Vertical Separation

Question 1

Vertical separation minima for subsonic AC

Answer 1

• Up to FL290; 1000’
• Above FL290; 2000’
• RVSM FL290 - FL410; 1000’

Question 2

Vertical separation minima for supersonic V subsonic or supersonic V supersonic AC

Answer 2

• Up to FL450; 2000’

- Above FL450; 4000’

Question 3

Instruction to change levels

Answer 3

• Specific time, place or rate
• To level previously occupied provided that; Vertical separation already exists or vacating AC proceeding to a level that will maintain vertical separation
• Controller observes vacating AC has left level
• Pilot reported vacating a level

Question 4

Changing levels considerations

Answer 4

• Severe turbulence; Instructions delayed until it is known that vacating AC is at or through another level separated by required minimum
• AC performance; AC may climb/descend at markedly different rates
• ROC/ROD; May be specified to ensure required separation is maintained
• Specified vertical separation; Instructed to maintain during climb/descent if pilots are in direct comms with each other and concur

Question 5

VMC climb and descent

Answer 5

• Class D, E, F and G
• Below FL100
• Daylight hours
• VMC
• Pilot agrees to maintain separation and manoeuvre agreed by other pilot
• Essential TI passed

Question 6

Mode C vertical separation

Answer 6

• Responses are continually monitored to ensure vertical distance is never less than prescribed minimum
• Not applied against A0000
• Applied against verified Mode C provided intentions are known to controller because…
  + Both AC are under same controller’s control
  + Both AC have been coordinated
  + AC are operating IAW established agreements

Question 7

Mode C separation - RCS AC and AC intentions unknown

Answer 7

• IFR Class A-D; 5000’
• VFR Class B/C; 5000’
• Unverified AC in Class A-D; 5000’ minimum
• Class E (unless pilot maintaining own separation);
  No merge

Question 8

Mode C separation - DS AC and AC intentions unknown

Answer 8

• DM increased to 3000’

- Unverified; No merge

Question 9

Mode C verification

Answer 9

• Within 200’ of stated level, once AC identified and Mode A validated
• Pilot instructed to give precise report as AC passes through level when in climb/descent
• May be achieved with assistance from other ATSU
• Mode C assumed verified if associated with deemed validated Mode A
• No requirement to monitor Mode C if not being used for vertical separation

Question 10

Level occupancy

Answer 10

• Maintaining a level; Within 200’
• Vacated a level; 400’ or more in anticipated direction
• Crossed a level; 400’ or more in required direction
• Reached a level; 3 updates, or 15 secs and within 200’