What is the low fuel pressure threshold for the FUEL 1 PRESS LOW caution?

What is the low fuel pressure threshold for the FUEL 1 PRESS LOW caution?

• A. 12 Psi
• B. 5 Psi
• C. 15 Psi
• D. 9 Psi

Answer: (D)

Fuel pressure in the FUEL 1 line has a defined low-limit signaling a risk of fuel starvation. The FUEL 1 PRESS LOW caution is set to trigger at 9 psi, which gives the crew early warning before the engine experiences improper metering or flameout due to insufficient fuel flow. This threshold is chosen to differentiate normal minor fluctuations from a real loss of supply, allowing time to check for pump or line problems or to switch to an alternate fuel source if available. Pressures around 12 psi would still be considered acceptable, 5 psi would indicate a more severe condition than the warning is intended to address, and 15 psi is well above the low-pressure concern. Therefore, 9 psi is the correct threshold.

Fuel pressure in the FUEL 1 line has a defined low-limit signaling a risk of fuel starvation. The FUEL 1 PRESS LOW caution is set to trigger at 9 psi, which gives the crew early warning before the engine experiences improper metering or flameout due to insufficient fuel flow. This threshold is chosen to differentiate normal minor fluctuations from a real loss of supply, allowing time to check for pump or line problems or to switch to an alternate fuel source if available. Pressures around 12 psi would still be considered acceptable, 5 psi would indicate a more severe condition than the warning is intended to address, and 15 psi is well above the low-pressure concern. Therefore, 9 psi is the correct threshold.