You can gain access to the machinery by removing the cover.

The lighting subsystems used to provide illumination outside of the aircraft, including lights such as landing, navigation, position indicating, wing illumination, rotating, taxi, etc.

That portion of the system which is used to extend and retract the landing gear and open and close the landing gear doors. Includes items such as actuating mechanisms, bogie trim, bungees, up and down latches, operating controls, valves and motors, cables, plumbing, etc.

The units and components are used for recording data not related to specific systems, including items such as flight recorders, performance or maintenance recorders, etc.

The portion of the system is used to indicate the quantity, temperature and pressure of the hydraulic fluid, including items such as transmitters, indicators, warning systems, etc.

The portion of the system which is used to store and deliver hydraulic fluid to using systems. Includes items such as tanks, accumulators, valves, pumps, levers, switches, cables, plumbing, external connectors, etc. Does not include the supply valves to the using systems.

Hydraulic systems include the units and components which furnish hydraulic fluid under pressure (includes pumps, regulators, lines, valves, etc.) to a common point (manifold) for redistribution to other defined systems.

Fuel system also includes integral and tip fuel tank leak detection and sealing. Does not include the structure of integral or tip fuel tanks and the fuel cell backing boards, and does not include fuel flow rate sensing, transmitting and/or indicating.

That portion of the systems includes items such as control handles, cables, actuators, warning systems, linkages, control surfaces, position indicators, etc.

That portion of the systems which controls the position and movement of the rudder and rudder tabs. Includes items such as the rudder pedals, tab control wheel, cables, boosters, linkages, control surfaces, position indicators, etc., as applicable.

The schematic diagram should tend to deal with an overall system rather than with subsystems, e.g., the air conditioning system rather than a compressor within the air conditioning system.