MIAMI — Comparison research organization has unveiled its report on the ‘Least Reliable American Airports,’ based on a thorough study of the Bureau of Transportation’s 2017 records.The group has unveiled the worst performing airports—and airline—in the country, outlining the percentage of flights delayed out of major and minor airports (compared separately).

Los Angeles: The Bad

Topping the overall list is Los Angeles International Airport (LAX), with over 8% of flights departing at least 15 minutes late, followed by Atlanta Hartsfield-Jackson (ATL) with 7.8%, San Francisco (SFO) with 7.6%, Chicago O’Hare (ORD) with 7.2%, and Denver (DEN) with 5.4%.Top 5 major airport delays of 15 minutes or more

This list is relatively unsurprising; Los Angeles, Atlanta, Chicago, and Denver are all amongst the top four busiest American airports.

With increased passenger traffic (and thus, increased aircraft movements) inevitably comes increased delays, as aircraft congestion and missed connections begin to pile up.

These leaders are further supplemented by their positions as major connection hubs. All boast a wide array of short-haul domestic connections, operating as connection centers in their respective regions.

This places an increased vulnerability on departing flights as most are heavily dependent on a thick network of inbound aircraft.

“While flight delays can be frustrating, frequent flyers know they are an unavoidable factor of travel,” said Jennifer McDermott, Consumer Advocate for

“This analysis reveals you can hedge your bets when making a booking by erring away from the most unreliable airports if possible.”

According to the report, a delay at any smaller airport can quickly snowball into delays at the bigger ones, as demonstrated by the presence of SFO, LAX, ORD, and ATL in the top five in regards to delays caused by network interruptions.

TSA Playing A Role?

According to the report, security lines also play an important role in delaying flights.

“When it comes to security delays, Los Angeles International again takes top spot, responsible for 8% of all delays of this kind at major airports,” the report says.

At LAX, August is the worst moment for security screening.

“We sweat out these delays most often in the summertime too. It’s August that takes the lead with 11% of all security delays,” the report says.

Top 5 major airport delays due to security among major airports

Similarly, Los Angeles’ position as an international gateway (with substantially more international flights than any other airport in the top 5) further increases its own vulnerability to delays, as many outbound flights are dependent on the on-time arrival of inbound transpacific flights.

However, in terms of delays resulting from security, while LAX and ATL remain in the top five (as first and third, respectively), they are joined by Seattle/Tacoma (SEA) in second, Dallas/Fort Worth (DFW) in fourth, and Las Vegas McCarran (LAS) in fifth.

While Seattle, Dallas, and Las Vegas are all relatively large and busy airports, these statistics may be indicators of failures in their respective TSA systems and layouts.

The presence of frequent international departures in SEA and DFW may also contribute to this, as the necessity to undergo U.S. Customs may further slow passenger movement.

San Diego: The ‘Smallest’ Bad

America’s minor airports were led in unreliability with San Diego (SAN), showing 3.9% of flights out of this airport delayed.

“Those flying in or out of San Diego International Airport not only are more likely to experience flight delays of 15 minutes or more but also more likely to find themselves waiting due to air-carrier and national aviation system delays,” claims the report.

However, in terms of security delays, SAN is not the worst. “Alaska’s Ted Stevens Anchorage International Airport experienced the highest number of security delays, accounting for almost 11% of delays of this type,” notes the report.

In terms of delays, San Diego is followed by Dallas-Love Field (DAL), Tampa (TPA), Portland (PDX), and Houston-Hobby (HOU).

Top 5 minor airports with delays of 15 minutes or more

These delays are generally more related to weather events than are those of major airports, with many of these being especially vulnerable to thunderstorms (especially in the summer months).

These delays paint a broad picture of the patterns of delays throughout the most-traveled airports in America.

Weather Delays: Hello San Francisco!

Not surprisingly, the number-one spot for weather-related delays is in the San Francisco bay area.

“San Francisco International is the least punctual of all major airports when the elements outside take a turn for the worse, accounting for 8% of all flights delayed due to the weather,” says the report.

As far as minor airports are concerned, South Florida takes the win, mostly thanks to the year-round heavy thunderstorms and summertime hurricanes.

Tampa keeps the first spot, although by a small margin. “About 455 flights were delayed in Tampa due to weather — or 4% of all reported weather delays — closely followed by San Diego International, which saw 400 weather delays,” says the report.

The top 5 minor airports with weather delays

While delays are, for many flyers, a despised—albeit acknowledged—feature of many flights, it is clear that not all origins nor destinations are equal in terms of vulnerability to delays.

Travelers can expect frequent delays when connecting through major airports, in addition to locations featuring numerous international departures.

Avoiding unnecessarily short connections and booking flights arriving far in advance of any scheduled events may reduce the impacts of delays on travelers and provide security in the event of extensive delays.

The bad airlines

According to the report, “In 2017, about 1 in every 5 delays across major airports — 19% of all setbacks of 15 minutes or more — were attributed to American Airlines.

On a global scale, however, American had 22% of its flights delayed, system-wide. Southwest, Delta, and United follow, with 20%, 17%, and 11% respectively.

On a higher scale, American also ranked as the most delayed airline by security means, climbing to a whopping 29% of flights at major airports.

At smaller airports, though, Southwest is the first airline with most delays, with 35% of its flights leaving behind the schedule.

These numbers are indeed significant, as it shows that at major airports, American is facing lengthy delays because of congestion, security screening, connectivity, and weather.

Likewise, Southwest’s presence at minor airports in the US ranks them first in this segment of the market.