The Department of the Navy intends to award a firm-fixed-price contract modification to Collins Aerospace for retrofitting Government-furnished Block I Digital Red Switch System (DRSS) production support assets to a Block II configuration, supporting E-6B aircraft sustainment. This action is a sole-source award under the authority of 10 U.S.C. 3204(a)(1), as only Collins Aerospace can provide the required highly specialized services without unacceptable delays. The modification will be issued under an existing Basic Ordering Agreement, and the effort is not set aside for small business. This notice is not a request for competitive proposals, though responsible sources may submit information for consideration. No budget figures or performance location are specified.