This is a sole-source solicitation for the U.S. Department of Transportation's Volpe Center, intended for Washington State University to provide technical analyses and assessments of sustainable aviation fuels in support of the FAA's representation at ICAO/CAEP. The work includes updating Rules of Thumb, U.S. capacity databases, and a Fuel Accounting Report for an ICAO-wide assessment due in early 2027. A firm-fixed-price purchase order with a base and six optional CLINs will be awarded. No budget amount is specified in the notice. No location for performance of services is stated.