MGL Avionics User Forum

I’ve just been setting up and learning the internal AP in the MX1. So far I’m very impressed with the servos (particularly the low torque when turned off) and the programming of the system. I’m wanting to experiment with the ‘synthetic GPS based ILS’ however I can’t work out what [Glide slope control] means in the AP pitch settings. The default is zero and it wants integers as the setting. I don’t think it is the glide slope angle as you set that in another spot. Any ideas?

The glide slope angle and intercept point (distance from threshold you would like to crash into the runway) you select in the GLS setup.

The glideslope setting in the AP pitch control is a factor that is used to determine how "forcefully" to intercept and follow the glideslope down. Start with the default - that should be OK for most applications. If you find it's a bit sloppy (i.e. the "pilot" is too timid) increase the number. Generally the faster the aircraft the more control may be needed - I am saying "may" as this depends on the aircraft, how the controls are coupled and how effective this are at slower speeds in the circuit.

There is also the GS maneuver start setting - this tells the AP when to start dropping the nose in order to intercept the glide slope. 1/2DDM (the default) means when your glide slope needle has traveled half way to the center. Faster aircraft may need to start the maneuver earlier to avoid overshoot.

Once the maneuver starts you need to use your power setting to control speed as the AP has no control here.

At a safe height and distance from the touch down point - disengage the AP and take over the remainder of your landing.

Check your missed approach trigger RPM setting (in GLS setup). Set this to just below your full power RPM. This way should you want to abort the approach - just floor the throttle. The AP will then abort and switch to maintain heading and initiate a climb.

In order for the AP to follow a glide slope make sure the GLS is active - the row of crosses you see down to the runway on the screen will be green to indicate this. If the crosses are blue/white these are just passive guides to runways (there could be more than one of these shown). Your EFIS hunts for potential runways in the database and if one is found will provide approach guidance (just in case). You can activate the nearest one in the NAV menu as active GLS.
Otherwise you can active any GLS either direct or via intercept (set your desired intercept distance in the GLS setup menu - this is the equivalent of a FAF (final approach fix) - a value of 3-5 miles is usually about right). Go to "nearest airfields" - pick the one you are interested in and select the runway and then activate the GLS or intercept.

Thanks.