Document ID: chunk:federal_register_of_legislation:F2005L04061:body:0:p21
Version: federal_register_of_legislation:F2005L04061
Segment Type: other
Provision Reference: 
Character Range: 55003–57993

and

 (iii) for which the INS or inertial reference unit (IRU) is approved in accordance with FAA Part 21 Appendix G).

    4.3.2 Technical requirements

       4.3.2.1Navigation accuracy has the following characteristics:

(a) it is defined relative to a geodesic path along a route or defined procedure;

(b) for RNP 4 operations, the maximum cross-track TSE, including PEE, FTE, PDE and display system error, is ±4 NM for 95% of the total flight time;

(c) the maximum along-track TSE is ±4 NM for 95% of the flight time.

       4.3.2.2GNSS monitoring has the following requirements:

(a) a GNSS navigation system must detect satellite failures before they cause the aircraft to exceed the defined airspace limits;

(b) this applies to all navigational uses of GNSS and is derived from overall effect of a GNSS failure;

(c) the standard for the probability of missed detection of satellite failures must be not more than 1 in 1000;

(d) for these failures of the navigation solution (or the horizontal alert limit (HAL)), the effective monitor limit must take into account:

 (i) other normal errors that may exist during the satellite fault; and

 (ii) the latency of the alert; and

 (iii) the crew reaction time to an alert; and

 (iv) the aircraft response;

(e) A HAL of 4 NM may be used to monitor GNSS failure for oceanic RNP 4 operations.

       4.3.2.3The following are mandatory functionalities:

(a) display of navigation data;

(b) track to fix (TF);

(c) direct to fix (DF);

(d) direct-to function;

(e) course to fix (CF);

(f) parallel offset;

(g) fly-by transition criteria;

(h) user interface displays;

(i) flight planning path selection;

(j) flight planning fix sequencing;

(k) user defined course to fix;

(l) path steering;

(m) alerting requirements;

(n) navigation data base access;

(o) geodetic reference system.

       4.3.2.4The following additional functionalities are recommended:

(a) display cross-track error on the CDU;

(b) display present position in distance or bearing to selected waypoints;

(c) provide time to waypoints on the CDU;

(d) display along track distance to the next waypoint;

(e) display ground speed;

(f) indicate track angle;

(g) provide automatic navigation aids selection;

(h) manually inhibit a navaid facility;

(i) automatic selection and tuning of DME or VOR, or both;

(j) estimate of position uncertainty;

(k) display current RNP level and type selection;

(l) capability to display flight plan discontinuity;

(m) display navigation sensor in use and display of degraded navigation.

       4.3.2.5Automatic radio position updating is the only method acceptable for the update of an 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