Among U.S. airlines, American Airlines finished last in on-time arrival performance in June, a poor ranking for a carrier that has emphasized running a reliable operation.

Only 72.4 percent of American’s flights reached the gate within 14 minutes of their scheduled arrival time, putting American behind not only United Airlines, Delta Air Lines and Southwest Airlines, but also ultra low cost carriers Spirit Airlines and Frontier Airlines. The U.S. Department of Transportation measures the on-time performance of a dozen of the nation’s largest carriers, a group that includes regional airlines SkyWest Airlines and ExpressJet, but does not include Allegiant Air.

American said it is facing several challenges, including integration issues related to its merger with US Airways, poor weather in some of its hubs and challenges in Los Angeles, where it has tried to add flights despite considerable space constraints.

Post-Merger Woes

Structurally, American is less organized than other U.S. airlines because it still has not fully merged the two computer systems it uses to manage its operations.

To improve, American is trying to build a new Flight Operating System, a network of 500 different applications that will control the movement of all the airline’s aircraft and people. Today, it uses two distinct platforms — one that controls all former US Airways in-flight employees and aircraft, and the other that handles all former American people and planes.

Since American has two systems, pilots and flight attendants can only fly on aircraft that belonged to their airline before American and US Airways carriers merged. That keeps American from scheduling its crews in the most efficient manner.

“A single system will allow these groups to run the operation as one airline,” the airline said in an April employee newsletter. “American will be able to better optimize our crews and network by putting the right aircraft in the right markets.”

Merging the two systems will take about 1.8 million man hours of computer programming, and will cost about $280 million, American has said. The project should be completed by next year, though some elements will be done this fall.

“We are still operating two airlines from the perspective of crews,” American spokesman Ross Feintstein said Wednesday in an interview.

Problems in Los Angeles

American has also struggled in Los Angeles, where it is trying to build a trans-Pacific hub to rival United’s in San Francisco and Delta’s in Seattle, despite having access to relatively few gates at Los Angeles International Airport.

American added more than 20 new flights from Los Angeles in June, including new service to Auckland, New Zealand. It also hired hundreds of new employees, many without airline experience. In addition, American said its caterer had not been prepared for the onslaught of new work, which lead to delays.

American is reducing its schedule in Los Angeles this fall to try to improve its operation, and selected a second caterer to handle some international flights. Eventually, it hopes to add more gates at the airport.

“Despite many months of preparation and the LAX team’s incredible work, we have not been able to operate the significantly increased schedule up to our reliability standards,” American COO Robert Isom told employees in July.

Weather Issues

Elsewhere, American said summer storms have been problematic.

Feinstein said the airline’s hubs in Miami and Dallas/Fort Worth are unusually susceptible to thunderstorms. Sometimes, that means American must divert flights, as it did on August 12, when Feinstein said 78 flights scheduled to arrive at Dallas/Fort Worth were forced to land elsewhere. Other times, when lightning is observed near an airfield, as happens often in Miami during summer, American baggage handlers and other ground workers must take shelter inside, slowing the operation.

“Weather has not been our friend, especially in the hubs we operate in,” Feinstein said.

On-Time Can Be Expensive

As it tries to improve performance, American has said it will focus on what the government calls D:00, or flights that leave exactly on-time or early.

“The best way to arrive on-time is to depart on time,” Feinstein said.

Isom also recently told employees that American postponed some minor summer maintenance work for Boeing 737 interiors to ensure the airline would have more aircraft flying. Also, according to the airline’s pilot union, Americans pilots have also been asked to fly faster at times. 

Carriers have other options to improve their on-time numbers, but they are costly. Airlines seeking to improve performance can add more spare aircraft, increase the time they allot for each flight and build-in more ground time between flights.

Still, carriers sometimes find it necessary to take major action. United struggled with on-time performance so much last year that it added five minutes to its minimum aircraft ground times in late 2015 and another five minutes in Spring 2016, according to a source familiar with the airline’s operation. This means United planes are sitting at airports longer than in previous periods. But it also means fewer passengers are waiting for aircraft to arrive.

But the source said merely adding five minutes to aircraft ground time costs United about $35 million per year, because of decreased productivity. As a result, the source said, United has told employees it will roll back some of the costly initiatives it has used to improve its on-time numbers. United is seeking cheaper initiatives to drive on-time performance.

United CEO Oscar Munoz addressed this topic indirectly in July on the carrier’s second quarter earnings call.

“We are now consistently performing at the level that we and our customers expect of us,” he said. Our focus has now shifted to maintaining this level of reliability while doing so more efficiently.”

In June, United finished fifth in on-time arrivals, with 79.2 percent of flights arriving within 14 minutes of schedule. The top four carriers were Hawaiian Airlines (91.1 percent), Alaska Airlines (86.4 percent) and SkyWest Airlines (84.6 percent) and Delta Air Lines (83.4 percent). SkyWest operates as a feeder airline for American, Delta, United and Alaska.

Photo Credit: An American Airlines 737 taxis at Miami International Airport. American's Miami hub is susceptible to summer storms. Wilfredo Lee / Associated Press