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. One improvement the glass panel displays brought to the  general aviation industry is the trend vector. Trend vectors  are colored lines that appear on the airspeed and altitude  tapes, as well as on the turn rate indicator. The color of  the line may vary depending on the airplane manufacturer. For example, on a Cirrus SR-20, the trend vector lines are  m a g enta and on the B-737 they are green. These colored lines  in d i cate what the associated airspeed, altitude, or heading  wi l l  be in 6 seconds for the Cirrus SR-20 and 10 seconds  fo r  t he B-737 if the current rate is maintained. The example  sh o w n in  Figure 6-35  uses the color and data that represents  th e  t rend vector for a Cirrus SR-20. The trend vector is not  di s played if there is no change to the associated tape and the  va l u e remains constant  [Figure 6-36]  or if there is a failure  in  s o me portion of the system that would preclude the vector  fr o m  being determined. 3400  3300  3200  3100  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 6-38]  These 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 6-39 , 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  Figure 6-37.  Altimeter trend indicators. Figure 4-32. Figure 6-35.  Airspeed trend indicators. Figure 6-36.  Airspeed indicators with no trend present. 150  140 130 110 100 90  1 120 9 TAS 120KT  Airspeed indicator showing stabilized  airspeed (no trend  indicator present). Trend Indicators Trend indicator shows altitude will be approxi- mately 1,780 ft in 6  seconds.  VSI arrow has moved up  to indicate a 1,500 fpm  rate of climb.  Note 1,500 fpm ÷ 60 sec = 25 ft  25 ft per sec x 6 sec = 150 ft  150 ft + 1,630 ft = 1,780 ft  2  1  1  2  1 5 00 1 900  1 800  1 700  1 600  1 500  1 400  4300  40 20 6  4 800  150  140 130 110 100 90  1 120 9 TAS 120KT  Airspeed trend indicator  shows airspeed will be  approximately 126 kts in  6 seconds. 6-26 90  120KT  Tr e n d vectors are a very good source of information for the  ne w instrument rated pilot(s). Pilots who utilize good scanning  tech niques can pick up subtle deviations from desired  para meters 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 6-37]