Australian Separation Standards
Yep- we have them. I thought everyone did??
Australian MATS:
Runway Separation Standards -
Take-off
10-55-410
Behind a preceding departing aircraft
Apply the 'take-off behind a preceding departing aircraft' standard to fixed wing aircraft, provided that you do not permit a departing aircraft to commence take-off unless the preceding departing aircraft:
a. has crossed the up-wind end of the runway-in-use; or
b. has commenced a turn; or
c. is airborne and has reached a point at least 1800 M (6000 FT) ahead of the following aircraft, provided the runway is longer than 1800 M (6000 FT) and the distance can be readily determined; or
d. is airborne and has reached a point at least 600 M (2000 FT) ahead of the following aircraft provided the :
1. preceding aircraft has an MTOW of 7000 KG or less
2. following aircraft has an MTOW of less than 2000 KG; and
3. following aircraft is slower than the preceding aircraft; or
e. is airborne and has reached a point at least 600 M (2000 FT) ahead of the following aircraft, provided both aircraft have an MTOW of less than 2000 KG.
Given my example of the Lear Vs C182 it's certainly possible, if the situation is reversed ie C182 on final with the Lear to go, that, in the event of the C182 going around, there would be a procedural separation standard available. Given the performance of the Lear there's a good chance it would be through A040 quickly enough to give you A030 for the C182. In a radar environment the speed differential would probably give you your required 3nm separation.
Once again the controller's judgement determines the timing of when the departing aircraft is cleared for take-off. This is where appropriate training and experience is all part of not boxing yourself into a corner with no way out. After all there's normally an easy way and a hard way to do it. Hopefully you can have a long and happy career by doing it the easy way.