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]