Ответ:STC: A supplemental type certificate (STC) is a type certificate (TC) issued when an applicant has received FAA approval to modify an aeronautical product from its original design. The STC, which incorporates by reference the related TC, approves not only the modification but also how that modification affects the original design. OEM stands for Original Equipment Manufacturer, for example a part for a Piper that is manufactured by Piper.