This is a sole-source solicitation for a flight-critical part, intended only for government-approved sources. 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. The part requires government source approval prior to contract award, and unapproved sources must submit detailed qualification information with their proposal. The time required for new source approval is normally too lengthy to delay an award.