Answer:

SSS

AnswerCrossword Clue
SSS1970's lottery org.
SSSDraft agcy.
SSSDraft inits.
SSSDraft org.
SSSGovt. agcy.
SSSConscription org.
SSSFormer draft org.
SSSGen. Hershey directed it, 1941-70
SSSSound as a tire goes flat
SSSDraft init.
SSSLetters for the draft?
SSSRecruiting org
SSSMedium quality?
SSSFrying bacon sound
SSSGas leak sound
SSSSizzling sound
SSSConcordes, e.g., familiarly
SSS1-A issuer
SSSLottery org.
SSSDraft initials
SSSDeflation sound
SSSHissing sound
SSSRadiator sound
SSSSound from a flat
SSSSnake's warning
SSSDraft letters
SSSOrg. concerned with drafts
SSSOrg. that registers 18-to-25-year-olds
SSSMil. registration group
SSSOld military draft org.
SSSSerpent's sound
SSSFizzling sound
SSSGriddle sound
SSSOld lottery gp.
SSSSound of an escape?
SSSOrg. with a lottery
SSSKaa's sound in "The Jungle Book"
SSSReptilian warning
SSSSound of contempt
SSSContemptuous sound