Non veni pacem mittere, sed gladium.
Is he changing the tail lights?
cleaning the carbon from the exhaust nozzles.here you find the aerodynamic "bullets" convair used to smooth the airflow at the tail. convair use the same idea on the 990 transport jets on the wing trailing edges behind the engine exhausts to smooth airflow and increase speed. better aerodynamic engineering and design eliminated the need in other designs. still, interesting factoid