Sec. 121.121 - En route navigational facilities.
(a) Except as provided in paragraph (b) of this section, no certificate holder conducting supplemental operations may conduct any operation over a route unless nonvisual ground aids are --
(1) Available over the route for navigating airplanes within the degree of accuracy required for ATC; and
(2) Located to allow navigation to any airport of destination, or alternate airport, within the degree of accuracy necessary for the operation involved.
(b) Nonvisual ground aids are not required for --
(1) Day VFR operations that can be conducted safely by pilotage because of the characteristics of the terrain;
(2) Night VFR operations on lighted airways or on routes that the Administrator determines have reliable landmarks adequate for safe operation; or
(3) Operations on route segments where the use of celestial or other specialized means of navigation is approved.
(c) Except for those aids required for routes to alternate airports, the nonvisual ground navigational aids that are required for approved of routes outside of controlled airspace are specified in the certificate holder's operations specifications.
[Doc. No. 6258, 29 FR 19195, Dec. 31, 1964, as amended by Amdt.
121-253, 61 FR 2611, Jan. 26, 1996]