A probe , comprising: a housing adapted to be secured in a borescope port of a gas turbine engine high-pressure turbine , wherein the housing includes at least one passage , wherein the at least one passage comprises first and second transverse passages, the first passage comprising an inlet configured to be in fluid communication with a coolant source , and is configured to conduct a coolant from the coolant source through the housing , wherein the coolant source comprises a plenum ; at least one sensor carried by the housing in a turbine gas flow (A, C) of the high pressure turbine of the gas turbine engine during working operation thereof, wherein the at least one sensor is further configured to be in fluid communication with the coolant; wherein the at least one sensor comprises first and second sensors , wherein the first sensor comprises a temperature sensor embedded in the housing which is configured to develop a signal T metal representing the temperature thereof at a location within the high-pressure turbine , and wherein the second sensor comprises a pressure tap disposed adjacent to the at least one passage embedded in the housing and configured to be exposed to the flow of coolant in the at least one passage and to develop a signal P S(passage) representing the static pressure of the coolant in the at least one passage ; and the at least one sensor further comprises third and fourth sensors for developing signals T coolant and P T(coolant) respectively, wherein T coolant and P T(coolant) represent the temperature and total pressure, respectively, of the coolant in the plenum ; wherein the probe further comprises a data acquisition unit to which the signals T metal , P S(passage) , T coolant , and P T(coolant) are provided, the data acquisition unit comprising a programmable processing device configured to execute programming to determine whether the inlet of the passage is blocked by checking the signals. a housing adapted to be secured in a borescope port of a gas turbine engine high-pressure turbine , wherein the housing includes at least one passage , wherein the at least one passage comprises first and second transverse passages, the first passage comprising an inlet configured to be in fluid communication with a coolant source , and is configured to conduct a coolant from the coolant source through the housing , wherein the coolant source comprises a plenum ; at least one sensor carried by the housing in a turbine gas flow (A, C) of the high pressure turbine of the gas turbine engine during working operation thereof, wherein the at least one sensor is further configured to be in fluid communication with the coolant; wherein the at least one sensor comprises first and second sensors , wherein the first sensor comprises a temperature sensor embedded in the housing which is configured to develop a signal T metal representing the temperature thereof at a location within the high-pressure turbine , and wherein the second sensor comprises a pressure tap disposed adjacent to the at least one passage embedded in the housing and configured to be exposed to the flow of coolant in the at least one passage and to develop a signal P S(passage) representing the static pressure of the coolant in the at least one passage ; and the at least one sensor further comprises third and fourth sensors for developing signals T coolant and P T(coolant) respectively, wherein T coolant and P T(coolant) represent the temperature and total pressure, respectively, of the coolant in the plenum ; wherein the probe further comprises a data acquisition unit to which the signals T metal , P S(passage) , T coolant , and P T(coolant) are provided, the data acquisition unit comprising a programmable processing device configured to execute programming to determine whether the inlet of the passage is blocked by checking the signals. <EOS>