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No Radio No Transponder Operations in Class D Airspace in a Mode C Veil
Wow, that title is a mouthful!! But it's true; aircraft can be operated, under certain circumstances, without a radio or a Mode C transponder within Class D airspace that's within a mode C veil. Rules and regulations often have exceptions, and the rules we call the Federal Air Regulations (FARs) are no different. There are in fact exceptions to the rules requiring two-way radio communications in Class D airspace and a Mode C transponder in the 30 nautical mile mode C "veil".
There are two main areas of discussion here, one dealing with that of the Mode C transponder requirement and the second requirement of two-way radio communications. I will deal with each of these issues separately. (For the purposes of this discussion I am not including any emergency procedures exemptions in this outline.)
There are two exceptions to the Mode C transponder requirement in the FAA regulation Part 91. One for gliders, balloons, and those aircraft which do not have an electrical system, and a second exemption for those who do not have a transponder installed, or who's transponder is not functioning.
First, aircraft which were not originally certificated with an engine-driven electrical system can operate within the mode C Vail without a transponder. This is allowed by FAR 91.215(b)(3), which states:
(3) Notwithstanding paragraph (b)(2) of this section, any aircraft which was not originally certificated with an engine-driven electrical system or which has not subsequently been certified with such a system installed, balloon or glider may conduct operations in the airspace within 30 nautical miles of an airport listed in appendix D, section 1 of this part provided such operations are conducted—
(i) Outside any Class A, Class B, or Class C airspace area; and
(ii) Below the altitude of the ceiling of a Class B or Class C airspace area designated for an airport or 10,000 feet MSL, whichever is lower;
Note that this exception does not allow operations within Class B or C airspace, but only within the 30 nautical mile mode C "veil" which exists around the primary airport in Class B airspace.
The second exception authorizes air traffic control (ATC) to allow any aircraft to deviate from mode C requirements. This exception is outlined in FAR 91.215(d), which states:
(d) ATC authorized deviations. Requests for ATC authorized deviations must be made to the ATC facility having jurisdiction over the concerned airspace within the time periods specified as follows:
(1) For operation of an aircraft with an operating transponder but without operating automatic pressure altitude reporting equipment having a Mode C capability, the request may be made at any time.
(2) For operation of an aircraft with an inoperative transponder to the airport of ultimate destination, including any intermediate stops, or to proceed to a place where suitable repairs can be made or both, the request may be made at any time.
(3) For operation of an aircraft that is not equipped with a transponder, the request must be made at least one hour before the proposed operation.
Note that there is no specific requirement for the request for deviation to come to ATC through any particular means. The request can be made by telephone or by radio. Note too that if the aircraft is not equipped with a transponder at all, the request must be made at least an hour before the operation is to take place, but if the aircraft has a transponder installed that is malfunctioning the request can be made at any time.
No radio operations may be conducted in Class D airspace as long as the Air Traffic Control facility having jurisdiction over the airspace provides the pilot permission to operate without a radio. The ATC Facility you would contact is the air traffic control tower overseeing the airspace. The pilot should call the particular ATC tower responsible and submit his request including the estimated time of arrival, type and color of the aircraft. The tower will typically then ask the pilot to enter the airspace in a particular manner and within a specific time frame. The regulation dealing with this permission is as follows:
“91.129 Operations in Class D airspace.
(a) General. Unless otherwise authorized or required by the ATC facility having jurisdiction over the Class D airspace area, each person operating an aircraft in Class D airspace must comply with the applicable provisions of this section. In addition, each person must comply with §§ 91.126 and 91.127. For the purpose of this section, the primary airport is the airport for which the Class D airspace area is designated. A satellite airport is any other airport within the Class D airspace area.
(b) Deviations. An operator may deviate from any provision of this section under the provisions of an ATC authorization issued by the ATC facility having jurisdiction over the airspace concerned. ATC may authorize a deviation on a continuing basis or for an individual flight, as appropriate.
As you can see, by combining the deviations allowed in the transponder and radio communications requirements, a pilot could operate an aircraft in Class D airspace that lies within the mode C veil even though the aircraft is not equipped with a radio or a transponder so long as the aircraft meets the requirements of the mode C deviation, and the pilot requests a deviation from the two-way radio communications requirement for the Class D airspace.