NOTE: It is important to remember fundamental distinctions between the ADI display and the HUD. Using
a waterline symbol, the ADI displays instantaneous aircraft pitch attitude as measured from a pilot adjusted
pitch reference line. By contrast, the HUD displays a velocity vector symbol that shows the aircrafts
angular direction of movement as measured from a GINA-stabilized HUD horizontal flight line. When the
velocity vector is centered on the horizontal flight line, the aircraft is in level flight. The ADI and HUD
display are not synonymous. For example, it is quite possible to have a positive pitch angle displayed on
the pitch ladder while the GINA generates a negative or level flight velocity vector displayed on the HUD
flight path ladder (Figure 18).
Figure 18: TYPICAL ADI AND HUD DISPLAY IN THE LANDING PATTERN
NOTE: The ADI and HUD display different bank angle reference marks that must not be inadvertantly
(caret not displayed past 90o)
(caret flashes from 47.5o to 90o, not displayed past 90o)
Reaching the 90-degree position, increase your rate of descent to approximately 450 fpm. You should be
at 450 ft AGL and on-speed. Continue to adjust your AOB so that you will roll out on the extended runway
centerline. Use the entire runway as a reference for lineup, not just the landing area, to avoid angling or
overshooting approaches. You should have a visual howgozit during the approach turn, and you should
make any necessary corrections. At the 45-degree position, you should be at 325-375 feet AGL, and you
should be able to pick up the ball.
You enter the groove out of the start position at which point you should be at optimum AOA, trimmed up,
and on the runway centerline with 15-18 seconds of straightaway to touchdown. You should also have a
centered ball and approximately 500-700 fpm rate of descent.
NOTE: A slight power reduction will be required as you roll wings level in the groove. The optimum AOA
airspeed is 2 to 3 KIAS slower in wings level flight than it is during the turn. Failing to reduce the power will
cause you to go high, fast, or both. Even though the airspeed changes from the 180 through wings level in
the groove, you will still maintain optimum AOA throughout the approach turn.