ENR 7.10 Y-Routes

  1. Introduction
    1. The FAA has established a network of area navigation (RNAV) routes to enhance efficiency of air traffic flow and control over the West Atlantic, Gulf of Mexico, the Bahamas, and Puerto Rico. These RNAV routes, charted as “Y” routes, exist largely, but not exclusively, within U.S. “offshore airspace.” Operators may find U.S. offshore airspace labeled as “Atlantic High,” “Atlantic Low,” “Gulf of Mexico High,” etc., on FAA IFR en route charts. In accordance with 14 CFR Part 71, § 71.1, § 71.33, and § 71.71, offshore airspace at and above 18,000 feet MSL is Class A airspace, while that offshore airspace below 18,000 feet MSL is Class E. The FAA normally uses domestic air traffic control procedures, vice oceanic procedures, in offshore airspace. Aircraft flying Y-routes will typically be within signal coverage of U.S. ground navigation facilities and ATC radar. Actual signal reception and radar detection are a function of aircraft altitude. The majority of Y-routes exist only in the upper altitude structure, i.e., Class A offshore airspace.
  2. General Requirements
    1. The Y-routes are designated RNAV 2 with GNSS required. Aircraft flying the Y-routes must be equipped with GNSS and able to meet RNAV 2 performance requirements. RNAV systems relying solely on DME/DME or inertial navigation are not suitable (and therefore not authorized) for use on any Y-route.
    2. Pilots must indicate on their ATC flight plan at least the minimum equipment and capability required for RNAV 2 with GNSS. Item 10 of the flight plan must indicate G and R. Item 18 must indicate PBN/C2.
  3. Operational Requirements
    1. Pilots are expected to fly the route centerline, as defined by the aircraft RNAV system. Pilots must not use strategic lateral offset procedures (SLOP) while on the Y-routes.
    2. Operators must check predicted RAIM availability for the expected duration of their flight on a Y-route. Five (5) minutes is the maximum predicted continuous loss of RAIM allowed for flight on a Y-route.
  4. Pilot Knowledge
    1. Advisory Circular (AC) 90-100, U.S. Terminal and En Route Area Navigation (RNAV) Operations, contains pilot knowledge subject matter that is generally applicable to any RNAV operation. General aviation pilots in particular should use the RNAV subject matter contained in AC 90-100 in preparation for any flight on an RNAV route, including Y-routes.