OBS N E S W 3 33 24 21 15 12 30 6 GS NAV OBS N E S W 3 33 24 21 15 12 30 6 GS NAV OBS N E S W 3 33 24 21 15 12 30 6 GS NAV I20 I00 90 40 II0 80 60 I30 I00 40 240 220 200 I80 I50 I20 I00 80 60 40 KNOTS 240 220 200 I60 I00 80 60 40 KNOTS – – OBS N E S W 3 33 24 21 15 12 30 6 GS NAV $^{90H}$z 150H z OBS N E S W 3 33 24 21 15 12 30 6 GS NAV Figure 11-110.  Components of an instrument landing system (ILS).  Glideslope 11-50 a turn to the left. This centers course deviation indicator on  the display and centers the aircraft with the centerline of the  runway. If the 90 Hz signal is received by the VOR receiver,  the CDI deflects to the right. The pilot must turn toward the  right to center the CDI and the aircraft with the runway center  line.  [Figure 11-111] The vertical guidance required for an aircraft to descend for  a landing is provided by the glideslope of the ILS. Radio  signals funnel the aircraft down to the touchdown point on  the runway at an angle of approximately 3°. The transmitting  glideslope antenna is located off to the side of the approach 