Every Minute Counts

Lately I’ve been on delayed after delayed flight with United. I even started a single twitter thread where I just keep complaining about SFO-PHL, and PHL-SFO flights being chronically delayed. I started to wonder; is it just me having bad luck or is United getting worse overall with on time departures?

I’ve read a few articles recently citing data from the Bureau of Transportation Statistics and decided to go straight to the horses mouth for my analysis. I decided to focus on Departure Delays. Specifically, when the airline had scheduled push back and when they actually pushed back. I chose this path since airlines typically have more control over pushing back. Once pushed back they are under more control from Air Traffic Control and can be delayed for even more reasons. With that said, below were my steps for gathering data:

  1. Browsed to https://www.transtats.bts.gov/ONTIME/Departures.aspx 
  2. Under Statistics I chose Scheduled Departure Time and Actual Departure Time
  3. Under Origin Airport I chose San Francisco
  4. Under Airline I choose United and Delta
  5. Under Months and Days I chose All
  6. Under Years I selected 2008 and forward

I would of selected all years, however, the resulting dataset was too large and I kept getting IIS application errors when exporting to Excel/CSV. Additionally, while I chose 2017, I left this out of my analysis since reporting is not complete for this year.

I then did the Excel thing and created a few new columns to create and capture the summary data required.

First, lets look at the total Minutes Delayed by Year for flight departing SFO on United and Delta.

Just by looking at this we can see United and Delta have pretty hefty delays per year out of SFO. The scale of this graph starts at 100,000 minutes. 100,000 minutes is 1,667 hours which equates to 69 days. Clearly it seems United is straight up awful compared to Delta at SFO. However, as we know SFO is a pretty large hub for United and not for Delta.  Regardless of Delta’s delays, its still pretty awful that United has 766,975 minutes (532 hours) of delays in 2016.

I wanted to even the scales a bit since United has a much larger operation out of SFO. One way to do this is get the average minutes delayed by flight. The first step to breaking down the average delay per flight was getting the total number of departures from SFO per airline.

We can see how massive of an operation United has at SFO. Additionally, SFO isn’t even United largest hub. Depending on the metrics you use that falls to either Houston (IAH) or Chicago (ORD).

I then divided the total minutes of delay per year by the total flights in that same year for both United and Delta.

With the exception of 2010, United averages more delays per flight than Delta at SFO. Just to add some additional perspective, in 2016 United averaged a 14 minute delay per flight. Why the per in italics? Thats because United has 53,609 flights in 2016.


Just for additional clarity and full transparency on my delay numbers, I used the difference between the actual push back and scheduled push back. Therefore, I used every minute of the delay, starting at 1 minute. Many airlines don’t count delays unless its greater than 15. Additionally, the above metrics do not include United Express and Delta Connection. Technically, those are other airlines doing business as United Express or Delta Connection.

Survey Says

United needs to get their act together. While Delta isn’t running the finest option either from SFO, its definitely better than United overall. As the title of my post notes, Every Minute Counts.