The proceedings of the first Language Testing Forum in 1980 were published in "ELT Documents 111: Issues in Language Testing" (Alderson & Hughes, 1981). Discussants at the 1980 Forum raised a number questions on Language for Specific Purposes (LSP) testing relating, notably, to test specificity, test content, the relationship between subject matter knowledge and language knowledge and predicting real-life language performance. The 2010 Language Testing Forum looked back at the last three decades in language testing to reflect on what developments, if any, have occurred. Following the 2010 Forum, this article addresses the questions raised in 1980 with reference to testing for a very specific purpose--the International Civil Aviation Organisation's Language Proficiency Requirements for pilots and air traffic controllers. In analysing the testing context--aeronautical radiotelephony communications--the author argues that, in spite of theoretical and methodological advances in LSP testing, these questions are still as relevant to testing LSP today as they were in the early 1980s.