(a) An aeronautical advisory station (unicom) must provide service to any aircraft station upon request and without discrimination. A unicom must provide impartial information concerning available ground services.

(b)(1) Unicom transmissions must be limited to the necessities of safe and expeditious operation of aircraft such as condition of runways, types of fuel available, wind conditions, weather information, dispatching, or other necessary information. At any airport at which a control tower, control tower remote communications outlet station (RCO) or FAA flight service station is located, unicoms must not transmit information pertaining to the conditions of runways, wind conditions, or weather information during the hours of operation of the control tower, RCO or FAA service station.

(2) On a secondary basis, unicoms may transmit communications which pertain to the efficient portal-to-portal transit of an aircraft, such as requests for ground transportation, food or lodging.

(3) Communications between unicoms and air carrier must be limited to the necessities of safety of life and property.

(4) Unicoms may communicate with aeronautical utility stations and ground vehicles concerning runway conditions and safety hazards on the airport when neither a control tower nor FAA flight service station is in operation.

(c) Unicoms must not be used for air traffic control (ATC) purposes other than to relay ATC information between the pilot and air traffic controller. Relaying of ATC information is limited to the following:

(1) Revisions of proposed departure time;

(2) Takeoff, arrival or flight plan cancellation time;

(3) ATC clearances, provided a letter of agreement is obtained from the FAA by the licensee of the unicom.

(a) A unicom and any associated dispatch or control points must be located on the airport to be served.

(b) Only one unicom will be authorized to operate at an airport which does not have a control tower, RCO or FAA flight service station that operates on the published common traffic advisory frequency. At any other airport, the one unicom limitation does not apply, and the airport operator and all aviation services organizations may be licensed to operate a unicom on the assigned frequency.

(c) At an airport where only one unicom may be licensed, eligibility for new unicom licenses is restricted to State or local government entities, and to nongovernmental organizations (NGOs) that are authorized to apply for the license by a State or local government entity whose primary mission is the provision of public safety services. All applications submitted by NGOs must be accompanied by a new, written certification of support (for the NGO applicant to operate the applied for station) by the state or local government entity. Applications for a unicom license at the same airport, where only one unicom may be licensed, that are filed by two or more applicants meeting these eligibility criteria must be resolved through settlement or technical amendment.

(d) At an airport where only one unicom may be licensed, the license may be assigned or transferred only to an entity meeting the requirements of paragraph (c) of this section.

(e) An applicant for renewal of a unicom license shall be granted a presumptive renewal expectancy regardless of whether the applicant is eligible for a new unicom license under paragraph (c) of this section. Unless the renewal expectancy is defeated, applications that are mutually exclusive with the renewal application will not be accepted. The renewal expectancy may be defeated only upon a determination, following a hearing duly designated on the basis of a petition to deny or on the Commission's own motion, that the renewal applicant has not provided substantial service. For purposes of this paragraph, substantial service means service which is sound, favorable, and substantially above a level of mediocre service during the applicant's past license term. If the renewal expectancy is defeated, the renewal application will be dismissed unless the renewal applicant is eligible for a new unicom license pursuant to paragraph (c) of this section.

(f) At an airport where only one unicom may be licensed, when the Commission believes that the unicom has been abandoned or has ceased operation, another unicom may be licensed on an interim basis pending final determination of the status of the original unicom. An applicant for an interim license must notify the present licensee and must comply with the notice requirements of paragraph (g) of this section.

(g) An applicant for a unicom license, renewal or modification of frequency assignment at an airport which does not have a control tower, RCO or FAA flight service station must notify in writing the owner of the airport and all aviation service organizations located at the airport. The notice must include the applicant's name and address, the name of the airport and a statement that the applicant intends to file an application with the Commission for a unicom. The notice must be given within the ten days preceding the filing of the application with the Commission. Each applicant must certify upon application that either notice has been given and include the date of notification, or notice is not required because the applicant owns the airport and there are no organizations that should be notified.

(a) Only one unicom frequency will be assigned at any one airport. Applicants must request a particular frequency, which will be taken into consideration when the assignment is made. The frequencies assignable to unicoms are:

(1) 122.950 MHz at airports which have a full-time control tower or full-time FAA flight service station.

(2) 122.700, 122.725, 122.800, 122.975, 123.000, 123.050 or 123.075 MHz at all other airports.

(b) 121.500 MHz: emergency and distress only.

(a) A station operator need not be present when an automated unicom is in operation.

(b) Unicoms operating in an automated mode must comply with the requirements of paragraphs (1)-(5) of this section, in addition to the requirements applicable to non-automated unicom operations.

(1) An automated unicom must transmit only in response to interrogating signals from aircraft, including but not limited to the brief keyed RF signals specified in § 87.187(y).

(2) An automated unicom must monitor the unicom frequency prior to transmission, and provide a brief delay between the aircraft's interrogating signal and the automatic unicom's response.

(3) Automated advisory transmissions must be as brief as possible, and must never exceed one minute in length.

(4) An automated unicom may not provide weather information at an airport that has an operational, FAA-certified, automatic weather facility, unless the unicom itself is certified by the FAA.

(5) If weather information is provided by an automated unicom:

(i) Weather sensors must be placed in order to adequately represent the weather conditions at the airport(s) to be served;

(ii) The weather information must be proceeded by the word “advisory;”

(iii) The phrase “automated advisory” must be included when the weather information was gathered by real-time sensors or within the last minute; and,

(iv) The time and date of the last update must be included when the weather information was not gathered within the last minute.

(c) Only one automated unicom may be operated at an uncontrolled airport. Prior to the operation of an automated unicom at an airport with more than one unicom licensee, all of the licensees at that airport must sign a letter of agreement stating which licensee(s) control the automated unicom operations, and, if control is to be shared among several operators, how that control will be divided or scheduled. The original or a copy of the letter of agreement must be kept with each licensees' station records. Within 90 days of the date upon which a new unicom operator is licensed at an airport where more than one unicom is authorized, and an automated unicom is being operated, an amended letter of agreement that includes the new licensee's signature must be signed or automated unicom operations must cease.