New York Codes, Rules and Regulations
Title 21 - Miscellaneous
Chapter XXIV - The Port Authority Of New York And New Jersey
Subchapter D - Air Terminals
Article 1 - John F. Kennedy International, La Guardia and Newark Airports
Part 1261 - Aircraft Operations
Starting, Taxiing, Towing and Parking
Section 1261.47 - Moving aircraft to be in contact with tower

Whenever any aircraft is being taxied, towed or otherwise moved on the public landing area, public ramp and apron area, public passenger ramp and apron area, or public cargo ramp and apron area, there shall be a person attending the controls of the aircraft who shall monitor by radio the transmitting frequency in use by the control tower or who, if necessary, will cause that frequency to be monitored by another person in the aircraft at the time. In the event of radio equipment failure, the control tower may use an aldis lamp for communication.