AIM
4/20/23
4
−
7
−
2
Operational Policy/Procedures for the Gulf of Mexico 50 NM Lateral Separation Initiative
the aircraft and operator qualification criteria for RNP 10 or RNP 4 authorizations. FAA personnel at flight
standards district offices (FSDO) and certificate management offices (CMO) will use the guidance contained
in AC 90
−
105 to evaluate an operator’s application for RNP 10 or RNP 4 authorization. Authorization to conduct
RNP operations in oceanic airspace is provided to all U.S. operators through issuance of Operations
Specification (OpSpec), Management Specification (MSpec), or Letter of Authorization (LOA) B036, as
applicable to the nature of the operation; for example, Part 121, Part 91, etc. Operators may wish to review FAA
Order 8900.1, Flight Standards Information Management System, volume 3, chapter 18, section 4, to understand
the specific criteria for issuing OpSpec, MSpec, and/or LOA B036.
b.
The operator’s RNP 10 or RNP 4 authorization should include any equipment requirements and RNP 10
time limits (if operating solely inertial
−
based navigation systems), which must be observed when conducting
RNP operations. RNP 4 requires tighter navigation and track maintenance accuracy than RNP 10.
4
−
7
−
4. Authority for Operations with a Single Long
−
Range Navigation System
Operators may be authorized to take advantage of 50 NM lateral separation in the Gulf of Mexico CTAs when
equipped with only a single long
−
range navigation system. RNP 10 with a single long
−
range navigation system
is authorized via OpSpec, MSpec, or LOA B054. Operators should contact their FSDO or CMO to obtain
information on the specific requirements for obtaining B054. Volume 3, chapter 18, section 4 of FAA Order
8900.1 provides the qualification criteria to be used by FAA aviation safety inspectors in issuing B054.
4
−
7
−
5. Flight Plan Requirements
a.
In order for an operator with RNP 10 or RNP 4 authorization to obtain 50 NM lateral separation in the Gulf
of Mexico CTAs, and therefore obtain preferred routing available to RNP authorized aircraft, the international
flight plan form (FAA 7233
−
4) must be annotated as follows:
1.
Item 10a (Equipment) must include the letter “R.”
2.
Item 18 must include either “PBN/A1” for RNP 10 authorization or “PBN/L1” for RNP 4 authorization.
b.
Indication of RNP 4 authorization implies the aircraft and pilots are also authorized RNP 10.
c.
Chapter 5, Section 1, of this manual includes information on all flight plan codes. RNP 10 has the same
meaning and application as RNAV 10. They share the same code.
4
−
7
−
6. Contingency Procedures
Pilots operating under reduced lateral separation must be particularly familiar with, and prepared to rapidly
implement, the standard contingency procedures specifically written for operations when outside ATC
surveillance and direct VHF communications (for example, the oceanic environment). Specific procedures have
been developed for weather deviations. Operators should ensure all flight crews operating in this type of
environment have been provided the standard contingency procedures in a readily accessible format. The margin
for error when operating at reduced separation mandates correct and expeditious application of the standard
contingency procedures. These internationally accepted procedures are published in ICAO Document 4444,
chapter 15. The procedures are also reprinted in the U.S. Aeronautical Information Publication (AIP), En Route
(ENR) Section 7.3, Special Procedures for In
−
flight Contingencies in Oceanic Airspace; and AC 91
−
70.