For her Masters at one of Brazil’s leading universities, Malila Prado conducted a fascinating corpus study about pilot/controller communication. She compiled a corpus based on LiveATC’s Interesting recordings and investigated patterns with the most frequent lexical items. She also contrasted the grammar structures found in the corpus with the Glossary of Basic and Complex Structures from Doc 9835. You can read the abstract (in Portuguese and in English) or read the whole dissertation (in Portuguese only) here: http://www.teses.usp.br/teses/disponiveis/8/8147/tde-16062015-131340/pt-br.php .
Prado, M. (2015). Levantamento dos padrões léxico-gramaticais do inglês para aviação: um estudo vetorado pela Linguística de Corpus [Analysis of lexical-grammar patterns of aviation English: a study vectored by Corpus Linguistics] (Master dissertation). University of Sao Paulo, Sao Paulo, retrieved from Teses.usp.br.