Figure 1-41.  An engine nacelle firewall. Figure 1-42.  Various aircraft engine mounts.  Figure 1-43.  Typical cowling for a horizontally opposed  reciprocating engine. opposed engine on a light aircraft. It is attached to the nacelle  by means of screws and/or quick release fasteners. Some  large reciprocating engines are enclosed by “orange peel”  cowlings which provide excellent access to components  inside the nacelle.  [Figure 1-44]  These cowl panels are  attached to the forward firewall by mounts which also serve  as hinges for opening the cowl. The lower cowl mounts are  secured to the hinge brackets by quick release pins. The side  and top panels are held open by rods and the lower panel is  retained in the open position by a spring and a cable. All of  the cowling panels are locked in the closed position by over- center steel latches which are secured in the closed position  by spring-loaded safety catches. An example of a turbojet engine nacelle can be seen in  Figure 1-45.  The cowl panels are a combination of fixed  and easily removable panels which can be opened and closed  during maintenance. A nose cowl is also a feature on a jet  engine nacelle. It guides air into the engine. The empennage of an aircraft is also known as the tail  section. Most empennage designs consist of a tail cone,  fixed aerodynamic surfaces or stabilizers, and movable  aerodynamic surfaces. The tail cone serves to close and streamline the aft end of  most fuselages. The cone is made up of structural members  like those of the fuselage; however, cones are usually of  lighter construction since they receive less stress than the  fuselage.  [Figure 1-46] Empennage  1-22