XPDR 5537 IDNT LCL23:00:34  GPS TERM  197 °  357 ° HDG  152 ° CRS  2  1  1  2  2 300  2 200  2 100  4 000  1 900  1 800  1700  3600  3500  3400  3300  3200  3100  60 20 2 000 000  150  140 130 110 100 90  1 120 9 TAS 120KT  OAT 7°C  ALERTS  NAV1 108.00 113.00 NAV2 108.00 110.60 134.000 118.000 COM1 123.800 118.000 COM2 $_{WPT }$_ _ _ _ _ _$_{ DIS }$_ _ ._ $_{NM}$ $_{DTK }$_ _ _$_{°}$ TRK 360° TRAFFIC Heading 1/2 standard rate Standard rate Turn rate trend vector VOR1  197 °  357 ° HDG  152 ° CRS  Heading 1/2 standard rate Standard rate Turn rate trend vector Figure 4-35. HSI Trend Indicator elongates proportionate to the rate of turn.  Figure 6-38.  Horizontal situation indicator (HSI) trend indicator elongates proportionally with the rate of turn. 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.  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  not the only tools to aid the pilot in maintaining the desired  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  Figure 4-36. Figure 6-39.  HSI indicator (enlargement). Common Errors Fixation 6-27