Our objective in this piece is to provide a comprehensive comparative breakdown of United Airlines (NYSE: UAL) and Delta Air Lines (NYSE: DAL). We aim to discuss aircraft mix, age, and gauge to reveal where and how each airline chooses to compete. These airlines each have their own maintenance strategy and retrofit cadence, both of which help the carrier exhibit a balance-sheet posture and overall capital discipline. Mapping narrowbody and widebody portfolios by family and subtype will help highlight seating density and premium share, while also allowing us to examine further utilization patterns that convert assets into revenue.