On this continuum, the level of professional skepticism moves from something less than complete trust, to a neutral mind-set, to presumptive doubt, and all the way to complete doubt. The appropriate level of skepticism to apply is initially determined only after a careful and rigorous risk assessment.
1 The longest flying aircraft flying from Kansas City, MO to Cancun, Mexico during the 2009 year was a AirbusNdustrie's A319 flown by Frontier.  Back in 2009 there was just one airline company operating flights between Kansas City and Cancun.
Flight time from Miami to Cancun is 1 hour 35 minutes. Non-Stop flight duration from MIA to CUN is 1 hour 35 minutes (Operated by US Airways). Non-stop flights take anywhere between 1 hour to 9 hours. Quickest one-stop flight takes close to 6 hours. However, some airlines could take as long as 25 hours based on the stopover destination and waiting duration.