AIM
4/3/14
4−7−1
Operational Policy/Procedures for the Gulf of Mexico 50 NM Lateral Separation Initiative
Section 7. Operational Policy/Procedures for the Gulf of
Mexico 50 NM Lateral Separation Initiative
4
−
7
−
1. Introduction and Background
a. Introduction.
On 20 October 2011 at 0900
UTC, the Federal Aviation Administration (FAA),
Serviciós a la Navegacion en el Espacio Aéreo
Mexicano (SENEAM) and the Direccion General de
Aeronautica Civil (DGAC) Mexico implemented 50
Nautical Mile (NM) lateral separation between
aircraft authorized Required Navigation Perform-
ance 10 (RNP 10) or RNP 4 operating in the Gulf of
Mexico (GoMex) Oceanic Control Areas (CTA).
Existing Air Traffic Services (ATS) routes and route
operating policies did not change for this implement-
ation.
b. RNP 10 Versus RNAV 10 Terminology.
“RNP
10” has the same meaning and application as “RNAV
10”. The ICAO Performance-based Navigation
(PBN) Manual (ICAO Doc 9613), Volume II, Part B,
Chapter 1 (Implementing RNAV 10, Designated and
Authorized as RNP 10) explains that the term “RNP
10” was in use before the publication of the ICAO
PBN Manual and the manual has “grandfathered in”
its continued use when implementing an “RNAV 10”
navigation specification.
c. Background.
50 NM lateral separation was
first applied between aircraft authorized for RNP 10
operations on the North Pacific Route System in
April 1998. Since that time, 50 NM lateral separation
has been expanded throughout the Pacific Flight
Information Regions (FIRs) and is currently applied
in other airspaces, including, starting in June 2008,
the West Atlantic Route System. GoMex 50 NM
lateral separation implementation will apply the
experience gained in those operations.
d. Project Objectives.
The project objectives
were to:
1.
Reduce lateral separation to 50 NM between
aircraft authorized RNP 10 or RNP 4.
2.
Leave existing ATS routes and operating
policies in place.
3.
Have approximately 90% of flights conduc-
ted by operators/aircraft over the Gulf of Mexico
authorized for RNP 10 or RNP 4 operations by the
appropriate State authority.
4.
Accommodate the operation of the small
percentage of flights not authorized RNP 10.
5.
Establish a policy that aircraft equipped with
a Single Long-Range Navigation System (S-LRNS)
can qualify for RNP 10 operations in the Gulf of
Mexico in accordance with the ICAO PBN Manual
and the appropriate FAA and DGAC documents. (See
e. Control Areas (CTA) Affected.
50 NM lateral
separation is implemented in the following CTAs/
FIRs/Upper Control Areas (UTA).
1
The Houston Oceanic CTA/FIR and the
Gulf of Mexico portion of the Miami Oceanic
CTA/FIR.
(a)
The Monterrey CTA and Merida High
CTA within the Mexico FIR/UTA
f. Policy and Procedures Coordination with
SENEAM and the DGAC.
The policies and
procedures were coordinated with SENEAM and the
Mexico DGAC. They are applied in the GoMex
CTA’s where the FAA and SENEAM provide Air
Traffic Control.
4
−
7
−
2. Gulf of Mexico 50 NM Lateral
Separation Initiative Web Page: Policy,
Procedures and Guidance for Operators
and Regulators
Information on plans, policies and procedures for 50
NM lateral separation is posted on the “Gulf of
Mexico 50 NM Lateral Separation Web Page”:
http://www.faa.gov/about/office_org/headquar-
ters_offices/ato/service_units/enroute/oceanic/gome
x/
The web page contains detailed guidance on operator
and aircraft authorization for RNP 10 or RNP 4 and
includes Job Aids with FAA and ICAO document
references.
4
−
7
−
3. Lateral Separation Minima Applied
a.
50 NM lateral separation is applied in the
GoMex CTA’s between aircraft authorized RNP 10 or
RNP 4 at all altitudes above the floor of controlled
airspace.