Section 7. Airport Arrival Rate
(AAR)
10-7-1. PURPOSE
To establish standards for
determining the airport arrival rate (AAR).
10-7-2. POLICY
Airport runways are assets of the
National Airspace System (NAS). System-wide standards
for AARs enable the Air Traffic Organization (ATO) to
manage these assets in the most efficient manner.
10-7-3. DEFINITIONS
a. AAR: A dynamic parameter
specifying the number of arrival aircraft that an
airport, in conjunction with terminal airspace, can
accept under specific conditions throughout any
consecutive sixty (60) minute period.
b. Airport Primary Runway
Configuration: An airport runway configuration which
handles three (3) percent or more of the annual
operations.
10-7-4. RESPONSIBILITIES
a. System Operations
Services is responsible for the development,
establishment, and implementation of AARs at select
airports in the NAS.
b. The Managers, Tactical
Operations (MTOs) in collaboration with Terminal
Facility Managers must:
1. Identify the airport
primary runway configurations for airport(s)
identified by System Operations Services.
2. Establish optimal AARs
for airport(s) using the method detailed in para
10-7-5, Calculating AARs.
3. Review and validate the
airport primary runway configurations and associated
AARs in February of each year, or at more frequent
intervals if required.
NOTE-
In the event consensus cannot be reached between
facilities, the MTO will make the final determination.
c. MTOs must ensure that the
data is entered in the National Traffic Management Log
(NTML) under the runway template.
d. Consistent with para
10-1-6, Selecting Active Runways, Terminal Facility
Managers must ensure efficiency at airport(s) within
their jurisdiction consistent with the goals outlined
in the Administrator's Flight Plan.
10-7-5. CALCULATING
AARs
a. Calculate optimal AAR
values for each airport runway configuration for the
following weather conditions:
1. Visual Meteorological
Conditions (VMC)- Weather allows vectoring for a
visual approach.
2. Marginal VMC- Weather
does not allow vectoring for a visual approach, but
visual separation on final is possible.
3. Instrument Meteorological
Conditions (IMC)- Visual approaches and visual
separation on final are not possible.
4. Low IMC- Weather dictates
Category II or III operations, or 2.5 miles-in-trail
(MIT) on final is not available.
b. Calculate the maximum
runway arrival capacity for each runway using the
following methodology:
1. Determine the average
ground speed crossing the runway threshold and the
spacing interval required between successive arrivals.
2. Divide the ground speed
by the spacing interval or use TBL 10-7-1, Maximum
Runway Capacity, to determine the maximum runway
arrival capacity.
FORMULA:
Ground Speed in knots at threshold / Spacing Interval
at runway threshold in miles
NOTE-
When the maximum runway arrival capacity is a
fraction, round down to the next whole number.
EXAMPLE-
1. 130 / 3.25 = 40 Runway capacity = 40
2. 125 / 3.0 = 41.66 Runway capacity = 41
TBL 10-7-1
Maximum Runway Capacity
Threshold Ground Speed
|
Miles Between Aircraft
|
2.5 |
3 |
3.5 |
4 |
4.5 |
5 |
6 |
7 |
8 |
9 |
10 |
130 Knots |
52 |
43 |
37 |
32 |
28 |
26 |
21 |
18 |
16 |
14 |
13 |
140 Knots |
56 |
46 |
40 |
35 |
31 |
28 |
23 |
20 |
17 |
15 |
14 |
c. Identify any conditions
that may reduce the maximum runway arrival capacity.
These factors include, but are not limited to:
1. Intersecting
arrival/departure runways.
2. Distance between arrival
runways.
3. Dual purpose runways
(shared arrivals and departures).
4. Land and Hold Short
utilization.
5. Availability of high
speed taxiways.
6. Airspace
limitations/constraints.
7. Procedural limitations
(missed approach protection, noise abatement, etc.).
8. Taxiway layouts.
9. Meteorological
conditions.
d. Determine the adjusted
runway arrival capacity by adjusting the maximum
runway capacities using the factors in subpara c for
each runway used in an airport configuration. Total
the adjusted runway arrival capacities for all runways
used in an airport configuration to determine the
optimal AAR for that airport runway configuration.
10-7-6. OPERATIONAL AARs
a. When using an airport
primary runway configuration, the associated optimal
AAR must be utilized. The MTOs must ensure that the
responsible person at the Aviation System Performance
Metrics (ASPM) airports document the runway
information in the NTML.
b. Real-time factors may
dictate dynamic adjustments to the optimal AAR. These
factors include, but are not limited to:
1. Aircraft type/fleet mix.
2. Runway conditions.
3. Runway/taxiway
construction.
4. Equipment outages.
5. TRACON constraints.
These factors will be included in
the facility log. The MTOs must ensure that the
responsible person at the ASPM airports document the
information in the NTML.
c. A dynamic adjustment to
the AAR is subject to the review and approval of the
Director of System Operations, ATCSCC.
d. Non-primary
configurations at ASPM airports must be entered in the
NTML as “Other,” and free-text used to describe the
configuration and associated AAR. |