Fuel transfer system for aircraft

An auxiliary fuel management system for an aircraft comprising:

• a main fuel tank;
• an internal main tank pipe terminating within said main tank and extending to the exterior of said main tank;
• an auxiliary tank;
• a plurality of transfer pumps in parallel flow relationship;
• a main tank shutoff valve with a first side connected to the end of the exterior portion of said internal main tank pipe;
• a pump discharge pipe connected between the discharge of said pumps and said internal main tank pipe;
• an auxiliary tank pipe connected between said auxiliary and a second side of said main tank shutoff valve;
• a pump suction pipe connected to said auxiliary flow pipe and the suction of said pumps;
• a main tank level sensor;
• a pressure sensor located in said pump discharge pipe;
• main tank level rate means for determining the rate of change of main tank level in response to said main tank level sensor;
• transfer initiation means operative in response to an initiating signal to close said main tank shutoff valve and to energize one of said pumps;
• a first pump timer logic means responsive to said pressure for detecting pressure above a preselected level within a first preselected time, and for establishing a first pressure sensed signal or a first pressure not sensed signal;
• pump switch logic means responsive to said first pressure not sensed signal for energizing another of said pumps;
• second pump timer logic means responsive to said pressure sensor for detecting pressure above a preselected level within a second preselected time for establishing a second pressure sensed signal or a second pressure not sensed signal;
• confirmation logic means responsive to said first or second pressure sensed signals and to said main tank level rate means for confirmation of the existence of flow when the main tank level is increasing at at least a preselected rate;
• and
• no flow alarm means responsive to said confirmation logic means for alarming in the absence of confirmation when the main tank level is not increasing at at least the preselected rate.