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navigationposition fixing
3 – cru i s i ng CLASS G
TRACKKEEPING
Tolerances are applied to tracks to assess containment area for thepurposes
of ensuringnavigational integrity, separation fromother aircraft, terrain and
obstacle clearance and avoidanceof specified airspace. Although allowing
for theerrors inherent in thenavigational systemsused, these tolerances
arebasedon the assumption that thepilotwillmaintain track as closely as
possible.
Thepilot in commandmust, at all times, take positive action to regain track as
soon as a deviation from the correct track is recognised.
USEOFNAVAIDS
When using radio navigational aids as the primarymeans of navigation:
• the aircraftmust benavigated by reference to the aidwhich provides the
most precise track guidancewithwhich the aircraft is equipped and the
pilot is qualified to use; and
• only those aidswhich specifically define the relevant trackmust be used
for track keeping.
Theorder of precision isLocaliser, VOR, thenNDB/ Locator.When track
guidance isprovidedby radionavigationaids, but navigation isbyanapproved
self-containednavigationsystemor long rangenavigationsystem, thepilotmust
maintain trackasdefinedby themost accurate radionavigationaidavailable.
POSITION FIXINGWITHNAVAIDS
Apositive radiofix isone that isdeterminedby thepassageof the aircraft over:
• aNDB; or
• a VOR station; or
• aDME; or
• is one determined byGPSmeeting the equiptment and pilot
requirements; or
• is one determined by the intersection of twoormore position lineswhich
intersectwith angles of not less than 45degrees andwhich areobtained
fromNDBs, VORs, Localizers or DMEs in any combination.
For the purpose of this section, a position linemust bewithin the rated
coverage of the aidwith the exception that if a fix is determined entirely by
position lines fromNDBs, the position linesmust bewithin a range of 30 nm
from eachof theNDBs.