An aircraft fire and overheat detection system, comprising: a support bracket configured to secure the aircraft fire and overheat detection system to a component of an aircraft; a terminal assembly fixedly connected to the support bracket, the terminal assembly comprising a connection assembly and a connection cable, wherein the connection assembly comprises a mounting nut threaded onto a threaded barrel and a mounting head, wherein a portion of the support bracket is secured between the mounting nut and the mounting head; a sensing element electrically connected to the terminal assembly and arranged to detect at least one of fire and heat associated with the component of the aircraft, wherein the connection cable is electrically connected to the sensing element to enable detection of an electrical resistance in the sensing element; and a protective sleeve arranged about the connection assembly and connection cable, the protective sleeve comprising a first end having an opening and a second end having an opening and an interior bore extending between the openings at the first and second ends (310,314), wherein: a lug portion is arranged at the first end and includes a sealing protrusion extending radially inward within the interior bore, the lug portion having a first diameter (D 1), wherein the interior bore of the lug portion is sized to receive the connection assembly and the sealing protrusion is positioned and captured between the support bracket and the mounting nut, the sealing protrusion sealingly engaging between the threaded nut and the portion of the support bracket, a first wire portion having a second diameter (D 2) that is less than the first diameter (D 1) and extending toward the second end, and a second wire portion arranged at the second end, the second wire portion having a third diameter (D 3) that is less than the second diameter (D 2), wherein the third diameter (D 3) is sized to provide an interference fit with a portion of the connection cable. a support bracket configured to secure the aircraft fire and overheat detection system to a component of an aircraft; a terminal assembly fixedly connected to the support bracket, the terminal assembly comprising a connection assembly and a connection cable, wherein the connection assembly comprises a mounting nut threaded onto a threaded barrel and a mounting head, wherein a portion of the support bracket is secured between the mounting nut and the mounting head; a sensing element electrically connected to the terminal assembly and arranged to detect at least one of fire and heat associated with the component of the aircraft, wherein the connection cable is electrically connected to the sensing element to enable detection of an electrical resistance in the sensing element; and a protective sleeve arranged about the connection assembly and connection cable, the protective sleeve comprising a first end having an opening and a second end having an opening and an interior bore extending between the openings at the first and second ends (310,314), wherein: a lug portion is arranged at the first end and includes a sealing protrusion extending radially inward within the interior bore, the lug portion having a first diameter (D 1), wherein the interior bore of the lug portion is sized to receive the connection assembly and the sealing protrusion is positioned and captured between the support bracket and the mounting nut, the sealing protrusion sealingly engaging between the threaded nut and the portion of the support bracket, a first wire portion having a second diameter (D 2) that is less than the first diameter (D 1) and extending toward the second end, and a second wire portion arranged at the second end, the second wire portion having a third diameter (D 3) that is less than the second diameter (D 2), wherein the third diameter (D 3) is sized to provide an interference fit with a portion of the connection cable. a lug portion is arranged at the first end and includes a sealing protrusion extending radially inward within the interior bore, the lug portion having a first diameter (D 1), wherein the interior bore of the lug portion is sized to receive the connection assembly and the sealing protrusion is positioned and captured between the support bracket and the mounting nut, the sealing protrusion sealingly engaging between the threaded nut and the portion of the support bracket, a first wire portion having a second diameter (D 2) that is less than the first diameter (D 1) and extending toward the second end, and a second wire portion arranged at the second end, the second wire portion having a third diameter (D 3) that is less than the second diameter (D 2), wherein the third diameter (D 3) is sized to provide an interference fit with a portion of the connection cable.