A recent legal interpretation of FAR 91.130, “Operations in Class C airspace,” by the FAA chief counsel answers a question about the two-way radio communications requirement for an aircraft departing a satellite airport in Class C airspace. (As a reminder, a satellite airport is any airport that exists within Class C or D controlled airspace, but is not the so-called “primary” airport on which the airspace is based. The satellite airport may or may not have an operating control tower.) This provides an opportunity to review the communications requirements for airports in controlled airspace (different controlled airspaces are depicted or coded on aeronautical charts), and helps us to better understand the interpretation.
For Class C or D controlled airspace, a pilot operating to or from the primary (not the satellite) airport, or flying through that airspace, must establish two-way radio communications with the ATC facility providing air traffic services to the airspace and the primary airport. That must be done prior to entering the airspace, and communications must be maintained while in that airspace and as instructed by ATC. For Class B airspace, the basic communications requirement is the same and arguably more stringent in that all aircraft in that airspace must operate with an ATC clearance. For airports in Class E controlled airspace, the basic communications requirement is still the same but less stringent in that the airspace in which the communications requirement applies is smaller, and uniform for all airports in Class E airspace. The airspace is uniformly defined to include 4 nm from the airport, up to and including 2,500 feet agl (expressed in mean sea level on the aeronautical charts). Even if the airport is in Class G (uncontrolled) airspace, and has an operating control tower, the basic communications requirement and the “communications” airspace dimensions, though uncontrolled, are the same as Class E controlled airspace.
The added complexity of the requirement comes with departures from a satellite airport, and the requirement differs depending on whether the satellite airport has an operating control tower. A pilot departing from a satellite airport that has an operating control tower “must establish and maintain two-way radio communications with the control tower, and thereafter as instructed by ATC,” while operating in that airspace (this provision, applicable to a satellite airport with an operating control tower, is involved in the interpretation I will discuss). The requirement is necessarily different for a pilot departing from a satellite airport without an operating control tower—then, the pilot must establish and maintain two-way radio communications with the air traffic control facility having jurisdiction over the airspace (approach control/tower) as soon as practicable after departing; that is, after becoming airborne and already in the controlled airspace. To minimize the time in which the aircraft is not in communication with the ATC facility controlling the airspace, the FAA establishes departure procedures for the airport. The departure procedures typically steer the aircraft away from the primary airport.
The scenario posed is this: “A pilot departs from a satellite airport and establishes communication with the control tower. The satellite airport’s operating control tower cleared the pilot to depart and then instructed the pilot to remain on frequency. Does establishing and maintaining communication with the satellite control tower satisfy the requirements of FAR 91.130(c)(2)(i), or does the regulation require the pilot to then subsequently establish two-way radio communication with a separate ATC facility? In this scenario, the pilot must attempt to contact Class C departure control on a second radio and/or slow down or otherwise linger in the satellite control tower’s airspace until the pilot receives permission to switch frequency and contact Class C departure. This scenario presents an interesting dilemma for pilots.”
The FAA chief counsel answers that “a pilot that establishes communication with the satellite’s operating control tower and is then instructed to remain on frequency is not in violation of Section 91.130(c)(2)(i) by remaining in communication with that tower. The pilot need not establish subsequent communication with a separate ATC facility to satisfy the requirement…unless instructed to do so by the satellite airport’s operating control tower.” A good answer for pilots.
The interpretation reminds us that FAA ATC procedures require that there be coordination between the controllers controlling adjacent airspaces. Pilots usually are not privy to the coordination between the different facilities, though they are generally aware that it occurs. In a situation where the controller does not want the pilot to change frequency but the pilot is expecting or may want a frequency change, the controller is directed to instruct the pilot to “remain this frequency.” That is what is postulated in the scenario presented. The answer is that the pilot must comply with the instruction, even if it takes the aircraft into airspace controlled by a different ATC facility. The pilot may presume that coordination has taken place.
In case there is any doubt, there is another regulation binding on us that is relevant to the situation. It is the admonition in FAR 91.123 that when a pilot is uncertain of an ATC clearance (and equally true of an instruction), that pilot shall immediately request clarification from ATC.
John S. Yodice is an instrument- and multiengine-rated pilot who owns a Cessna 310.