Sec.  17.45   Temporary warning lights.

   During construction of an antenna structure, for which red obstruction
   lighting is required, at least two 116- or 125-watt lamps (A21/TS) enclosed
   in  aviation  red  obstruction light globes, shall be installed at the
   uppermost point of the structure. The intensity of each lamp shall not be
   less than 32.5 candelas. In addition, as the height of the structure exceeds
   each level at which permanent obstruction lights will be required, two
   similar  lights shall be installed at each such level. These temporary
   warning lights shall be displayed nightly from sunset to sunrise until the
   permanent obstruction lights have been installed and placed in operation,
   and shall be positioned so as to insure unobstructed visibility of at least
   one  of  the lights at any normal angle of approach. If practical, the
   permanent obstruction lights may be installed and operated at each required
   level as construction progresses.

   [ 32 FR 11273 , Aug. 3, 1967, as amended at  39 FR 26157 , July 17, 1974;  42 FR 54826 , Oct. 11, 1977]