The main purpose of this book aims at exploring the English language needs of the pilots and jet-fighter maintenance technicians at H Air Force Base in Taiwan. English is the lingua franca of science and technology; therefore, English is also the accepted lingua franca of H Air Force Base. It is essential for pilots, technicians, commissioned officers, and non-commissioned officers to apply English skills in the form of verbal or written discourses in their domain fields or other settings in order to complete the tasks regarding their jobs. Through in-depth interviews with English teachers, pilots, and technicians and a questionnaire survey, this book found that English abilities are vital to the flight and jet-fighter maintenance fields. Also, the means analysis revealed some negative variables which will impede the ESP implementation at work settings. Finally, based on the research questions and findings, this book presents some integral suggestions for future ESP courses to help meet the job requirements of the pilots and technicians.