The case of English for aviation maintenance: A multi-dimensional analysis of commercial aircraft manuals

Aircraft manufacturers use Simplified Technical English (STE) as a strategic tool to enhance the readability of aviation maintenance manuals and reduce comprehension errors. This standardized linguistic approach is essential for ensuring global aviation safety, especially as approximately 80% of maintenance technicians worldwide are non-native English speakers (NNES). This study employs Biber's Multi-Dimensional analysis framework (Biber, 1988, 1995, 2006) to investigate the linguistic characteristics of aviation maintenance English (AME) compared to general written English (GWE). The research is based on a 27-million-word corpus derived from maintenance manuals for all operational Boeing commercial aircraft families (737, 747, 757, 767, 777, and 787), which collectively serve over 150 countries and represent nearly half of the global fleet (Boeing, 2024). The analysis reveals that AME prioritizes informational density, minimizes abstract content, and uses comparable levels of elaboration to ensure clarity in safety-critical contexts. These findings challenge the misconception of simplified English as overly simplistic or reductive, demonstrating instead that strategic linguistic simplification enhances technical communication without compromising clarity. By highlighting the role of STE in supporting global interoperability, safety, and efficiency, this research offers valuable implications for English for Specific Purposes (ESP) pedagogy and the ongoing development of STE guidelines in aviation and other high-stakes industries.