曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
Figure 4-37. Airspeed Indicators With No Trend Present.
Figure 4-38. Altimeter Trend Indicators.
aileron corrections. Verify the bank angle is correct and
continue scanning back to the yellow chevron.
Scan left to the airspeed tape and verify that the airspeed is
as desired, then return back to the center of the display. Scan
right to the altimeter tape. Verify that the desired altitude is
being maintained. If it is not, make the appropriate pitch
change and verify the result. Once the desired altitude has
been verified, return to the center of the display. Transition
down to the heading indicator to verify the desired heading.
When the heading has been confirmed, scan to the center of
the display.
It is also important to include the engine indications in the
scan. Individualized scan methods may require adjustment
if engine indications are presented on a separate MFD. A
modified radial scan can be performed to incorporate these
instruments into the scan pattern. Another critical component
to include in the scan is the moving map display located on
the MFD. To aid in situational awareness and facilitate a more
centralized scan, a smaller inset map can be displayed in the
lower left corner of the PFD screen.
Trend Indicators
One improvement the glass panel displays brought to the
general aviation industry is the trend vector. Trend vectors
are magenta lines that appear on the airspeed and altitude
tapes as well as on the turn rate indicator. These magenta
lines indicate what the associated airspeed, altitude, or
heading will be in 6 seconds [Figure 4-36] if the current
rate is maintained. The trend vector is not displayed if there
is no change to the associated tape and the value remains
constant [Figure 4-37] or if there is a failure in some portion
of the system that would preclude the vector from being
determined.
Trend vectors are a very good source of information for the
new instrument flight rules (IFR) pilot. Pilots who utilize
good scanning techniques can pick up subtle deviations
from desired parameters and make small correction to the
desired attitude. As soon as a trend is indicated on the PFD,
a conscientious pilot can adjust to regain the desired attitude.
[Figure 4-38]
Another advancement in attitude instrument flying is the turn
rate trend indicator. As in the cases of airspeed, altitude, and
vertical speed trend indicators, the turn rate trend indicator
depicts what the aircraft’s heading will be in 6 seconds. While
examining the top of the heading indicator, notice two white
lines on the exterior of the compass rose. [Figure 4-39] These
4-27
Figure 4-39. Horizontal Situation Indicator (HSI) Trend Indicator Elongates Proportionally With the Rate of Turn.
Figure 4-40. HSI Indicator (enlargement).
two tick marks located on both sides of the top of the heading
indicator show half-standard rate turns as well as standard
rate turns.
In Figure 4-40, when the aircraft begins its turn to the left,
the magenta trend indicator elongates proportionally with the
rate of turn. To initiate a half-standard rate turn, position the
indicator on the first tick mark. A standard rate turn would
be indicated by the trend indicator extending to the second
tick mark. A turn rate in excess of standard rate would be
indicated by the trend indicator extending past the second tick
mark. This trend indicator shows what the aircraft’s heading
will be in 6 seconds, but is limited to indicate no more than
24° in front of the aircraft, or 4° per second. When the aircraft
exceeds a turning rate of 25° in 6 seconds, the trend indicator
has an arrowhead attached to it.
Trend indicators are very useful when leveling off at a specific
altitude, when rolling out on a heading, or when stabilizing
airspeed. One method of determining when to start to level
off from a climb or descent is to start leveling at 10 percent
of the vertical speed rate prior to the desired altitude.
As the aircraft approaches the desired altitude, adjust the
pitch attitude to keep the trend indicator aligned with the
target altitude. As the target approaches, the trend indicator
gradually shrinks until altitude stabilizes. Trend indicators
should be used as a supplement, not as a primary means of
determining pitch change.
4-28
Common Errors
Fixation
Fixation, or staring at one instrument, is a common error
observed in pilots first learning to utilize trend indicators.
The pilot may initially fixate on the trend indicator and make
adjustments with reference to that alone. Trend indicators are
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
Instrument Flying Handbook仪表飞行手册上(76)
