9. ADC Reduced Seperations

Question 1

When may standard separation minima be reduced in the vicinity of an Aerodrome?

Answer 1

• Adequate separation can be provided by the aerodrome controller when each aircraft is continuously visible to this controller
• 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
• 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

Question 2

REDUCED RUNWAY SEPARATION MINIMA BETWEEN AIRCRAFT USING THE SAME RUNWAY.

Answer 2

Provided that an appropriate, documented safety
assessment has shown that an acceptable level of
safety can be met, lower minima than those in 7.9.2
& 7.10.1 (turn, vacate or upwind) may be prescribed
by the appropriate ATS authority, after consultation
with the operators.

The safety assessment shall be carried out for
each runway for which the reduced minima are
intended, taking into account factors such as:

• runway length;
  • aerodrome layout; and
  • types / categories of aircraft involved.

Question 3

Where should Runway reduced Separation minima be published and what should controllers do?

Answer 3

• AIP
• Local Air Traffic Control Instructions (MATs Part 2)

Controllers shall be provided with appropriate and adequate training in the use of the procedures.

Question 4

What are the conditions that allow use of the Reduced Runway Separation Minima? (9)

Answer 4

• Daylight only (30mins after local sunrise until 30mins before local sunset;
• Wake Turbulence separation shall be applied;
• Visibility at least 5K & ceiling not below 1000’;
• Tailwind component must not exceed 5kts;
• Landmarks/Visual references - to allow ATCOs to assess distances;
• SMGCS(if used) must be approved (safety case approved);
• Min separation continues to exist immediately after the departure of 2nd aircraft;
• Traffic info must be given to 2nd aircraft;
• Good Braking Action - no contaminants (snow, ice, water etc.)

Question 5

What are the classifications of Aircraft for Reduced Runway Separation Minima?

Answer 5

Category 1 - Single-engine prop AC - MTOM (c) <2000kg or
Category 2 - Single-engine prop AC - MTOM (c) >2000kg - <7000kg;
- Twin-engine prop AC - MTOM (c) <7000kg.
Category 3 - All Other Aircraft

MTOM (c) - Maximum Certificated Take-Off Mass
(c) - Certified

Question 6

When can Reduiced Runway Seperation Minima not be used?

Answer 6

Shall not apply between a departing aircraft and a preceding landing aircraft

Question 7

Reduced runway separation minima which may
be applied at an aerodrome shall be determined
for each separate runway.
The separation to be applied shall in no case be
less than the following minima:
LANDING AIRCRAFT

Answer 7

A succeeding landing Category 1 aircraft may cross the runway threshold when the preceding (before) aircraft is a Category 1 or 2 aircraft which either:

i. has landed and passed a point at least 600m from the threshold of the runway, is in motion and will vacate the runway without back-tracking; or
ii. is airborne and has passed a point at least
600m from the threshold of the runway;

A succeeding landing Category 2 aircraft may cross the runway threshold when the preceding aircraft is a Category 1 or 2 aircraft which either:

i. has landed and has passed a point at least 1500m from the threshold of the runway, is in motion and will vacate the runway without back-tracking; or
ii. is airborne and has passed a point at least 1500m from the threshold of the runway;

A succeeding landing aircraft may cross the runway threshold when a preceding Category 3 aircraft:

i. has landed and has passed a point at least 2400m from the threshold of the runway, is in motion and will vacate the runway without back-tracking; or
ii. is airborne and has passed a point at least 2400m from the threshold of the runway;

Question 8

Reduced runway separation minima which may
be applied at an aerodrome shall be determined
for each separate runway.
The separation to be applied shall in no case be
less than the following minima:
DEPARTING AIRCRAFT

Answer 8

1. A Category 1 aircraft may be cleared for
   take-off when the preceding departing
   aircraft is a Category 1 or 2 aircraft which is
   airborne and has passed a point at least
   600m from the position of the succeeding
   aircraft;
2. A Category 2 aircraft may be cleared for
   take-off when the preceding departing
   aircraft is a Category 1 or 2 aircraft which is
   airborne and has passed a point at least
   1500m from the position of the succeeding
   aircraft; and
3. An aircraft may be cleared for take-off when
   a preceding departing Category 3 aircraft is
   airborne and has passed a point at least
   2400m from the position of the succeeding
   aircraft.

Consideration should be given to increased separation between high performance single-engine aircraft and preceding Category 1 or 2 aircraft.