ILS Landing - how?

[pegase]

The plane turns onto the right heading but it doesnt accept the glideslope

It highly depends on the plane you fly because

To follow the glide slope when intercepted. The requirements are depending upon the autopilot grneration.
the default FS2004 and most current planes, when you engage the approach mode, the altitude hold mode remains active until the glide
slope is intercepted, then it is automatically disengaged to follow the glide slope.

On older planes like the 727 having a Sperry SP50, the altitude control can be on or off with the elevator control switch and has two on
modes.
- By default it just keep a given pitch, up to the pilot to set the pitch depending on the current air speed (there is no speed hold) and the
wished verical speed
- Current altitude hold mode activated by a altitude hold switch it keeps the altitude when activated and has priority until disengaged by
the pilot.. So, just before glide slope interception, the altitude hold mode must be switched off while elevator control switch must remains
on. Then tt will follow the glide slope.

In any case, you must be at stable altitude and approach speed quite before interception. Usually with a jetliner (160-180 kts) at 2000-
3000 feets AGL is OK.

Hope it helps, happy landings to all