This is a sole-source solicitation for a flight-critical part, requiring government source approval prior to contract award, and only previously approved sources have been solicited. The Government intends to negotiate with only one source, but all responsible sources may submit proposals or capability statements. Proposals received within 45 days of the synopsis publication will be considered. Interested parties may identify their capability to satisfy the requirement with a commercial item within 15 days of this notice. The part requires engineering source approval, and an alternate source must qualify through specific procedures approved by the cognizant Government engineering activity.