This is a procurement for 6 units of a flight-critical part that requires Government source approval prior to contract award. The work is delivery FOB Origin. Only sources previously approved by the Government for this specific item have been solicited, as the technical data is not economically available to support open competition. Unapproved sources must submit a detailed source approval request with their proposal, and the time required for new source approval is normally too long to delay an award. Offers that fail to provide or document the submission of all required source approval data will not be considered.