Since 2019, a concession or authorization to provide public air transport services may only be granted to a legal entity incorporated under Brazilian laws, with headquarters and administration in the country. Before, foreign participation in air transport companies was limited to 20% and directors of such companies had to be exclusively Brazilian nationals.
"Art. 180. The exploitation of public air services will always depend on prior concession, in the case of regular air transport, or authorization in the case of non-scheduled air transport or specialized services.
Art. 181. The concession or authorization will only be granted to a legal entity incorporated under Brazilian laws, with headquarters and administration in the country.
I - headquartered in Brazil; [repealed by Law No. 13.842 of 2019]
II - at least 4/5 (four fifths) of the capital with voting rights, belonging to Brazilians, this limitation prevailing in the eventual increases of the capital stock; [repealed by Law No. 13.842 of 2019]
III - direction entrusted exclusively to Brazilians. [repealed by Law No. 13.842 of 2019]
§ 1° Shares with voting rights must be nominative if they are companies incorporated in the form of a corporation, whose statutes must expressly prohibit the conversion of preferred shares without voting rights into shares with voting rights. [repealed by Law No. 13.842 of 2019] 
§ 2 The issuance of preferred shares may be allowed up to the limit of 2/3 (two thirds) of the total number of shares issued, with restrictions not provided for in this Code not prevailing. [repealed by Law No. 13.842 of 2019]
§ 3 The transfer to foreigners of shares with voting rights, which are included in the margin of 1/5 (one fifth) of the capital referred to in item II of this article, depends on the approval of the aeronautical authority. [repealed by Law No. 13.842 of 2019][...]" (Aeronautical Code (Law No. 7,565 of December 19, 1986), as amended by Law No. 13.842 of 2019, Articles 180 and 181 [google translation])
Aeronautical Code (Law No. 7,565 of December 19, 1986), as amended by Law No. 13.842 of 2019
Law No. 13,842, of June 17, 2019, Amending Law No. 7,565, of December 19, 1986 (Brazilian Aeronautical Code). 
[<a href="http://www.planalto.gov.br/ccivil_03/Leis/L7565.htm">Code</a>],[<a href="http://www.planalto.gov.br/ccivil_03/_ato2019-2022/2019/lei/L13842.htm">Law</a>]