This is a sole-source procurement for a flight-critical aerospace part requiring Government source approval before contract award. Only sources previously approved by the Government for this item have been solicited, though all responsible sources may express interest and submit capability statements. Any alternate source must comply with the design control activity's qualification procedures and must submit all required Source Approval Brochure data with its offer. Approval of a new source normally cannot be completed in time for award, and the Government may continue the acquisition based on fleet support needs. The contract action is intended to be negotiated with only one source under FAR 6.302-1.