This is a specialized procurement for 11 flight-critical parts that requires Government source approval prior to contract award. Only previously approved sources have been solicited, and the Government intends to negotiate with a single source. Unapproved sources must submit detailed qualification information with their proposal, as the approval process is lengthy and an award cannot be delayed for it. Proposals from other sources will be considered if received within 45 days of the synopsis publication. The delivery terms are FOB Origin.