Document ID: chunk:federal_register_of_legislation:F2005L04061:body:0:p22
Version: federal_register_of_legislation:F2005L04061
Segment Type: other
Provision Reference: 
Character Range: 57667–60515

aircraft's position.

4.3.3 Explanation of terms and standards

       4.3.3.1The display of navigation data must use a lateral deviation display or a navigation map display.

       4.3.3.2A non-numeric lateral deviation display (eg course deviation indicator (CDI)), electronic horizontal-situation indicator ((E)HSI) with a To/From indication and a failure annunciation, for use as primary instruments for the navigation of aircraft, for manoeuvre anticipation and for failure or status or integrity indication, must:

 (a) be visible to the pilot and located in the primary field of view (± 15° from the pilot's normal line of sight) when looking forward along the flight path; and

 (b) if implemented, have lateral scaling that agrees with any alerting and annunciation limits; and

       (c) either:

 (i) be automatically slaved to the RNAV computed path, have a full-scale deflection suitable for the current phase of flight and be based on the required track-keeping accuracy; or

 (ii) allow the pilot to change the CDI or HSI selected course to the computed desired track; and

       (d) have display scaling:

 (i) that is set automatically by default logic or set to a value obtained from the navigation database; and

 (ii) for which the full-scale deflection is known or available for display to the pilot and commensurate with the en-route, terminal or approach phase of flight values.

       4.3.3.3A navigation map display must:

 (a) be readily visible to the pilot; and

 (b) have appropriate map scales (scaling may be set manually by the pilot); and

 (c) give equivalent functionality to a lateral deviation display.

       4.3.3.4The track to fix (TF) leg is a geodesic path between 2 fixes:

(a) the first fix is the previous leg termination or an IF leg; and

(b) the termination fix is normally provided by the navigation database, but may also be a user-defined fix.

       4.3.3.5The direct to fix (DF) leg is a geodesic path starting near the area of initiation and terminating at a fix.

       4.3.3.6 The Direct-To function must:

(a) be able to be activated by the crew at any time; and

(b) be available to any fix; and

(c) be capable of generating a geodesic path to the designated To fix; and

(d) enable the aircraft to capture this path without S-turning or undue delay.

        4.3.3.7The course to fix (CF) leg is a geodesic path terminating at a fix with a specified course at that fix.

       4.3.3.8The inbound course at the termination fix and the fix are provided by the navigation database.

       4.3.3.9If the inbound course is defined as a magnetic course, the source of the magnetic variation needed to convert magnetic courses to true courses is required.

      4.3.3.10 The system requirements for a parallel offset are:

(a) the capability to fly parallel tracks at a selected offset