Radar
That is correct, there is no digital display of the altitude, however it is not necessary for glidepath and approach guidance.
If the aircraft is established on the correct glidepath angle and the correct azimuth, the primary radar return will be exactly on the graphic overlay for the extended centerline and the prescribed gidepath. Deviations can be observed from an expierenced radar controller and informations or intructions can be given to the aircrew. The range to the target can be seen as well on the range overlay.
At the beginning of the maximum range of the equipment larger deviations might pass unobserved, closer in small deviations will show on the scope.
Expierienced controllers also can observe trends, like being on glidepath but on the way to drop below glidepath e.t.c. Glidepath angle and range determine also the point of MDA, where the go around should be initiated.
With similar equipment our controllers talked us down to a published minimum of 60 meters with a visibility of 800 Meters , flown with approach speed / landing speed of 230 KIAS / 160 KIAS. But on the other hand, we had no better gadgets in our F4, we flew it manually and had been able to do the instrument crosschecks same time. And to make it sporty, the radar controllers could us handle in these WX conditions and with this old equipment also as twoship flying in close formation.
There is no magic in it, it can be done. Everything falls back on knowledge and expierience.
franzl
Last edited by RetiredF4; 20th Jan 2011 at 17:12.