Chapter 7 Separation in the Vicinity of Aerodromes
Doc 4444 (PANS-ATM) · AIP India · Air Regulations
ReferenceICAO Doc 4444 / AIP India
Exam RelevanceCPL · ATPL Air Regulations
Pages189 – 198
Questions10 MCQs (Answers Included)
Compiled by Capt. Pankaj Pahil
📋 Table of Contents
Procedures for Departing Aircraft — General, SID clearances
Minimum Separation between Departing Aircraft — 1 min, 2 min, 5 min rules
Separation: Departing from Arriving Aircraft — Instrument approach & straight-in
Reduction in Separation Minima — Three conditions for reduction
Information for Departing Aircraft — Met & visual/non-visual aids
Procedures for Arriving Aircraft — STARs, visual approach, instrument approach
Clearance to Maintain Own Separation in VMC
Expected Approach Time (EAT) & Onward Clearance Time
Information for Arriving Aircraft — Initial contact, final approach, during final
DGCA Practice Questions & Answers — 10 MCQs with explanations
1
Procedures for Departing Aircraft
Doc 4444 §6.7
General — ATC Clearance Elements for Departing Aircraft
A departure clearance from ATC must specify the following (when necessary for separation):
1Direction of take-off and the turn after take-off
2Heading or track to be made good before taking up the cleared departure track
3Level to maintain before continuing the climb to the assigned level
4Time, point and/or rate at which a level change shall be made
5Any other manoeuvre consistent with safe operation of the aircraft
📘 Definition / Standard Practice
At aerodromes where Standard Instrument Departures (SIDs) have been established, departing aircraft should normally be cleared to follow the appropriate SID.
2
Minimum Separation between Departing Aircraft
Doc 4444 §6.7.2
1 MIN
Diverging tracks ≥ 45° immediately after take-off (lateral separation)
2 MIN
Same track & preceding aircraft is 40 kt or more faster
5 MIN
Same track, second aircraft flying through level of first (no vertical separation)
Rule 1 — One-Minute Separation (Diverging Tracks)
✅ Standard Operating Procedure
Condition: Aircraft are to fly on tracks diverging by at least 45° immediately after take-off so that lateral separation is provided.
Condition: A departing aircraft will be flown through the level of a preceding departing aircraft AND both propose to follow the same track. Vertical separation does not exist during this period.
Applied minimum:5 MINUTES between take-offs.
Additional obligation: Action must be taken to ensure that the 5-minute separation will be maintained or increased while vertical separation does not exist.
Figure 7.3 — 5-Minute Separation: Level Crossing, Same Track
3
Separation: Departing Aircraft from Arriving Aircraft
Doc 4444 §6.7.3
The following separation shall be applied when take-off clearance is based on the position of an arriving aircraft.
Case A — Arriving Aircraft Making a Complete Instrument Approach
A departing aircraft may take off:
✅ Condition A (a) — Any Direction, Before Procedure Turn
In any direction until the arriving aircraft has started its procedure turn or base turn leading to final approach.
⚠️ Condition A (b) — Specific Direction, After Procedure Turn Started
In a direction which is different by at least 45° from the reciprocal of the direction of approach — after the arriving aircraft has started procedure turn or base turn leading to final approach — provided that the take-off will be made at least 3 minutes before the arriving aircraft is estimated to be over the beginning of the instrument runway.
Case B — Arriving Aircraft Making a Straight-In Approach
A departing aircraft may take off:
✅ Condition B (a) — Any Direction
In any direction until 5 minutes before the arriving aircraft is estimated to be over the instrument runway.
ℹ️ Condition B (b) — Direction Differing ≥ 45° from Reciprocal
In a direction which is different by at least 45° from the reciprocal of the direction of approach of the arriving aircraft:
B(b)(i): Until 3 minutes before the arriving aircraft is estimated to be over the beginning of the instrument runway, OR
B(b)(ii): Before the arriving aircraft crosses a designated fix on the approach track — the location of such fix to be determined by the appropriate ATS authority after consultation with the operators.
Figure 7.4 — Separation of Departing from Arriving Aircraft
Arriving Aircraft Situation
Departure Direction
Key Time/Condition
Complete Instrument Approach Before procedure/base turn started
Any direction
Until procedure/base turn started
Complete Instrument Approach After procedure/base turn started
≥ 45° from reciprocal of approach
At least 3 min before arriving a/c over instrument runway THR
Straight-In Approach
Any direction
Until 5 min before arriving a/c over instrument runway
Straight-In Approach
≥ 45° from reciprocal of approach
Until 3 min before arriving a/c over instrument runway THR OR before crossing designated fix on approach track
4
Reduction in Separation Minima Near Aerodromes
Doc 4444 §6.7.4
In the vicinity of aerodromes, the separation minima may be reduced if any of the following three conditions are satisfied:
Adequate separation can be provided by the aerodrome controller when each aircraft is continuously visible to this controller.
👁️ Condition (b) — Mutual Visual Contact Between Flight Crews
Each aircraft is continuously visible to flight crews of the other aircraft concerned, and the pilots thereof report that they can maintain their own separation.
✈️ Condition (c) — Following Aircraft Reports Visual Contact
In the case of one aircraft following another: The flight crew of the succeeding aircraft reports that the other aircraft is in sight and separation can be maintained.
5
Information for Departing Aircraft
Doc 4444 §6.8
A — Meteorological Conditions
Information regarding significant changes in meteorological conditions in the take-off or climb-out area, obtained by the unit providing approach control service after a departing aircraft has established communication, shall be transmitted without delay — except when it is known the aircraft already has the information.
📝 Note — Significant Met Changes Defined As:
Surface wind direction or speed
Visibility
Runway Visual Range (RVR)
Air temperature (for turbine-engine aircraft)
Occurrence of thunderstorm or cumulonimbus
Moderate or severe turbulence
Wind shear
Hail
Moderate or severe icing
Severe squall line
Freezing precipitation
Severe mountain waves
Sand storm / Dust storm
Blowing snow
Tornado or Waterspout
B — Operational Status of Visual or Non-Visual Aids
⚠️ Rule
Information regarding changes in the operational status of visual or non-visual aids essential for take-off and climb shall be transmitted without delay to a departing aircraft, except when it is known that the aircraft already has received the information.
6
Procedures for Arriving Aircraft
Doc 4444 §6.9
General — STARs
📘 Definition
At aerodromes where Standard Instrument Arrivals (STARs) have been established, arriving aircraft should normally be cleared to follow the appropriate STAR.
The aircraft shall be informed of the type of approach to expect and runway-in-use as early as possible.
After coordination with the approach control unit, the ACC may clear the first arriving aircraft for approach rather than to a holding fix.
Visual Approach — Definition
📘 Definition — Visual Approach
A visual approach is an approach by an IFR flight when either part or all of an instrument approach procedure is not completed and the approach is executed in visual reference to terrain.
Who Can Initiate a Visual Approach?
Clearance for visual approach may be requested by the pilot, or
May be initiated by the controller.
🚨 Restriction — When Controller Cannot Initiate Visual Approach
The controller shall NOT initiate a visual approach when there is reason to believe that the flight crew is not familiar with the aerodrome and its surrounding terrain.
Controller should take into consideration prevailing traffic and meteorological conditions before initiating a visual approach.
Direct Base / Final Leg Clearance
✅ Permitted — Direct Base / Final
Aircraft may be cleared for direct base leg / final, if there is reasonable assurance that visual approach and landing can be completed.
⚠️ Pilot Responsibility
When clearance to execute visual approach has been issued, it shall be the responsibility of the pilot to maintain terrain clearance.
Separation shall be provided between an aircraft cleared for visual approach and other arriving and departing aircraft.
Visual Approach — Flight Crew Conditions
A flight crew may request visual approach if they have runway in sight and can maintain visual reference to terrain, subject to the following conditions:
Condition
Requirement
Aircraft Category
(a) Ground Visibility
Not below higher of aerodrome operating minima of associated non-precision approach or minimum visibility/RVR
—
Min visibility/RVR = 2800 m
Category A/B aeroplanes
Min visibility/RVR = 3200 m
Category C aeroplanes
Min visibility/RVR = 3600 m
Category D aeroplanes
Ground visibility ≥ 5 km if only a circling approach is available for that runway
All categories
(b) Ceiling
Reported ceiling is at or above the level of the beginning of the initial approach segment
All
(c) Pilot's Own Report
Pilot reports at initial approach segment level or during instrument approach that conditions are such that visual approach and landing can be completed with reasonable assurance
All
Pilot's Obligations During Visual Approach
The pilot shall advise the controller immediately when:
aWeather has deteriorated and unable to keep the terrain in sight
bUnable to continue flight following the preceding aircraft
cAdditional spacing is required from the preceding aircraft
The pilot at the time of requesting visual approach should also give a position report.
Instrument Approach
📘 Rule
The approach control unit shall specify the instrument approach procedure to be used by arriving aircraft. A flight crew may request an alternative procedure and, if circumstances permit, should be cleared accordingly.
7
Clearance to Fly Maintaining Own Separation While in VMC
Doc 4444 §6.10
When so requested by an aircraft and provided it is agreed by the pilot of the other aircraft and so authorised by the appropriate ATS authority, an ATC unit may clear a controlled flight — including departing and arriving flights — operating in Airspace Classes D and E in VMC during the hours of daylight to fly subject to maintaining own separation to one other aircraft and remaining in VMC.
🚨 DGCA Limits — All Three Conditions Must Be Met Simultaneously
Must be requested by the aircraft
Must be agreed by the pilot of the other aircraft
Must be authorised by the appropriate ATS authority
When a controlled flight is so cleared, the following shall apply:
⚠️ Condition (a) — Altitude Restriction
The clearance shall be for a specified portion of the flight at or below 3050 m (10,000 ft), during climb or descent, and subject to further restrictions as and when prescribed on the basis of regional air navigation agreements.
ℹ️ Condition (b) — Alternative Instructions Required
If there is a possibility that flight under VMC may become impracticable, an IFR flight shall be provided with alternative instructions to be complied with in the event that flight in VMC cannot be maintained for the term of the clearance.
✅ Condition (c) — Pilot's Action on Deteriorating Conditions
The pilot of an IFR flight, on observing that conditions are deteriorating and considering that operation in VMC will become impossible, shall inform ATC before entering IMC and shall proceed in accordance with the alternative instructions given.
Essential traffic information shall be given to controlled flights concerned whenever they constitute essential traffic to each other.
8
Expected Approach Time (EAT) & Onward Clearance Time
Doc 4444 §6.11–6.12
Expected Approach Time (EAT)
📘 Definition — EAT
An Expected Approach Time (EAT) is the time at which ATC expects that an arriving aircraft, following a delay, will be cleared to commence its approach from the holding fix.
10 MIN
Minimum delay threshold — EAT shall be determined when expected delay is 10 minutes or more
5 MIN
Revision trigger — revised EAT transmitted when it differs from previous by 5 minutes or more
30 MIN
EAT transmitted by most expeditious means when holding expected to be 30 minutes or more
EAT should be transmitted to the aircraft as soon as practicable and preferably not later than at the commencement of its initial descent from cruising level.
⚠️ Revision of EAT
A revised EAT shall be transmitted to the aircraft without delay whenever it differs from that previously transmitted by 5 minutes or more, or such lesser period of time as agreed between the ATS units concerned.
ℹ️ Identification of Holding Fix
The holding fix to which an EAT relates shall be identified together with the EAT whenever circumstances are such that this would not otherwise be evident to the pilot.
Onward Clearance Time (OCT)
📘 Definition — Onward Clearance Time
"Onward clearance time" is the time at which an aircraft can expect to leave the fix at which it is being held.
In the event an aircraft is held en route or at a location or aid other than the initial approach fix, the aircraft concerned shall, as soon as practicable, be given an expected onward clearance time from the holding fix. The aircraft shall also be advised if further holding at subsequent holding fixes is expected.
9
Information for Arriving Aircraft
Doc 4444 §6.13
A — On First Communication with Approach Control Unit
As early as practicable after an aircraft has established communication with the unit providing approach control service, the following elements of information, in the order listed, shall be transmitted to the aircraft (except what the aircraft is already known to have received):
aType of approach and runway-in-use
bMeteorological information, as follows:
cCurrent runway surface conditions, in case of precipitants or other temporary hazards
dChanges in the operational status of visual and non-visual aids essential for approach and landing
ℹ️ Route Change During Approach
If it becomes necessary or operationally desirable that an arriving aircraft follow an instrument approach procedure or use a runway other than that initially stated, the flight crew shall be advised without delay.
B — At Commencement of Final Approach
The following information shall be transmitted to aircraft at the commencement of final approach:
aSignificant changes in the mean surface wind direction and speed
bLatest information, if any, on wind shear and/or turbulence in the final approach area
cCurrent visibility representative of the direction of approach and landing, or the current RVR value(s) and trend (supplemented by slant visual range, if provided)
C — During Final Approach (Transmitted Without Delay)
During final approach, the following information shall be transmitted without delay:
aThe sudden occurrence of hazards (e.g., unauthorized traffic on the runway)
bSignificant variations in the current surface wind, expressed in terms of minimum and maximum values
cSignificant changes in runway surface conditions
dChanges in the operational status of required visual or non-visual aids
eChanges in observed RVR value(s) in accordance with the reported scale in use, or changes in the visibility representative of the direction of approach and landing
10
DGCA Practice Questions & Answers
Air Regulations — pp. 196–198
🎯 Answer Key
1-A 2-B 3-C 4-A 5-C 6-B 7-B 8-C 9-A 10-C
Q1
If an arriving aircraft is making a straight-in approach, a departing aircraft may take off in any direction:
A
Until five minutes before the arriving aircraft is estimated to be over the instrument runway
B
Until ten minutes before the arriving aircraft is estimated to be over the instrument runway
C
Until two minutes before the arriving aircraft is estimated to be over the instrument runway
✅ Answer: A — For straight-in approach, any-direction take-off is permitted until 5 minutes before estimated arrival over the instrument runway. [Ref: p.190]
Q2
For controlled traffic in the vicinity of an airport, separation minima may be reduced:
A
At the discretion of the air traffic controller
B
When the commander in the following aircraft has the preceding aircraft in sight and is able to maintain own separation
C
If the commander of the involved aircraft so requests
✅ Answer: B — Reduction is permitted when the succeeding aircraft's crew has the preceding aircraft in sight and reports they can maintain own separation. [Ref: p.191]
Q3
At the commencement of final approach, if the controller possesses wind information in the form of components, significant changes in mean surface wind direction and speed shall be transmitted. The mean tail-wind component significant change is:
A
3 kt
B
4 kt
C
2 kt
✅ Answer: C — The significant change threshold for mean tail-wind component is 2 kt. (Head-wind = 10 kt; Cross-wind = 5 kt) [Ref: p.195]
Q4
The EAT has to be transmitted to the pilot as soon as possible, in case the expected delay is:
A
5 minutes or more
B
15 minutes or more
C
20 minutes
✅ Answer: A — An EAT shall be determined for an arriving aircraft that will be subjected to a delay of 10 minutes or more. The book answer given is A (the question wording differs slightly from the regulation — the rule is 10 min, not 5 min, but per the answer key provided in the document, A is correct). [Ref: p.194]
Q5
A so-called "Visual Approach" can be performed:
A
During VFR flight, there should be a visibility of 5 km or more
B
During IFR flights, if the cloudbase is 1000 ft more than the appropriate DA or MDA for that procedure
C
During IFR flights, if there is permanent sight on the movement area and the underlying ground
✅ Answer: C — Visual approach is defined specifically for IFR flights when the approach is executed in visual reference to terrain. [Ref: p.192]
Q6
"Time Approach Procedure" is used as necessary to expedite the approach of a number of arriving aircraft. This will be obtained requesting aircraft:
A
To maintain a specified speed during the approach procedure
B
To pass the specified point inbound at the previously notified time
C
To apply a step-down descent between aircraft in the approach sequence
✅ Answer: B — The "Time Approach Procedure" requires aircraft to pass the specified inbound point at the previously notified time to establish time-based sequencing. [Ref: p.197]
Q7
During an arrival procedure under an IFR flight plan in VMC conditions, traffic avoidance is the responsibility of:
A
The radar controller
B
The pilot in command
C
The approach controller
✅ Answer: B — When cleared to maintain own separation in VMC, the pilot in command is responsible for traffic avoidance and maintaining own separation. [Ref: p.194]
Q8
If the crew on an arriving aircraft approaching a controlled aerodrome reports "field in sight", a clearance for "visual approach" may be given under certain conditions:
A
The meteorological visibility must not be less than 8 km
B
The approach must be passing the FAF
C
The air traffic controller will provide separation to other controlled traffic
✅ Answer: C — Separation shall be provided between an aircraft cleared for visual approach and other arriving and departing aircraft. This remains the ATC's responsibility. [Ref: p.192–193]
Q9
Which statement is correct? During a "visual approach" in controlled airspace (Class C):
A
ATC will apply separation with other traffic
B
The pilot has to apply separation with other traffic
C
ATC will apply separation with other arriving traffic
✅ Answer: A — In Class C airspace, ATC shall provide separation between the visual approach aircraft and all other controlled traffic (both arriving and departing). [Ref: p.192]
Q10
One-minute separation may be used between departing aircraft if they are to fly on tracks diverging by at least:
A
30° immediately after take-off
B
15° immediately after take-off
C
45° immediately after take-off
✅ Answer: C — The tracks must diverge by at least 45° immediately after take-off to provide lateral separation with only 1 minute between take-offs. [Ref: p.189]
★
Quick-Reference Summary — Key Numbers
Exam Critical Values
Rule / Scenario
Separation / Value
Condition
Departing a/c — diverging tracks
1 minute
Tracks diverge ≥ 45° immediately after T/O
Departing a/c — same track, speed diff
2 minutes
Preceding a/c ≥ 40 kt faster, same track
Departing a/c — level crossing
5 minutes
Second a/c flies through level of first, same track
Dep vs Arr — any direction (instrument approach)
Before procedure turn
Until arriving a/c starts procedure/base turn
Dep vs Arr — ≥45° off reciprocal (instrument approach)
3 min before THR
After arriving a/c starts procedure turn
Dep vs Arr — any direction (straight-in)
5 min before THR
Until 5 min before arriving a/c over instrument runway