14 / 20
Precision RNAV (P-RNAV) requires a track-keeping accuracy of plus or minus..
  • A
    1.0 NM for 95% of the flight time.
  • B
    8.0 NM for 95% of the flight time.
  • C
    5.0 NM for 95% of the flight time.
  • D
    10.0 NM for 95% of the flight time.
RNAV 1 is the RNAV specification for Precision Area Navigation (P-RNAV). It requires a minimum navigational accuracy of ±1nm for 95% of the time.

Qualifying systems must have the ability to fly accurate tactical offsets; P-RNAV routes must be extracted directly from the FMS data base and must be flown by linking the R-NAV system to the FMS/autopilot. In addition, flight crews are restricted from manually adding waypoints to the route.

This level of navigation accuracy can be achieved using DME/DME, VOR/DME or GNSS. It can also be maintained for short periods using inertial reference systems (IRS) and the length of time that a particular IRS can be used to maintain P-RNAV accuracy without external update is determined at the time of equipment certification.

It should be noted that if GNSS is not used as a source then two independent ground-based sources are required to meet P-RNAV minimum requirements apart from specified short periods of INS ‘backup’, which is a more stringent requirement than for some older flight management system (FMS).
P-RNAV is used to provide more routes and terminal area procedures and may be used down to the final approach fix (FAF) on designated approach procedures.

Your Notes (not visible to others)

This question has appeared on the real examination, you can find the related countries below.