Hello;I am trying to chnage coms frequncy on the 747, however, cannot seem to get the switch to read KSEA (110.30). The knob will not allow 110 to be dialled in.Is there something I am blatantly doing incorrectly?Thank you....IAIN

There are different mouse click areas around the knob itself to change both parts of the frequency. Just try to click around the area a bit and you should be able to find it.The click areas should also be outlined in the manual.

Hi MarcYes I've found the click areas on the panel and in the manual.The knob does not allow you to increment switch the 110 portion of 110.30 (KSEA). It will move the smaller digits (30) up and down, however the larger digits (100) will not move below 118.I

Ah, that's the problem - you are trying to dial in a VOR or ILS frequency. The frequency band for communications only goes to 118.For navigation frequencies, you will have to use the NAV/RAD page on the FMC.

YES THAT'S IT!!As always it's something simple.I haven't umm moved into the 747 FMC area yet. Guess it's time to print off that section of the manual.Thanks. Appreciate your time............Iain

The B747-400 doesn't have the possibility to dial the NAV freq's via a radiopanel as in the older aircraft.Only voice communction (+ 118Mhz) can be dialed via de voice radio communication panels.All NAV freq in manual operation (VOR / NDB / ILS) has to be set via de CDU NAV/RAD pages, as these beacons and radiosignals are identified via the FMC /radiodata computers.B. RgdsMichel

Thank you