PSA Airlines Canadair Regional Jet Systems (PSA-CRJ) Practice Exam

How is the motive flow for center tank fuel achieved?

1. Manual Operation

2. Gravity Ejector

3. Transfer Ejector Valve Activation

4. Crossflow Pump Engagement

The correct answer is: Transfer Ejector Valve Activation

The motive flow for center tank fuel is achieved through the activation of the transfer ejector valve. In the PSA-CRJ design, the transfer ejector system utilizes the pressure from the engine-driven fuel pumps to create a venturi effect, which effectively pulls fuel from the center tank into the main tanks. This method ensures that the fuel is transferred efficiently and helps maintain the balance of fuel between the tanks throughout the flight. The transfer ejector's operation is critical, especially during various phases of flight where fuel management plays a significant role in aircraft performance and balance. Utilizing the ejector system also minimizes the need for additional mechanical components, thus reducing weight and simplifying the system. Other methods like manual operation, gravity ejectors, and crossflow pumps are less effective or offer different functionalities. For example, manual operation would require crew intervention and isn't as efficient under varying flight conditions. Gravity ejectors depend on the position of the aircraft and are not suitable for consistent fuel movement. Crossflow pumps are typically used for fuel transfer between the main tanks but do not directly contribute to the center tank fuel motive flow in the same manner as the transfer ejector valve.