This is a sole-source solicitation for a flight-critical part, requiring government source approval prior to contract award. Only previously approved sources have been solicited, and the approval process for a new source is typically too lengthy to delay an award. Unapproved sources must submit a detailed source approval request with their proposal, using specified NAVSUP WSS brochures. Proposals from non-approved sources must be received within 45 days of the synopsis publication to be considered. The Government intends to negotiate with only one source but will consider all responses to determine if a competitive procurement is possible.