Separation Standards and Control Procedures
The separation toolbox
Vertical, horizontal (lateral and longitudinal), radar and visual. In RVSM airspace (FL290-FL410 in UAE airspace) the vertical minimum between RVSM-approved aircraft is 1000 ft; above FL410 and below FL290 it is 2000 ft. Non-RVSM aircraft in RVSM airspace need the greater minimum - a classic trick question.
Longitudinal time separation is commonly 15 minutes on the same track, reducible to 10 minutes where navigation performance and Mach technique are assured. Lateral separation comes from prescribed routes, geographical separation or distinct significant points. Radar separation is typically 5 NM en route, 3 NM in terminal airspace and 2.5 NM for successive aircraft established on the same final approach. Wake turbulence minima are added on top and depend on the leader/follower categories (Light, Medium, Heavy, Super).
Traps
Applying 3 NM where only 5 NM is authorised; assuming separation ends at the boundary rather than at transfer of control; treating essential traffic information as separation (it is not); assuming 'runway vacated' equals 'separated' for successive departures.
Worked example
Aircraft A and B on the same track, B ten minutes behind, both at 480 kt groundspeed. Distance = 480 x 10/60 = 80 NM. If the required minimum is 15 minutes, the gap becomes 120 NM. Speed control, level allocation or vectors must close the deficit before the minimum is eroded.
Rule of thumb
State the method first (vertical, lateral, longitudinal, radar), then the number, then any wake addition. Controllers who name the method rarely fall for the wrong-figure distractors.