Sec. 90.421  Operation of mobile units in vehicles not under the control 
          of the licensee.

    Mobile station transmitters may be installed in vehicles operated by 
persons other than the licensee as provided in the following paragraphs 
when necessary for the licensee to meet his requirements in connection 
with the activities for which he is licensed. The number of units so 
installed, together with units installed in vehicles operated by the 
licensee, must not exceed the number of mobile units authorized to the 
licensee. When an insufficient number of units is licensed to cover such 
additional units, the license must be modified to add a sufficient 
number of mobile units. The licensee is responsible for taking any 
necessary precaution to effectively eliminate the possibility of 
unauthorized operation of transmitters when not under the control of the 
licensee.
    (a) Public Safety Pool. (1) Mobile units licensed in the Public 
Safety Pool may be installed in any vehicle which in an emergency would 
require cooperation and coordination with the licensee, and in any 
vehicle used in the performance, under contract, of official activities 
of the licensee. This provision does not permit the installation of 
radio units in non-emergency vehicles that are not performing 
governmental functions under contract but with which the licensee might 
wish to communicate.
    (2) Additionally, units may be installed in the following:
    (i) Vehicles of contractors or other persons having a direct 
responsibility for official highway activities;
    (ii) Vehicles of forestry cooperators, and persons having a direct 
responsibility in the prevention, detection, and suppression of forest 
fires; and
    (iii) Mobile units licensed under Sec. 90.20(a)(2)(iii) may be 
installed in a vehicle or be hand-carried for use by any person with 
whom cooperation or coordinations is required for medical services 
activities.
    (b) Industrial/Business Pool. Mobile units licensed in the 
Industrial/Business Pool may be installed in the following:
    (1) Vehicles of persons furnishing under contract to the licensee 
and for the duration of the contract, a facility or service directly 
related to the activities of the licensee;
    (2) Vehicles operated by an organization or association comprised of 
interconnected electric utilities forming interconnections, power pools, 
or groups;
    (3) Vehicles of persons furnishing a private emergency road service 
to its members pursuant to a contract with the association; and
    (4) Vehicles operated by organizations providing, under contract, 
facilities or service in connection with railroad operation or 
maintenance including pickup, delivery, or transfer between stations of 
property shipped, continued in, or destined for shipment by railroad 
common carrier. Parties to the contract must comply with the provisions 
of Sec. 90.179.
    (c) In addition to the above, frequencies assigned to licensees in 
the Private Land Mobile Radio Services may be installed in the 
facilities of those who assist the licensee in emergencies and with whom 
the licensee must communicate in situations involving imminent safety to 
life or property.
[ 43 FR 54791 , Nov. 22, 1978, as amended at  44 FR 50603 , Aug. 29, 1979; 
 47 FR 19539 , May 6, 1982;  47 FR 42751 , Sept. 29, 1982;  61 FR 6576 , Feb. 
21, 1996;  62 FR 18933 , Apr. 17, 1997]

    Effective Date Note: At  62 FR 18933 , Apr. 17, 1997, Sec. 90.421 was 
amended by revising paragraphs (a) and (b), removing paragraphs (c) 
through (k), and redesignating paragraph (l) as paragraph (c), effective 
Oct. 17, 1997.