The document discusses various noise mitigation measures for airports, including purchase assurance, sales assurance, and transaction assistance. Purchase assurance involves the airport purchasing a home at fair market value, sound insulating it, and reselling it subject to an easement. Sales assurance assures homeowners the fair market value when selling subject to an easement. Transaction assistance pays costs associated with selling such as realtor fees. The FAA requires appraisals to consider noise and easements to remain with the land. Costs are reimbursable under the Airport Improvement Program if part of an approved noise compatibility program.