Sec.  5.71   License period.

   (a)  The regular license period for stations in the Experimental Radio
   Service is either 2 or 5 years. An applicant desiring to apply for a 5-year
   license  must provide justification for its need for a license of that
   duration. A license may be renewed upon an adequate showing of need.

   (b) A license will not be granted for a period longer than that which is
   required for completion of the experimental project. If such period is
   estimated to be less than 2 years, or between 2–5 years, a statement to that
   effect by the applicant may facilitate grant of the application. See also
    Sec. 5.69 of this part.