Jean Raebel Leaves The Supervisory Board Due To Old Age. Irmgard Schmid-Maybach, Daughter Of Karl Maybach, Is Elected To The Supervisory Board Of MTU Friedrichshafen. In 1967, Jean Raebel Retires And Becomes Member Of The Supervisory Board. Irmgard Schmid-Maybach Is A Member Of The Supervisory Board Until 2005 And Since 2007, She Is An Honorary Member For Lifetime.