Who holds what
Behind every certified design, modification and piece of approved equipment is an organisation the FAA holds responsible. These are the names that appear most, each with a page gathering everything under it. Type certificate holders are listed on the certificates page.
Approved modifications companies holding the most supplemental type certificates
Equipment approvals companies approved to make equipment by class (radios, GPS, tires, seat belts, batteries…)
Source: FAA Dynamic Regulatory System, as of October 7, 2026. Names as the FAA records them; the same company can appear under several spellings.