson and the Theory of Flight Module. Of course, this lesson and module is always available to you for future reference if required. You are now ready to move along to the next module you have not completed. You can advance to the Self Test Module if you feel ready to challenge the final exam. Good Luck! Regional Gliding School