. we recognize sales under long-term contracts in the aerospace and technologies segment using percentage of completion under the cost-to-cost method of accounting . the 2011 contract mix consisted of approximately 60 percent cost-type contracts , which are billed at our costs plus an agreed upon and/or earned profit component , and 33 percent fixed-price contracts . the remainder represents time and material contracts , which typically provide for the sale of engineering labor at fixed hourly rates