An aircraft propulsor comprising: an internal combustion engine comprising an intake , a combustion chamber coupled to the intake , and an exhaust coupled to the combustion chamber; a turbocharger coupled to the exhaust and configured to be powered by flow within the exhaust ; an injector coupled to the exhaust , disposed between the combustion chamber and the turbocharger , and configured to deliver fuel to a portion of the exhaust ; an igniter coupled to the exhaust , disposed between the combustion chamber and the turbocharger , and configured to ignite the fuel delivered by the injector to the portion of the exhaust ; one or more sensors to determine if the internal combustion engine has shut down during powering an aircraft; a controller configured to carry out the following steps: determining that the internal combustion engine has shut down during powering an aircraft; flowing , responsive to the determining that the internal combustion engine has shut down, air through the internal combustion engine to the exhaust by electrically motoring or windmilling the engine; delivering , with the injector , the fuel to the portion of the exhaust upstream of the turbocharger to create a mixture with the fuel and the air; igniting the mixture with the igniter ; and spooling , responsive to the igniting the mixture, the turbocharger for easier restarting of the aircraft propulsor. an internal combustion engine comprising an intake , a combustion chamber coupled to the intake , and an exhaust coupled to the combustion chamber; a turbocharger coupled to the exhaust and configured to be powered by flow within the exhaust ; an injector coupled to the exhaust , disposed between the combustion chamber and the turbocharger , and configured to deliver fuel to a portion of the exhaust ; an igniter coupled to the exhaust , disposed between the combustion chamber and the turbocharger , and configured to ignite the fuel delivered by the injector to the portion of the exhaust ; one or more sensors to determine if the internal combustion engine has shut down during powering an aircraft; a controller configured to carry out the following steps: determining that the internal combustion engine has shut down during powering an aircraft; flowing , responsive to the determining that the internal combustion engine has shut down, air through the internal combustion engine to the exhaust by electrically motoring or windmilling the engine; delivering , with the injector , the fuel to the portion of the exhaust upstream of the turbocharger to create a mixture with the fuel and the air; igniting the mixture with the igniter ; and spooling , responsive to the igniting the mixture, the turbocharger for easier restarting of the aircraft propulsor. determining that the internal combustion engine has shut down during powering an aircraft; flowing , responsive to the determining that the internal combustion engine has shut down, air through the internal combustion engine to the exhaust by electrically motoring or windmilling the engine; delivering , with the injector , the fuel to the portion of the exhaust upstream of the turbocharger to create a mixture with the fuel and the air; igniting the mixture with the igniter ; and spooling , responsive to the igniting the mixture, the turbocharger for easier restarting of the aircraft propulsor. <EOS>