United Airlines has a huge Boeing 737 fleet of almost 540 aircraft consisting of both the 737NG (Next Generation) and 737 MAX series. With its 737 MAX fleet currently at around 210 airframes, the ...

The original run of 727s was the 727-100 model. After just a few years, due to a demand to fit in even more passengers per flight, Boeing produced the 727-200, which is 20 feet longer and can hold ...

United Airlines' oldest Boeing 737s are several 737-700s inherited from its merger with Continental Airlines. Most of Chicago-based United's -700 airframes are over 25 years old.