I was having a bit of grief with this mission myself yesterday morning. I downloaded the fixed missions pack, even though I've got the latest game version installed, and I still got stuck at entering the ILS frequency.
Don't know if it helps you Anhedral but this is how I sorted it. If you read what the trainer says he tells you to scroll the MIDDLE MOUSE WHEEL to change the second dial to .30 if you just use left or rght mouse buttons all it does is change the volume on the dial.
It was so obvious but I was stuck there for ages.....doh!
Norrie..