All of our aircraft are on different maintenance cycles...... there are hourly checks which have to be done after a certain number of hours, cycle checks, daily checks, weekly, monthly, etc.....

It isn't uncommon for an airplane to run for three, four, five days straight and then be brought into the hangar for one of its checkups. Anytime you taxi by the maintenance hangars there in IAH or EWR you will see a handful of aircraft pulled into the bays getting their checks done.

This particular aircraft is apparently pulled into the barn for the day getting its wax job, lube job, etc......or an engine changed because one failed. Gotta be one or the other......