[Bounder!]

My apologies, seems the menu options/structure has changed since last year (the last time I checked). I just loaded up a single player campaign and found in order to ask for takeoff clearance you now need to:

(1) press tab (this brings up the command list)
(2) press 7 (option "ground control")
(3) press 7 (option "request takeoff clearing")
note: pressing "0" takes you back a step in the command list.

So, pressing "tab" brings up the main command menu that gives a number of possibilities (see below). Pick a number from 1-9 from the main menu, in certain cases it will take you to a sub-menu with further options. Give it a go and let us know how it works. If in doubt try the different command list options yourself, try and follow the menu and explore what options are available e.g. when requesting takeoff / landing clearance you will want to find the option for ground control etc. I'm not sure all the options are working currently in-game and as far as I know from reading the forum it's hopefully something that will get fixed. I haven't played an offline campaign in ages - the last time I did the 'request take off clearance' option seemed to work and was useful for getting the AI controlled planes moving (and out of your way so you can take off). Anyway... just for reference, the list below is the command menu structure I get in the stock RAF Campaign. In bold are the main options on the main menu (root menu) after pressing tab; sub-menu command options available are in italics.

1 Recipient
2 Help Me
3 Maintain Radio Silence
4 Mission
5 Air Targets
........1 Report Contacts
........2 Target From Task
........3 All
........4 Fighters
........5 Bombers
........6 My Target Type (by viewpoint)
........7 My Target (by viewpoint)
........8 Defend
..................1 Mission Target
..................2 All
..................3 Fighters
..................4 Bombers
..................5 My Target Type (by viewpoint)
..................6 My Target (by viewpoint)
..................0 Back
........9 Attack Type
..................1 Head On
..................2 Zoom and Boom
..................0 Back
........0 Back
6 Navigation
........1 Formation
..................1 Echelon Right
..................2 Echelon Left
..................3 Vic
..................4 Finger Four
..................5 Diamond
..................6 Line Abreast
..................7 Line Astern
..................8 Spacing
....................................1 Close
....................................2 Near
....................................3 Middle
....................................4 Far
....................................0 Back
..................0 Back
........2 Disengage
........3 Rejoin
........4 Next Point
........5 Previous Point
........6 Loiter Here
........7 Proceed To Task
........8 Return To Base
........9 Land Immediately
........0 Back
7 Ground Control
........1 Vector To Home Base
........2 Vector To Nearest Base
........3 Vector To Nearest Target
........4 Vector To Nearest Threat
........5 Request Assistance
........6 Request For Landing
........7 Request Take Off Clearing
........8 Declare Emergency
........0 Back
8 Radar
........1 Report On Station
........2 Vector To Target
........3 Vector To Nearest Threat
........4 Vector To Home Base
........5 Vector in Sight
........6 Cannot See Target
........7 Target Friendly
........8 Target Hostile
........9 Request Assistance
........0 Back
9 Crew
........1 Maintain Silence
........2 Hold Fire
........3 Report Status
........4 Bail Out
........5 Crew
.................1 Hand Over Control
.................2 Landing Gear Control
.................3 Flaps Control
.................4 Report Airspeed
.................5 Report Altitude
.................0 Back
........6 Crew
.................1 Report Airspeed
.................2 Report Altitude
.................3 Vector To Target
.................4 Vector To Base
.................5 Vector To Nearest Base
.................0 Back
........7 Crew
.................1 Hand Over Control
.................2 Make Left
.................3 Make Right
.................0 Back
........8 Crew
.................1 Break Left
.................2 Break Right
.................0 Back
........0 Back
0 Back