(a) Earth station antennas shall not normally be authorized for transmission at angles less than 5[deg] measured from the horizontal plane to the direction of maximum radiation. However, upon a showing that the transmission path will be seaward and away from land masses or upon special showing of need for lower angles by the applicant, the Commission will consider authorizing transmissions at angles between 3[deg] and 5[deg] in the pertinent directions. In certain instances, it may be necessary to specify minimum angles greater than 5[deg] because of interference considerations.
(b) ESVs making a special showing requesting angles of elevation less than 5[deg] measured from the horizontal plane to the direction of maximum radiation pursuant to (a) of this Section must still meet the effective isotropically radiated power (e.i.r.p.) and e.i.r.p. density towards the horizon limits contained in Sec. 25.204(h) and (i).
(c) VMESs making a special showing requesting angles of elevation less than 5[deg] measured from the horizontal plane to the direction of maximum radiation pursuant to (a) of this section must still meet the EIRP and EIRP density towards the horizon limits contained in Sec. 25.204(j).
(d) While on the ground, ESAAs shall not be authorized for transmission at angles less than 5[deg] measured from the plane of the horizon to the direction of maximum radiation. While in flight there is no minimum angle of antenna elevation. [70 FR 4784, Jan. 31, 2005, as amended at 74 FR 57099, Nov. 4, 2009; 78 FR 14927, Mar. 8, 2013]