Exhibit 99.1 INNOVATIVE SOLUTIONS & SUPPORT dba INNOVATIVE AEROSYSTEMS REPORTS FISCAL 2025 FOURTH QUARTER AND YEAR ENDED 2025 RESULTS Exton, PA, December 18, 2025 – Innovative Solutions & Support, Inc. (Nasdaq: ISSC) dba Innovative Aerosystems and its subsidiaries ("IA") or the "Company"), a leading provider of advanced avionic solutions for commercial, business aviation and military markets, today announced its financial results for its fiscal 2025 fourth quarter and full year ended September 30, 2025. FOU ...