5. FLIGHT INSTRUMENTS

from Come Fly With Me – Exploring Science through aviation and aerospace concepts.

SUBJECT: Science
GRADE: 7,8,9
GROUP SIZE: Individual or Small group
TIME: 2-45 Minute periods
TYPE OF ACTIVITY: Simulation Student Investigation
TEACHING STRATEGY: Expository Guided Discovery
CONCEPTS: Flight Instruments Visual Flight Rules Instrument Flight Rules
SKILLS: Construction, Observation Interpreting Data
Objectives: To introduce the basic flight instruments contained in an airplane; to manipulate models of flight instruments and learn how to read them.

Materials: Activity sheets; copies of the demonstration sheets for each student or group of students; tag board; scissors; rubber cement; brass fasteners.
Teacher Background Information:

This lesson deals with the instruments used in beginning flight training. At first glance, the instruments look difficult to use but, in fact, with a minimum of practice they are quite simple. The lesson, though it takes time to prepare, is well worth the effort as a model for reading data from instruments and as an an example of the importance of precision when reading instruments. Early navigation in planes meant following landmarks on the ground by day and by night, following a trail of bonfires set by farmers. Later, light beacons spaced a few miles apart, were the state-of-the-art for night flying in good weather. Sometimes pilots were forced to land in a farmer’s field along the way if weather turned bad and the farmer would find passengers from the airline as uninvited guests for the night. By the late 1920’s and early ’30’s, a system of emergency airports had also been established along cross continent routes. Modern systems of navigation use radio beacons which are read by instruments in the plane and point the way along a flight path.

The AIRSPEED INDICATOR is read like the speedometer of a car and tells the pilot how fast the plane is moving through the air. The speed of a head wind would be subtracted from the airspeed reading to arrive at the speed over the ground (ground speed). Tail winds should be added to the airspeed. Colored arcs on each plane’s airspeed indicator tell the pilot what the safe operating speeds are and when flaps or landing gear can be extended.

The ALTIMETER tells the pilot how high above sea level the plane is which can be interpreted as how high above the ground the plane is by looking at a map and finding the altitude of the ground below. There are 3 hands on the altimeter. The shortest indicates 10,000 feet, the middle length indicates 1,000 feet and the longest hand indicates 100 foot increments.

The TURN AND SLIP INDICATOR tells the pilot when he or she is making a coordinated turn. The needle indicates how the ailerons are being used and the ball indicates whether the rudder is being used correctly to balance the turn. The ball stays in the center when a turn is balanced, otherwise the ball “slips” to the side.

The ARTIFICIAL HORIZON indicates at what angle the plane is climbing, descending or banking. This instrument is essential when a pilot can not see outside.

The VERTICAL SPEED INDICATOR tells the pilot how fast the plane is climbing or descending in feet per minute.

The COMPASS indicates magnetic heading.

Several other instruments are included in the handouts. Have the students do a little research to find out how they work and what they are used for.
Procedure:

1. Have the students carefully cut out the instrument faces from the sheets.
2. Glue the faces on tagboard.
3. Cut out the hands or dials which move and ..
4. Attach them to the instrument faces with brass fasteners.
5. Review with the students how to read the instruments using the activity sheets.
6. Have the students set the dials on the instruments they made to read at the same values as the instruments on the activity sheet.
7. Show the students some examples of different settings on a demonstration instrument and ask them to interpret what the setting or the reading means.
8. Prepare a list of possible instrument readings and have the students set their instruments to match the readings. Have the students check each other.
9. Have them identify which instruments are needed for flying VFR (on visual flight rules).
10. Have them identify the additional instruments needed for IFR flying (instrument flight rules) in bad weather or through clouds.

Extensions:

Have the students prepare a mock-up of a plane’s control panel complete with radios. Have them research and add to the panel, instruments which are found on more expensive planes, then, explain their function to the class. Take a trip to a local airport and see the actual instruments in a plane. Have a pilot or air traffic controller come to the class and talk about the instruments and flying. Arrange for a flight to see the instruments and controls in use. (See activity # 8).
Instrument Panel

Airspeed indicator. Gyroscopic compass. Artificial horizon. Altimeter Turn-and-bank indicator. Vertical speed (rate-of-climb and descent) indicator. VHF navigation – communication radio. Fuel gauge (left tank) Oil pressure gauge. Oil temperature gauge. Fuel gauge (right tank). Suction indicator (run by vacuum pump, which activates gyroscopic instruments). Tachometer (measures revolutions per minute of propeller). Battery – generator indicator. Clock. Control wheel (dual). Rudder pedals. Carburetor heat control. Throttle control. Fuel-air mixture control. Wing flaps control. Trim tab control. Magnetic compass.
INSTRUMENT ANSWER SHEET

THE COMPASS

The magnetic compass is used in airplanes is a simple self contained instrument. A “compass card” is mounted on a floating ring which has two magnetized needles, which always point to magnetic north. The compass card has letters for cardinal headings, that is, N (north), E (east), S (south) and W (west). Each 30° interval of direction is represented by a number from which the last zero is omitted. Between the numbers, the card is graduated for each 5°. For example, on the compass 240° would look like 24.
INDICATED ALTITUDE

The AIRSPEED INDICATOR is similar to a speedometer in a car. It shows the speed the airplane is traveling through the air.