National Center for the Advancement of Aviation Act of 2021 This bill establishes the National Center for the Advancement of Aviation to serve as a national independent forum to facilitate collaboration and cooperation between aviation and aerospace stakeholders to support and promote civil and military aviation and aerospace. The center must perform the following duties support the development of aviation and aerospace education curricula; support the professional development of educators using such curricula; promote aviation and aerospace employment opportunities; support Armed Forces personnel seeking to transition to a career in civil aviation or an aerospace-related field through outreach, training, apprenticeships, or other means; serve as a central repository for publicly available economic data, safety data, and research efforts related to the aviation and aerospace sectors; and serve as a forum, through symposiums, conferences, and other means as appropriate, for cross-disciplinary collaboration among aviation and aerospace stakeholders. Additionally, the center may issue grants to organizations that have experience in, and knowledge of, creating, developing, and delivering or updating (1) high school aviation curricula; or (2) aviation curricula used at institutions of higher education, secondary educations institutions, or by technical training and vocational schools.