Sec. 22.873  Construction period for commercial aviation air-ground 
          systems.

    Construction of a new commercial aviation air-ground system is 
considered to be completed for the purpose of this section and 
Sec. 22.142 when the number of ground stations specified in this section 
are constructed and operational.
    (a) Stage I. At least 25 ground stations must be constructed and 
operational within 3 years. Licensees must notify the FCC (FCC Form 489) 
as soon as this requirement is met. Service to subscribers may commence 
as soon as the notification is mailed. If service to subscribers is not 
commenced at that time, the notification must contain a statement to 
this effect.
    (b) Stage II. At least 50 ground stations must be constructed and 
operational within 5 years. Nationwide service to subscribers must 
commence within 5 years. Licensees must notify the FCC (FCC Form 489) as 
soon as these requirements are met.