Basic Cable Coding System

(1)           (2)               (3)       (4)       (5)                     (6)

 1         E         F          6          B         22              NMS   V

Position 1	Unit number, used where components have identical circuits.
Position 2	Circuit function letter and circuit designation letter which indicate circuit function and the associated system.
Position 3	Cable number, allocated to differentiate.
Position 4	Cable segment letter, which identifies the segment of cable between two terminals or connections, and differentiates between segments of the circuit when the same cable number is used throughout.  Segments are lettered in alphabetical sequence, excluding the letter I and O.  A different letter is used for each of the cable segments having a common terminal or connection.
Position  5	Cable size.
Position 6	Suffix data, used to indicate the type of cable and to identify its connection function.  For example, in the example code NMS V indicates nyvinmetsheath ungrounded cable in a single-phase system.

Air Data Computer-Anologue

The air data computer (ADC) is an additional and improved means of supplying the pilot and co-pilot with airspeed, altitude, vertical speed and mach number.  Previously, air pressure was supplied to the primary pitot/static flight instruments by long lengths of P/S pipelines.  To minimize these, a central unit was developed where the pitot and static pressures could be fed. This unit is known as ‘The Centralized Air Data Computer’.  The outputs from the CADC are in the form of synchro signals therefore, the CADC may be referred to as being an analogue device.  These are still widely used, although later generation aircraft have switched to digital units.

The simple pitot static system is still fitted in almost all aircraft and will be used as a safety/comparison factor against the CADC and vice versa.  Two independent CADC systems would be installed, the input to each would be from independent sources for safety reasons.

A modular arrangement is shown along with a typical transmission system. 

Aircraft Antennas

Air carrier operations ideally require uninterrupted communications between both air traffic control agencies, and company operations, and/or out-station handling agents.  Much of these communications are achieved by voice, using either short range VHF, or HF for long distance communications.  This situation is changing in that information is being digitized and routed over data links including satellites with print-outs available as required.  The antenna map shows the typical equipment installed in a modern jet transport for communication purpose.

 

Obviously there are many equipment manufacturers producing communications and navigation equipment.  In these lessons no attempt is made to portray any specific type, and the diagrams should be regarded as typical of the many and various models available.