CO, like all the major US carriers, was quick to order the 747 for its route network and took delivery of four (I think) of the type in the early 1970s, the 747s were assigned to
CO's key routes at the time, being the
ORD-
DEN-
LAX service and the
ORD-
LAX-
HNL service. And, just like most of the other US carriers,
CO had an impossible time keeping the 350 seats on its 747 filled......the aircraft was simply too big for domestic services. After a few years time,
CO parked and then sold off its 747-124 fleet, and its recently acquired DC10-10s took over as the biggest airliner in
CO's fleet.
CO was not alone in failing to make the 747 work on US domestic services.....
DL had a small fleet of 747s,
AA flew 747s on its domestic network, etc, etc.....the aircraft was just too big (also note that during the early 1970s, the US experienced the first fuel crisis which greatly increased the price of fuel at the time).
And, as pointed out above,
CO had a second round with the 747, this time after the Peoplexpress merger in 1987....
PE had a fleet of five (again, I am no longer certain with the numbers) second hand 747s which it flew on its transcon and transatlantic routes......
PE also flew the 747 on the
EWR-
DEN route for a short time after
PE purchased Frontier One and was connecting its
EWR hub and Denver hub.
CO retained the 747s for several years after the merger,
CO flew the 747s on some transatlantic services and eventually the 747s found their way to the
CO Air Mike operation prior to being retired in the late 1990s, curiously, again in favor of DC10s which became the largest type in the newly reorganized
CO fleet.