About VREF
VREF Aircraft Value Reference, Appraisal & Litigation Consulting Services was founded in 1994 and is based in Buffalo Grove, Illinois, with representation in over 40 global locations.
VREF provides industry-leading aircraft valuation data through online subscription services (SaaS), published quarterly books, and is the largest aircraft appraisal firm worldwide, completing over 20,000 valuations a month.
VREF provides appraisals and advisory services to a worldwide client base of aviation professionals, including every major OEM, financial institutions, broker/dealer, and insurance underwriters, as well as the general consumer. VREF is the official Valuation Service and Appraisal company for the AOPA and the only aircraft appraisal software endorsed by the American Society of Appraisers (ASA).
Meet the VREF Team
Jason Zilberbrand, ASA, CAA, ISA AM, AOA AM, MRAeS
President & CTO
312-961-0934 | [email protected] | Linkedin Profile | Curriculum Vitae


After spending 25 years in General Aviation working directly with aircraft owners, operators, and owning and operating his own aircraft, Jason knows the international aviation marketplace. He is considered an expert in aircraft valuations and aircraft transactions, and his background is diverse with knowledge in technology and aviation.
Areas of aviation expertise include:
• Business aviation transactions
• Breach of contract disputes
• Corporate breach of contract
• Back to back disputes
• Agent agreements
• Aircraft valuation
• Aircraft diminution of value, post-accident damage, insurance claims
• Aircraft Depreciation, historical depreciation
• Engine maintenance programs, Airframe Maintenance Programs, Power by the hour programs contracts, and standards
• Statistical analysis of aircraft values
• Aircraft resale, aircraft import/export
Jason graduated in the top 1% of his class with National Honors from Roosevelt University in Chicago as well as a lifetime member of The Franklin Honor Society and a member of the Royal Aeronautical Society. Jason is an avid Triathlete, marathon runner, swimmer, and cyclist and enjoys spending time with his family. Jason is currently the Director of Public Relations for ASA Chicago Chapter 33.
Ken Dufour, ASA, MAM, ATP, CFI
CEO
815-633-1684 | [email protected] | Linkedin Profile

Dufour’s aviation career spans more than 30 years of involvement. He has held positions as regional vice president, area manager, and regional marketing manager for leading industry companies like Gulfstream Aerospace, Honeywell, BF Goodrich Aerospace, AlliedSignal, and Litton Aero Products.
Dufour earned a bachelor’s degree in professional Aeronautics and a Master of Aviation Management degree from Embry-Riddle Aeronautical University in Daytona Beach, Florida. He is a licensed Airline Transport Pilot and a Certified Flight Instructor for Single-Engine, Multi-Engine and Instruments. Dufour is a member of the American Society of Appraisers, where he holds the designation of Accredited Senior Appraiser (ASA). Previously representing the National Aircraft Finance Association on its Board of Directors, Dufour now serves as an active member of the organization.
Leo V. Heidemann, ASA
Senior Aircraft Appraiser
815-519-7311 | [email protected] | Linkedin Profile | Curriculum Vitae
