Airplane Flight Manual Supplement

Hawker Beechcraft 200, 200C, B200, B200C, 190-00915-02 Rev. 8
B200GT and B200CGT King Air
Page 170 of 179
In Figure 25 below, the approach plate notes for the same approach indicate it was designed to allow the
approach to be safely flown within a temperature range of 2°F to 114°F. Outside of this temperature range,
LNAV/VNAV minimums could not be used with uncompensated
baro-VNAV systems.
Figure 25 – Approach Plate Notes
The Garmin G1000 Approach Baro VNAV system is automatically temperature compensated to produce a
glidepath position in space such that Baro VNAV approaches are always flown at the published glide path
angle when the actual temperature deviates from the ISA model. This produces results similar to ILS
glideslopes and LPV glidepaths that remain in the same position in space without respect to temperature.
To produce the correct geometric glide path angle on the final approach segment, temperature
compensation is applied to the barometric altitude and used to determine the displayed vertical deviation.
However, the altimeter continues to display uncompensated barometric altitude. The temperature
compensation required depends on the temperature profile over the altitude range between the point at
which the barometric setting is measured (presumed to be the approach airport) and the present altitude of
the aircraft. This temperature profile is estimated by using the air data system static air temperature (SAT)
and applying the standard temperature lapse rate to determine the temperature over the rest of the range.
When using barometric altitude for vertical guidance along the final approach segment, temperature
compensation is applied whether the temperature is above or below standard temperature. The actual
compensated altitude is not displayed to the pilot during an approach.
Compensating Waypoint Altitudes
In some locales, temperature compensation is required for waypoints in the approach prior to the final
approach segment due to terrain and/or obstacle clearance requirements. Currently, US operations do not
require use of temperature compensated waypoint altitudes since non-standard temperature is factored
into the approach design. Pilots operating in US airspace must request and obtain ATC approval prior to
using temperature compensated waypoint altitudes since it may result in reduced vertical separation
between aircraft. However, other countries (e.g. Canada) may require use of temperature compensation
on certain procedures.
For the G1000 system, temperature compensation of waypoint altitudes on the active flight plan page is
pilot-enabled by a menu option on the FPL – ACTIVE FLIGHT PLAN MFD page. Selecting the menu
option displays a pop-up window to allow the pilot to enter the temperature at the destination that is
cross-filled to the other GDUs so that a consistent temperature is used for temperature compensation of
published approach waypoint altitudes and the approach minimum altitude. Refer to Figure 26. Enabling
temperature compensation of published approach waypoint altitudes on one display enables it on all
displays in the system. If compensation is already active, and the temperature matches the temperature
being used for compensation of waypoint altitudes, the field at the bottom of this pop-up page reads
“CANCEL COMPENSATION?”
Displayed waypoint altitudes should remain constant. Because the compensation may originally be
computed when the aircraft is at a much higher altitude than the approach waypoint altitudes, compensation
of published waypoint altitudes on the active flight plan page is based on the temperature reported at the
field elevation (rather than using the measured static air temperature at the aircraft altitude).