The below paper is the critical analysis of research methods used in two papers, first is Airport route development: A survey of current practice by Halpern & Graham (2015) and second is Air route suspension: The role of stakeholder engagement and aviation and non-aviation factors by Lohmann & Vianna (2016). Although, both the studies are focused on evaluating operations of airport industry but adopted different research methods for the purpose of collecting information and drawing valid findings.