New Gulf of Mexico RNAV routes have been implemented requiring aircraft to have RNP 10 (as a minimum) or RNP 4. This will allow 50 nautical mile lateral separation between authorized aircraft.
Qualified aircraft can fly these routes with single long range navigation systems (S-LRNS). There are provisions in place for non-RNP 10 (or RNP 4) aircraft. Not all airways within the Gulf of Mexico require RNP10 (or RNP 4) authorization.
Operators are expected to obtain RNP 10 (minimum) or RNP 4 authorization from the appropriate State authority for operations within the GoMex region, however NonRNP 10 aircraft are being accommodated, traffic permitting and with prior coordination with the local ATC units. Aircraft equipped with a Single Long Range Navigation System qualify for RNP 10 for Gulf of Mexico operations only. This is a joint FAA, SENEAM and DGAC Mexico project.
Note: Operators must file the route designators applicable in Monterrey and Merida airspace and those applicable in Houston and Miami Oceanic airspace. For example, the HIGH altitude route segment between Tampico (TAM) and CLONN in Monterrey airspace must be filed as UM575 and the segment between CLONN and Tibby (TBD) in Houston airspace must be filed as M575.
In the Gulf of Mexico, the FAA does not differentiate between HIGH and LOW routes while SENEAM does Flight Planning Requirements
Important Note: RNP 10 is the minimum "navigation specification" for 50 NM lateral separation. RNP 4 is an operator option.
Are RNP 10 policies applicable to all Gulf of Mexico routes and airspace?
NO. RNP 10 policies are not applicable to routes in the Gulf of Mexico that are defined by ICAO standard Navigation Aids (VOR, DME, NDB)
(e.g., UB646 that traverses the Merida, Havana and Miami CTAs. In addition, RNP 10 polices are not applicable to the Gulf of Mexico "Q-routes" in the Houston, Jacksonville and Miami CTAs).
When an aircraft previously authorized RNP 10 loses its RNP 10 capability due to an aircraft system malfunction, should PBN/A1 be deleted from Item 18 of the ICAO flight plan?
YES. In these circumstances, PBN/A1 should be deleted in the ICAO flight plan filed for that flight and in addition, RMK/NONRNP10 should be filed in Item 18 (as the first Remark, if possible).
For a NonRNP 10 aircraft, if there is a long time period between departure and the ETA for the Houston FIR (e.g., 10 hours), does Houston Centre still want notification two hours in advance of departure.
YES. Houston has designed its internal procedures to keep this data on sector by using the UTC date and the aircraft ETA to cross the FIR boundary.
If an aircraft loses RNP 10 capability prior to entry into a Gulf of Mexico Control Area, what action should be taken?
When the degradation occurs, the pilot should notify the controller to amend the aircraft flight plan to show that the aircraft is no longer RNP 10 capable. The pilot should be prepared to tell the controller what part of the flight plan needs to be changed, including the remarks section. When the flight reaches either Miami, Houston, Merida or Monterrey Area Control Centers, the pilot should state "Negative RNP 10" on initial call or when asked by the controller.
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.
ATS - Air Traffic Services
CAR - Caribbean Region
CTA - Control Area
DGAC - Direccion General de Aeronautica Civil (DGAC Mexico)
FIR - Flight Information Region
NACC - ICAO North American, Central American and Caribbean Regional Office (Mexico City)
RNAV 10 - Area Navigation 10
RNP 10 - Required Navigation Performance 10
SAM - South American Region
SENEAM - Serviciós a la Navegacion en el Espacio Aéreo Mexicano (ATS Provider for Mexico)
S-LRNS - Single Long-Range Navigation System