Note: This is not what the law is right now. This is what the law will be, effective August 27, 2016. Additions to existing regulations are shown in blue. In short, the Special Rule for Model Aircraft from FMRA Section 336 has been codified into FAR Part 101.
PART 101—MOORED BALLOONS, KITES, AMATEUR ROCKETS, UNMANNED FREE BALLOONS, AND CERTAIN MODEL AIRCRAFT
§101.1 Applicability.
(a) This part prescribes rules governing the operation in the United States, of the following:
(1) Except as provided for in §101.7, any balloon that is moored to the surface of the earth or an object thereon and that has a diameter of more than 6 feet or a gas capacity of more than 115 cubic feet.
(2) Except as provided for in §101.7, any kite that weighs more than 5 pounds and is intended to be flown at the end of a rope or cable.
(3) Any amateur rocket except aerial firework displays.
(4) Except as provided for in §101.7, any unmanned free balloon that—
(i) Carries a payload package that weighs more than four pounds and has a weight/size ratio of more than three ounces per square inch on any surface of the package, determined by dividing the total weight in ounces of the payload package by the area in square inches of its smallest surface;
(ii) Carries a payload package that weighs more than six pounds;
(iii) Carries a payload, of two or more packages, that weighs more than 12 pounds; or
(iv) Uses a rope or other device for suspension of the payload that requires an impact force of more than 50 pounds to separate the suspended payload from the balloon.
(5) Any model aircraft that meets the conditions specified in § 101.41. For purposes of this part, a model aircraft is an unmanned aircraft that is:
(i) Capable of sustained flight in the atmosphere;
(ii) Flown within visual line of sight of the person operating the aircraft; and
(iii) Flown for hobby or recreational purposes.
(b) For the purposes of this part, a gyroglider attached to a vehicle on the surface of the earth is considered to be a kite.
§ 101.41 Applicability.
This subpart prescribes the rules governing the operation of a model aircraft that meets all of the following conditions as set forth in section 336 of Public Law 112-95:
(a) The aircraft is flown strictly for hobby or recreational use;
(b) The aircraft is operated in accordance with a community-based set of safety guidelines and within the programming of a nationwide community-based organization;
(c) The aircraft is limited to not more than 55 pounds unless otherwise certified through a design, construction, inspection, flight test, and operational safety program administered by a community-based organization;
(d) The aircraft is operated in a manner that does not interfere with and gives way to any manned aircraft; and
(e) When flown within 5 miles of an airport, the operator of the aircraft provides the airport operator and the airport air traffic control tower (when an air traffic facility is located at the airport) with prior notice of the operation.
§ 101.43 Endangering the safety of the National Airspace System.
No person may operate model aircraft so as to endanger the safety of the national airspace system.