Spark plug for combustion chamber of a gas turbine engine

A turbine engine with combustion chamber comprising a spark plug comprising:

• an external body forming a ground electrode, said external body having a thickness;
• an internal central electrode;
• and
• an interposed electrical insulator interposed between the external body and the internal central electrode with a first clearance between the interposed electrical insulator and the external body, and a second clearance between the interposed electrical insulator and the internal central electrode,
• said spark plug terminating in a nose forming portion, and a semi-conductor element is interposed between the internal central electrode and the ground electrode at a level of said nose forming portion,
• said spark plug being received in a bypass of the combustion chamber, the nose forming portion being received in a flame tube of the combustion chamber,
• the external body comprising at least one cooling air inlet which communicates inside the spark plug with at least one outlet arranged at the level of the nose forming portion,
• wherein the interposed electrical insulator comprises at least one air inlet, the at least one air inlet emerging into a space forming the second clearance between the interposed electrical insulator and the internal central electrode, cooling air being introduced between the interposed electrical insulator and the internal central electrode in contact with the internal central electrode and discharging at the level of the nose forming portion of the spark plug via the clearance between said internal central electrode and the semi-conductor element.