Final answer:
The hand signal for releasing air brakes in automotive technology involves extending the arm out horizontally and moving the hand up and down. This signal is used to communicate that the air brakes can be released and the vehicle can start moving.
Step-by-step explanation:
The hand signal for releasing air brakes in automotive technology is to extend the arm out horizontally and move the hand up and down repeatedly. This signal is commonly used when working with trucks and other vehicles equipped with air brake systems.
By making this hand signal, the person is indicating to the driver that the air brakes can be released, allowing the vehicle to start moving. This signal ensures clear communication between the person giving the signal and the driver.
It is important to use hand signals for the release of air brakes because in certain situations, vehicle operators may not be able to hear verbal instructions due to engine noise or other factors.