A pump health monitoring system for a fuel pump for pumping fuel in a fuel tank of an aircraft, comprising: a pump sensor interface for receiving a value of one or more pump parameters relating to pump performance; an environment sensor interface for receiving a value of one or more environmental parameters selected from the group comprising: temperature, density, pressure, volume or head of fuel in the fuel tank; flow rate of fuel through the fuel pump; aircraft attitude; aircraft acceleration in one or more dimensions; and fuel pump acceleration in one or more dimensions; a storage device, wherein the storage device has stored therein: a reference environment containing a predetermined reference value of one or more of the environmental parameters corresponding to an in-flight condition for the aircraft fuel pump; and a set of instructions for: comparing a value of one or more of the environmental parameters received via the environment sensor interface to the predetermined value of the same environmental parameter(s) of the reference environment; and capturing a data set of instantaneous values including the one or more pump parameters and the one or more environmental parameters, if all the received environmental parameter values and the reference environmental parameter values match within a predefined range; and a processor configured to execute the set of instructions and to store a sample pump health indicator based on the captured data set. a pump sensor interface for receiving a value of one or more pump parameters relating to pump performance; an environment sensor interface for receiving a value of one or more environmental parameters selected from the group comprising: temperature, density, pressure, volume or head of fuel in the fuel tank; flow rate of fuel through the fuel pump; aircraft attitude; aircraft acceleration in one or more dimensions; and fuel pump acceleration in one or more dimensions; a storage device, wherein the storage device has stored therein: a reference environment containing a predetermined reference value of one or more of the environmental parameters corresponding to an in-flight condition for the aircraft fuel pump; and a set of instructions for: comparing a value of one or more of the environmental parameters received via the environment sensor interface to the predetermined value of the same environmental parameter(s) of the reference environment; and capturing a data set of instantaneous values including the one or more pump parameters and the one or more environmental parameters, if all the received environmental parameter values and the reference environmental parameter values match within a predefined range; and a processor configured to execute the set of instructions and to store a sample pump health indicator based on the captured data set. a reference environment containing a predetermined reference value of one or more of the environmental parameters corresponding to an in-flight condition for the aircraft fuel pump; and a set of instructions for: comparing a value of one or more of the environmental parameters received via the environment sensor interface to the predetermined value of the same environmental parameter(s) of the reference environment; and capturing a data set of instantaneous values including the one or more pump parameters and the one or more environmental parameters, if all the received environmental parameter values and the reference comparing a value of one or more of the environmental parameters received via the environment sensor interface to the predetermined value of the same environmental parameter(s) of the reference environment; and capturing a data set of instantaneous values including the one or more pump parameters and the one or more environmental parameters, if all the received environmental parameter values and the reference environmental parameter values match within a predefined range; and a processor configured to execute the set of instructions and to store a sample pump health indicator based on the captured data set.