Aircraft Operations

II-4-1-4
Procedures — Aircraft Operations — Volume I
a) a conventional RNAV non-precision procedure and APV/LNAV OCA/H are promulgated for the approach; and
b) the appropriate cold temperature altimeter correction is applied to all minimum promulgated altitudes/heights
by the pilot.
1.4.3 A VPA deviation chart may be published on baro-VNAV instrument procedure charts, correlating an
aerodrome temperature with an associated true VPA. This chart is intended to advise flight crews that although the nontemperature
compensated aircraft’s avionics system may be indicating the promulgated final approach VPA, the actual
VPA is different from the information presented to them by the system.
1.4.4 This chart is not intended to have the pilot increase or decrease the VPA flown to achieve the actual
promulgated VPA. A sample of the chart is provided in Table II-4-1-1.
1.4.5 Some baro-VNAV systems have the capability to correctly compensate the VPA of an instrument approach
procedure following an input of the aerodrome (altimeter source) temperature by the pilot. Pilots operating aircraft with
this feature active are expected to ignore the VPA chart and fly the system-corrected VPA guidance.
1.4.6 Altimeter setting
Baro-VNAV procedures shall only be flown with:
a) a current local altimeter setting source available; and
b) the QNH/QFE, as appropriate, set on the aircraft’s altimeter.
Procedures using a remote altimeter setting source cannot support a baro-VNAV approach.
1.4.7 Vertical guidance sensitivity
1.4.7.1 The baro-VNAV vertical guidance display sensitivity varies with different equipment. However, cockpit
displays showing vertical path deviation must be suitably located and have sufficient sensitivity to enable the pilot to
limit vertical path excursions to less than:
a) +30 m (+100 ft); and
b) –15 m (50 ft)
from the VPA.
1.4.7.2 Vertical path deviation
Where equipment does not meet these criteria, an operational assessment and specific flight crew procedures may be
required for the approval of baro-VNAV operations. This may include requirements for the availability and use of a
flight director or autopilot system.
Note.— Some existing baro-VNAV vertical path deviation displays have a graphic scale where 2.5 cm (1 inch)
represents 121 m (400 ft), and such arrangements make it difficult for a pilot to meet the path keeping tolerance
requirements.
23/11/06