General Authority of Civil Aviation (GACA) Aeronautical Information Publication (AIP) Practice Exam

How can fuel jettisoning be terminated?

1. By turning off the APU

2. By selecting the ARM switch to OFF or both nozzles to OFF

3. By adjusting the fuel pumps

4. By shutting down the engines

The correct answer is: By selecting the ARM switch to OFF or both nozzles to OFF

The process of fuel jettisoning involves the controlled release of fuel from an aircraft to reduce weight, particularly for landing within maximum weight limits. To terminate or stop the jettisoning of fuel, one effective method is by selecting the ARM switch to OFF or by setting both nozzles to OFF. This action directly disconnects the system that controls the fuel release, thereby stopping the jettisoning. The ARM switch typically manages the functionality of the jettisoning system, while the nozzles regulate the flow of fuel being released. Other options may not effectively terminate fuel jettisoning. For instance, turning off the APU does not affect the fuel jettison system directly, and adjusting the fuel pumps could potentially lead to unintentional operational changes in other fuel systems without stopping the jettison process. Shutting down the engines would typically lead to more severe operational and safety concerns than merely stopping fuel jettisoning, as it affects the entire operation of the aircraft during flight. Therefore, option B accurately reflects the correct procedure for terminating fuel jettisoning in a safe and controlled manner.