A gas turbine engine particulate ingestion detection system, comprising: a first particulate sensor mounted at a first position on the gas turbine engine, the first position located at a first side of a gas turbine engine component, the first particulate sensor configured to sense number, size, and type of particulate at the first position and supply first data representative thereof; a second particulate sensor mounted at a second position on the gas turbine engine, the second position located at a second side of the gas turbine engine component and downstream of the first position, the second particulate sensor configured to sense number, size, and type of particulate at the second position and supply second data representative thereof; and a processor coupled to receive the first and second data from the first and second particulate sensors, respectively, the processor configured, upon receipt of the first and second data, to determine, based at least on the number, size, and type of the particulate at the first and second positions, a mass of the particulate accumulated on the gas turbine engine component; a source of aircraft environmental data configured to provide data representative of environmental parameters; a memory storing densities of particulate types, the densities varying based on environmental parameters including one or more of ambient temperature, ambient pressure and aircraft altitude; wherein the processor is configured to determine the mass of the particulate accumulated on the gas turbine engine component by multiplying the number of at least one type of particulate that has passed by the first particulate sensor during a predetermined sampling time period with the size of the at least one type of particulate and with a density associated with the at least one type of particulate to obtain a first value, and then multiplying the number of the at least one type of particulate that has passed by the second particulate sensor during a predetermined sampling time period with the size of the at least one type of particulate and with a density associated with the at least one type of particulate to obtain a second value; and subtracting the second value from the first value to obtain a mass of the at least one type of particulate that has accumulated on the gas turbine engine component during the predetermined sampling time period. a first particulate sensor mounted at a first position on the gas turbine engine, the first position located at a first side of a gas turbine engine component, the first particulate sensor configured to sense number, size, and type of particulate at the first position and supply first data representative thereof; a second particulate sensor mounted at a second position on the gas turbine engine, the second position located at a second side of the gas turbine engine component and downstream of the first position, the second particulate sensor configured to sense number, size, and type of particulate at the second position and supply second data representative thereof; and a processor coupled to receive the first and second data from the first and second particulate sensors, respectively, the processor configured, upon receipt of the first and second data, to determine, based at least on the number, size, and type of the particulate at the first and second positions, a mass of the particulate accumulated on the gas turbine engine component; a source of aircraft environmental data configured to provide data representative of environmental parameters; a memory storing densities of particulate types, the densities varying based on environmental parameters including one or more of ambient temperature, ambient pressure and aircraft altitude; wherein the processor is configured to determine the mass of the particulate accumulated on the gas turbine engine component by multiplying the number of at least one type of particulate that has passed by the first particulate sensor during a predetermined sampling time period with the size of the at least one type of particulate and with a density associated with the at least one type of particulate to obtain a first value, and then multiplying the number of the at least one type of particulate that has passed by the second particulate sensor during a predetermined sampling time period with the size of the at least one type of particulate and with a density associated with the at least one type of particulate to obtain a second value; and subtracting the second value from the first value to obtain a mass of the at least one type of particulate that has accumulated on the gas turbine engine component during the predetermined sampling time period.