Avio-Diepen - A Proponent Company. When two of the world’s leading independent aerospace distributors combine, great things happen. Proponent is the fresh new identity representing not only the expertise of Kapco Global and Avio-Diepen as one united company, but also the unique capabilities and perspective the organization brings to the aerospace market. In addition to over 110 years of collective experience in supporting the MRO, OEM, and airline markets, our organization has a history of offering innovative inventory and supply chain management solutions to both OEM and aftermarket customers. Proponent combines the scale and agility of two of the world’s largest independent aircraft parts distribution businesses, with the passion, proficiency and know-how of a team dedicated to comprehensive customer service and innovative personalized solutions. Proponent is an employee-owned company, with 600 staff operating out of 12 facilities in 8 countries across the globe.