7. ELECTRICAL CIRCUITRY / AIRCRAFT LIGHTS

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: Several 45 minute periods
TYPE OF ACTIVITY: Student Investigation
TEACHING STRATEGY: Guided Discovery
CONCEPTS: Parallel Circuit Series Circuit Circuit Breaker
SKILLS: Construction Modeling Interpreting Data Reading Diagrams

Objectives: To have the students apply principles of circuitry to the wiring of a model aircraft; to become familiar with the clearance light lighting patterns used on aircraft and their meaning.

Materials: Model plane (preferably built by the student); Several feet of light wire (18 gage or less); small flashlight bulbs (at least three per plane though some students may use as many as 7); thin paint in red and green; toggle switches (optional); 2 – 1 1/2 volt dry cells per student; aircraft lighting specs (available from aircraft dealer or company) or a picture of an aircraft showing the lights.
Procedure:

1. Have the students investigate the lighting patterns of the aircraft they plan to use.
2. Have them draw a wiring diagram of the system they propose to use.
3. Have the students install the external lights on their scale model. These may include the wing clearance lights, the tail light, fuselage light or rotating beacon (a flashing light can be used here) and the landing lights.
4. Have the students arrange their wiring so that all of the wires are inside the aircraft and not exposed.
5. Have the students prepare to discuss the position and purpose of each of the lights in their system.

Extension: Depending on the equipment you may have in your classroom, you may wish to have the students compute the ohms and amperage of their circuits comparing the value of parallel vs. series circuits. You may wish the students to investigate the properties of “bi-metal” strips if they choose to use a flashing bulb to represent the rotating beacon. Note: A number of tiny bulbs are now on the market which will enhance the aesthetic quality of the finished product.