The metering plug decreases the fuel flow.

For turbine engines, those units and components and associated mechanical systems or electrical circuits which furnish or control fuel to the engine beyond the main fuel quick disconnect; and thrust augmentor, fuel flow rate sensing, transmitting and/or indicating units whether the units are before or beyond the quick disconnect.

Those units and components are used to distribute oil throughout the engine, including front and rear pressure and scavenger pumps, sumps, strainers, valves, etc. Also includes those oil lines not included in Chapter 79.

The engine compressor control system is used to both control the flow of air through the engine and facilitate the operation of variable stator blades, and is comprised of several components such as governors, valves, actuators, and linkages.

The turbine engines include compressor bleed systems used to control flow of air through the engine, cooling air systems, heated air systems for engine anti-icing, and engine starting systems.

The anti-icing system of the engine eliminates and prevents ice formation by bleed air in all parts of the engine (excluding power cowling), and is inclusive of several components such as valves, plumbing, regulators, etc.

The engine power control system furnishes a means of controlling the main fuel control or coordinator, which includes controls to the propeller regulator on turbo-prop engines.

Doors refer to those removable units used for entrance or exit, and for enclosing other structure contained within the fuselage, including passenger and crew doors, cargo doors, emergence exits, etc. Electrical and hydraulic systems associated with door control are included as appropriate.

Airborne Auxiliary Power are those airborne power plants (engines) which are installed on the aircraft for the purpose of generating and supplying a single type or combination of auxiliary electric, hydraulic, pneumatic or other power.

Vacuum subsystems are those units and components used to generate, deliver and regulate below atmospheric pressure air, including pumps, regulators, lines, etc., through and including the manifold.

Position Computing refers to that portion of the system which combines navigational information to compute the aircraft＇s geographical location, including items such as course computers, etc.