Separation and Wake Turbulence for all Oral Boards

Question 1

What conditions may a controller impart on a level change instruction?

Answer 1

Aircraft may be instructed to change level at a specified time, place or rate.

Question 2

What are the conditions for climb or descent in VMC?

Answer 2

When climbing/descending in VMC when;

• Essential Traffic Information is passed
• the pilot agrees to maintain his own separation from other a/c and the maneuver is agreed by the pilot of the other a/c;
• it is during the hours of daylight;
• the aircraft is flying in VMC;
• In Class D, E, F* and G* (*UK difference) airspace at or below FL100

Question 3

What does essential Traffic information contain?

Answer 3

• Direction of flight
• Type of conflicting aircraft.
• Cruising level of conflicting ACFT & ETA for Reporting Point. Or for aircraft passing through levels, ETA Reporting Point nearest where aircraft will cross levels.
• Any alternative clearance.

“Essential traffic information, a (direction of flight) (a/c type), maintaining/climbing to/descending to (level) estimating (position) at (time), (any alternative clearance)”

Question 4

Under what conditions may an a/c be instructed to climb/descend to a level previously occupied by another a/c?

Answer 4

An aircraft may be instructed to climb or descend to a level previously occupied by another aircraft provided that:

• Vertical separation already exists. or;
• Vacating aircraft is proceeding to a level which will maintain vertical separation, & either:

1. Controller observes vacating aircraft has left the level, or
2. Pilot has reported vacating the level.

Question 5

What is radar separation?

Answer 5

Horizontal Separation based on radar exists when the distance between the centres of the radar returns does not represent less than the prescribed minimum, provided that the returns do not touch or overlap.

Question 6

When may standard separtation be reduced in the vicinity of an aerodrome?

Answer 6

Also in the vicinity of an aerodrome as per ICAO, when:

• ADC continuously sees all the aircraft, and can provide adequate separation
• Aircraft see each other and agree to maintain separation (– good in circuit at night if IFR.)
• Following aircraft sees the one in front and agrees to maintain separation.

Question 7

When may standard separation be reduced?

Answer 7

• May be reduced when authorised by the CAA and published in MATS Pt2.
• Reduced separation in the vicinity of the aerodrome
• Search and Rescue escorts- Standard Separation maybe reduced when escorting in an emergency
• When climbing/descending in VMC

Question 8

What shall you do in the event of a loss of separation?

Answer 8

• Use every means to obtain the required minimum with the least possible delay
• When considered practicable pass traffic info (when using RADAR) otherwise pass Essential Traffic Info.

Separate then inform!!!

Question 9

How would you pass Essential Traffic Information as per CAP413?

Answer 9

“Essential traffic information, a (direction of flight) (a/c type), maintaining/climbing to/descending to (level) estimating (position) at (time), (any alternative clearance)”

Question 10

How are levels assessed using Mode C?

Answer 10

1. An aircraft may be considered to be at an assigned level provided that the Mode C readout indicates 200 feet or less from that level;
2. An aircraft which is known to have been instructed to climb or descend may be considered to have left a level when the Mode C readout indicates a change of 400 feet or more from that level and is continuing in the anticipated direction;
3. An aircraft climbing or descending may be considered to have passed through a level when the Mode C readout indicates that the level has been passed by 400 feet or more and continuing in the required direction;
4. An aircraft may be considered to have reached an assigned level when three successive Mode C readouts indicate 200 feet or less from that level.

Question 11

Why do we apply longitudinal separation?

Answer 11

Longitudinal separation shall be applied so that the spacing between the estimated positions of the aircraft being separated is never less than the prescribed minima

Question 12

How can Longitudinal Separation be applied?

Answer 12

Distance or time;

• Depart at a specified time
• To lose time to arrive over a geographical point at a specified time
• To hold over a geographical location until a specified time

Question 13

What are the times for longitudinal separation of departing a/c and what are the conditions? (MATS 1)

Answer 13

1 min- If the a/c are flying on different tracks separated by at least 45°. Minima may be reduced if using lateral runways which do not cross, procedure must be approved and lateral separation must be effected immediately after take off.

2 min- For tracks not separated by 45° provided that the preceding a/c is 40kts or more faster and neither aircraft is cleared to execute a manoeuvre that would decrease the 2 min separation between them.

5 min- Provided that the preceding aircraft has filed a true airspeed of 20kts or more faster than the following aircraft.

5 min- Provided that 5 minutes separation is maintained up to a reporting point, within or adjacent to a control zone or terminal control area and the a/c will be subesequently separated either;

1) Vertically
2) by Tracks which diverte by 30° or more; or
3) by radar
* Only to be used at locations approved by CAA*

10 min

Question 14

What are the distance based longitudinal separations for a/c on recipricol tracks in the UK?

Answer 14

Recipricol Tracks

40nm unless both a/c have been established as having crossed each other and are at least 10nm apart, if within 100nm of a DME/TACAN this may be further reduced to 5nm

Question 15

Why do we apply Lateral Separation?

Answer 15

so that the distance between those portions of the intended routes for which aircraft are to be laterally separated is never less than an established distance to account for navigational inaccuracies plus a specified buffer.

• This buffer shall be determined by the appropriate authority and included in the lateral separation minima as an integral part thereof

If Nav equipment fails or capability detoriates then Pilot must inform ATC

Question 16

How is Lateral Separation established?

Answer 16

By requiring aircraft to operate;

– On different routes, or

– In different geographical locations as determined by:

• Visual observation, or
• By use of navigation aids, or
• By use of area navigation (RNAV) equipment

Question 17

Whom do we separate in Class A airspace and who is allowed in it?

Answer 17

IFR only

All flights separated

Question 18

Whom do we allow in Class C airspace and what are the separations?

Answer 18

IFR and VFR

IFR separated from IFR and VFR

VFR separated from IFR, TI given on other VFR

Question 19

Whom do we allow in Class D airspace and what are the separations?

Answer 19

IFR/SVFR and VFR

IFR separated from IFR, TI on VFR

VFR given TI on IFR and other VFR

SVFR treated as IFR for all intents and purposes

Question 20

Whom do we allow in Class E airspace and what are the separations?

Answer 20

IFR and VFR

IFR separated from other IFR, given TI on participating and non participating VFR traffic

Participating VFR traffic given TI on IFR and other participating and non partcipating VFR flights, BS

Question 21

What are the UK definitions of same, recipricol and crossing tracks?

Answer 21

• ‘Same track’ when the track of one aircraft is separated from the track of the other by less than 45°;
• ‘Reciprocal track’ when the track of one aircraft is separated from the reciprocal of the other by less than 45°;
• ‘Crossing track’ intersecting tracks which are not classed as ‘same’ or ‘reciprocal’

Question 22

What is geographical separation in the UK?

Answer 22

• Positive position reports over different geographical locations - specified as being separated (MATS Pt2).

Question 23

What are the UK lateral separations using a VOR and co-located/associated DME/TACAN?

Answer 23

Both a/c diverging

• Must be on tracks diverging by more than 20° and one of the a/c must be at least 15miles from the VOR/DME/TACAN
• If diverging by 45° or more than they are separated straight away.

Both a/c converging

-Tracks must have a difference of at least 20° and one of the a/c must be at least 30miles from the VOR/DME/TACAN

When on a/c inbound other is outbound

-Tracks must have a difference of at least 20° and the inbound a/c must be at least 30nm from the VOR or the outbound a/c must be 20nm from the VOR/DME/TACAN.

Question 24

When using a bearing from an NDB what are the UK track lateral separations?

Answer 24

When both a/c diverging

-Tracks must be separated by 30° or more and one aircraft must be the time equivalent of 15miles or 4 mins from the NDB, whichever is greater.

Question 25

What are the UK wake turbulence categories?

Answer 25

Super- Over 136,000kg

Heavy- 136,000Kg or more

Medium;

Uppermedium- 136,000-104,000kg

Lower medium- 104,000kg-40,000kg

Small- 40,000-17,000kg

Light- 17,000kg or less.

Question 26

What wake turbulence category is used on FPL’s

Answer 26

ICAO ones not UK, to comply with PANS-ATM

Question 27

What are the time based longitudinal separations for aircraft flying on the same track and same level according to MATS 1?

Answer 27

2 min Provided 2 min departure sep has been applied

3 min When specifically authorised by the CAA and both aircraft are;

1) equipped with functioning transponders and;
2) both aircraft are continuously monitored by RADAR and the actual distance between them is never less than 20nm.

5 min Provided preceding aircraft has filed an air speed of 20kts or more faster than the following aircraft.

5 min when specifically authorised by the CAA provided both aircraft are;

1) equipped with functioning transponders and;
2) monitored by RADAR and the actual distance between them is never less than 30nm.

10 min otherwise

Question 28

What are the time based longitudinal separations for aircraft climbing or descending through levels when flying on the same track according to MATS 1?

Answer 28

5 min Provided that the level change is commenced within 10 mins of the time the aircraft has reported over the same exact reporting point.

10 min

Question 29

What are the time based longitudinal separations for aircraft Crossing tracks according to MATS 1?

Answer 29

10 min

Question 30

What are the time based longitudinal separations for aircraft flying on recipricol tracks according to MATS 1?

Answer 30

10 min before and after estimated passing time

Vertical separation shall be provided for at least 10 mins both prior to and after the estimated time of passing unless it has been confirmed that the aircraft have actually passed each other by;

1) ATS surveillance system information
2) Visual reports from both pilots (day only)
3) Aircraft reports over the same ERP provided vertical separation is maintained for sufficient time to take into account navigational errors

Question 31

What are the wake turbulence distances for a/c on final approach?

Answer 31

Question 33

What are the types of Horizontal separation?

Answer 33

• Longitudinal
• Lateral
• RADAR

Question 34

What is an ERP?

Answer 34

Exact reporting Point

Established;

• Overhead a VOR or NDB
• Intersection of 2 VOR radials
• Intersection of a VOR radial and a bearing from an NDB
• Range and radial from a co-located or associated VOR/DME

Question 35

What are the distance based longitudinal separations for a/c on the same track when climbing and descending in the UK?

Answer 35

Climbing or descending on the same track

15nm at the time that the levels are crossed

Question 36

What are the distance based longitudinal separations for a/c on the same track and level in the UK?

Answer 36

Same level;

15nm When the leading a/c is 20kts TAS or more faster and both a/c are within 100nm of a DME/TACAN

20nm When the leading a/c is 20kts TAS or more faster

20nm when both a/c are within 100nm of a DME/TACAN

25nm otherwise

Question 37

What is the time based longitudinal separation we apply between an aircraft departing and those already en-route?

Answer 37

10mins

5 mins provided

• En-route a/c is 20kt or more faster,
• En-route a/c has reported over an ERP where departing traffic joins the route and
• Departing traffic instructed to arrive at that point 5 mins behind en-route aircraft.

Question 38

When using DME’s to establish separation what is the minimum range the aircraft must be from the DME?

Answer 38

15nm,

within this range slant error makes the reading too unreliable therefore any aircraft within 15nm must be treated as if it is 15nm away.

For example if Aircraft A is outbound from a DME passing 17 miles what range can a following aircraft be instructed to climb through the first ones level? The first a/c must be 30nm because even though only 15nm is needed between them the second aircraft will be treated as if it is 15nm until it actually reaches there, therefore the first aircraft must be 30nm for the requisite 15nm to exist.

Question 39

What are the wake turbulence separations for a/c heading in opposite directions?

Answer 39

L/M following H= 2 mins

L following M= 2 mins

L/M following J= 3 mins

• Departing on the opposite runway heading.
• Is landing in the opposite direction on the same runway. or;
• Is landing in the opposite direction on a parallel runway separated by less than 760m

Question 40

What are the wake turbulence separations for arriving aircraft when using a displaced threshold?

Answer 40

Arr L/S/M behind a H dep= 2mins

Arr L behind M/S dep= 2mins

Arr H behind J dep= 2mins

Arr L/S/M behind J dep= 3 mins

or

Dep L/S/M behind a H arr= 2mins

Dep L behind a S/M arr= 2mins

Dep H behind a J arr= 2mins

Dep L/S/M behind J arr= 3mins

If projected flight paths are expected to cross.

Question 41

What are the wake turbulence separations for Departing A/C when intermediate?

Answer 41

H behind J= 3 mins

L/M behind H= 3 mins

L behind S/M= 3 mins

L, S & M behind J= 4 mins

H behind H= 4nm or time equivalent

Just add 1 min to the normal separations

Question 43

What are the wake turbulence separations for Departing A/C when not intermediate?

Answer 43

H behind J= 2 mins

L/M behind H= 2 mins

L behind S/M= 2mins

L, S & M behind J= 3 mins

H behind H= 4nm or time equivalent

Question 44

What wake turbulence separations do we apply for an a/c on a touch and go behind a departing a/c?

Answer 44

The same as an intermediate departure

H behind J= 3 mins

L/M behind H= 3 mins

L behind S/M= 3 mins

L, S & M behind J= 4 mins

H behind H= 4nm or time equivalent

Just add 1 min to the normal separations

Question 45

What wake turbulence is applied for aircraft departing or arriving behind another on a low approach and go-around?

Answer 45

For wake turbulence separation purposes, aircraft carrying out a touch-and-go or a low approach shall be considered as making a departure from an intermediate point on the runway

Question 46

For departing wake turbulence what do we treat Smalls as?

Answer 46

A medium a/c

so a small departing behind an uppermedium requires no wake turbulence separation.

Question 47

What is the phraseology for wake turbulence for those following a heavier aircraft?

Answer 47

Caution wake turbulence, recommended distance is xxx miles.

Question 48

What is the phraseology for wake turbulence for a/c waiting to depart?

Answer 48

Hold position. x mins delay due wake turbulence.