Can't manage ILS altitude please help

[Roberto Alfieri 0]

hello

 

i'm trying to land with my C90B in ils mode

i wait ATC to authorize me to land, so i switch up the correct freequency in NAV1 and click on the "NAV" button of the autopilot

 

my plane correctly lines with the correct approach but... dont fall! it stays at 4000 feets forever, flights perfectly lined up with the airport and continue up to the end of the universe

 

i've tried with the APP button, but no success

 

can someone say me what i'm doing wrong? Ciao and ty

[YEGspotter 0]

You need to have the altitude switch activated as well, if you want to fly the glideslope on an ILS approach. If your NAV radio and CRS heading are set correct, ensure that your HDG and ALT switches are also active (on). Once your aircaft intercepts the ILS, HDG and ALT will deactivate then it's simply up to you to maintain your desired approach airspeed...

[Roberto Alfieri 0]

First of alla TY

 

in any case you mean that i have to mantain HDG and ALT buttons on? NOT the NAV or APP?

in any case the ALT switch never goes off...

[Bert Pieke 7,586]

You can fly HDG or NAV, but should also have ALT enabled.

 

When the glideslope goes live on the HSI, you select APP.

 

You do have to approach the glideslope from below, or the

autopilot will not capture.

[Stanner 0]

Let start at the beginning. As you approach I assume you are flying the GPS, so you have the NAV and Altitude switch activated, as well as the autopilot.

 

To get the aircraft to fly an ILS you must first switch the from GPS to NAV. In some aircraft there is a GPS/NAV switch. I believe in the C90

the change is done on the Garmin by clicking on the CDI switch on the lower left hand side. Next you must change from NAV to HDG on Select Panel. When within 15 nm activate the APPR (approach) button.

Since you are on autopilot, the aircraft will now follow the Heading bug on the compass instrument. Therefore you need to make certain the Heading bug is set

to the correct course to intercept the ILS. You should also set the heading arrow on this instrument to the ILS heading. You then need to be at the correct

altitude to intercept the ILS. This altitude depends on the particular runway and airport. You need to consult the approach chart. If you do not have a chart

then use 3,200 feet. This means that you should approach the ILS at 3.200 feet. The distance from the airport runway apron that the ILS engages again depends

on the runway and airport. However this can vary from 9nm to 15 nm. Usually it is closer to 9nm. It is at this point that the autopilot should begin to

fly the ILS and you will note the altimeter descending.

If you are too high you will not intercept the ILS. Look at the small yellow triangle on the left side of the compass instrument (the one with the hdg bug and the course yellow arrow). If your aircraft has "captured" the ILS, this yellow triangle on the left will begin to descend towards the horizontal white line.

Also the yellow course arrow should begin to converge towards the short yellow line. This tells you that the aircraft is lining up with the runway. When the course yellow arrow lines up with the small yellow line, you are lined up to fly straight in to the runway. When the small yellow triangle on the left is lined up with the white horizontal line you are following the ILS down correctly.

At about 100 ft elevation, shut off your autopilot and auto throttle and manually fly the landing.

 

Stanner

[fppilot 4,390]

i wait ATC to authorize me to land, so i switch up the correct freequency in NAV1 and click on the "NAV" button of the autopilot

 

Wow! For someone once instrument rated this thread seems highly confusing to me. Bert is correct and has it simplified for you. However there is one more setting you must pay attention to.

 

You appear to know how to set up the ILS approach. You may have had most of it right. You have to switch the AP from NAV to APR after intercepting the ILS LOC and have the glideslope indicator live on the CDI. And as Bert stated you must intercept the slope from below. But if you are using the GPS (or have it powered up) you must also make sure you switch the GPS's CDI setting from GPS to VLOC. If the CDI setting of the GPS is set to GPS instead of VLOC it will track you right to the runway but will not track the ILS glide slope.