DENVER -- The FOX31 Problem Solvers analyzed the last 385,208 flights leaving Denver International Airport to glean delay patterns for all airlines.
For starters, never take a flight scheduled to leave between 6 p.m. and 8 p.m., especially on a Monday or a Thursday. There is a 1 in 5 chance of a delay of more than 30 minutes during those times.
Weather conditions are part of the delay problems at DIA, but a statistical analysis discovered not all airlines are equal.
Over the course of 20 months, JetBlue flights left more than 15 minutes late 32 percent of the time. Spirit Airlines was next at 24 percent.
Data from the U.S. Bureau of Transportation show United Airlines had 6,714 flights that left more than 60 minutes past its promised wheels up time -- 7 percent of all its DIA outbound flights.
Spirit (9.33 percent) and JetBlue (9.56 percent) topped the hour-plus late list with slightly higher percentages.
Passengers say the most irritating method of delay is when airlines pull away from the gate on time, then taxi out and let passengers sit inside the jet on the tarmac for extended periods of time.
Sky West Airlines is the most prominent player in the database for this trick. It had 7,618 of its outbound flights from DIA -- 8.56 percent -- delayed more than 30 minutes after leaving the gate.
There were 686 of those flights that put passengers waiting in their seats on the tarmac more than one hour.
“That does get annoying cause there’s nothing to do," frequent flier Greg Woitte said. "You can’t go anywhere. You’re not getting to your final destination. Plus you can’t use your equipment -- all your electronic devices so you can’t get any work done either.”
According to DIA, the airlines are mostly to blame for delays, but plenty of travelers say airport operations can also add to the problem.
“When you don’t have enough people at security to get through to make your flight. That’s kind of game changer right there,” a passenger said. "It’s more important than the delays. It’s frustrating that the plane’s on time and security doesn’t get you through to meet it.”
In six years of data of flights leaving DIA in December, the least busy time to fly is on Christmas Eve, with the busiest time period on Dec. 27.
"The time frame you are looking at was a particularly difficult time for our operations, across all of our network, especially the summer of 2015," Spirit Airlines said in a statement.
"Since this period we have made several adjustment to improve our reliability and on-time performance. Since May of 2015 we have seen significant improvement in on-time performance across our entire network.
"Looking at our most recent performance, for the months of Sept/Oct/Nov those averages were 8.5 percent for delays more than 15 minutes and 3 percent for delays more than an hour."
United Airlines, which also owns and represents Sky West, said the extra time taken to deice Sky West jets is the main reason for the tarmac-related delays.
In addition, United Airlines said it has a better on-time pattern out of DIA "then the average of all other airlines" and it "continue(s) to increase the on-time gap."