Mobissimo

Airplanes really haven't changed much in the past 50 years.  The Boeing 737 is one of the first of the modern passenger jets, now, on its last legs as a viable commercial jet.

United was an early customer of the 737, taking delivery of its first one in 1968. The plane that flew on Wednesday was delivered in 1988.

United began phasing out the decades-old planes last year as fuel prices spiked. Fuel prices have come back down somewhat since then, but United is still shrinking its fleet because demand is lower.