Asked in Airplanes and Aircraft
How do you conduct ILS approaching and auto-landing and whats the difference between gpsnavapp in automatic pilot buttons?
I guess you are asking this for Flight Simulator. I don't consider using GPS for an approach for landing. It is much better accurate and safe to run an approach using NAV approach mode when it comes to an ILS. What you have to do is set the radios in order to intercept the localizer and run into an active glideslope.
Go on the airport, take the information about the ILS and memorize it. The information under ILS Heading should be put in the Course of the Autopilot. The ILS Frequency should be set in the NAV1 and NAV2 radios whilst having navigation set to NAV and NOT GPS in order to have the displays show the correct information and to have a good feed for the autopilot.
Once you have the radios set, follow the ATC's instructions until he gives you a fixed altitude to hold (usually 2,500 ft) and tells you to hold until intercepting the localizer. When in range the radios should give out beeps.When in range, set the autopilot APP switch to on and you will see that the plane will try to align with the runway. When running through the glideslope, the displays will show the aids to align in diamonds. Having the diamond centered both vertically and horizontally means you're aligned. If the plane has the autopilot still running, it will start a descent on its own towards the runway.
Having the AP handle the approach and descent doesn't mean you should be totally relaxed. Watch out for your landing checklist (gear down, flaps to 30/40 decrease depending). Check also that you maintain a constant speed holding it in a balanced way to keep level but avoiding stalling without going too fast. Watch out also for crosswinds etc as you might have to use rudder corrections in order to land the plane safely and correctly.
That would result in a full AP driven approach and landing, obviously disengaging the AP on touchdown in order to switch on the reversers and to take manual control (as the AP tends to have the elevators provide lift so when you touch down and take off again causing trouble for the stability of the plane).
This was mostly for Jets with computerised glideslopes. In planes like the Cessna you get two needles for a glideslope and the procedure is slight different.
Ps. I recommend that the last 500-800 feet of approach would be carried out with the AP off , providing full manual control
Good Luck and keep Flying