When Delta Air Lines adjusted the schedule of a plane’s time at the gate to give passengers five more minutes to board, the change measurably reduced flight delays, according to new research.
The study in Production and Operations Management analyzed two changes Delta made on June 2, 2022: First, it extended the scheduled boarding time for all domestic narrow-body flights from 35 minutes to 40 minutes by reallocating time used for other tasks while a plane is at the gate, such as deplaning, cleaning, refueling, or baggage handling. That same day, it also became the first US airline to pay flight attendants for boarding, at 50% of their regular hourly rate.
The researchers found that the extra boarding time worked: Flights left about 1.5 minutes sooner and the chance of leaving on time went up by about one-third. However, the researchers found no empirical evidence that additional pay for flight attendants reduced departure delays.
“Flight attendants already have strong incentives to depart on time, including point-based reliability policies and on-time bonuses, leaving little room for pay to speed things up,” says study coauthor Milind Sohoni, chair and professor of operations management and strategy in the University at Buffalo School of Management.
“That’s why it’s important for airlines to find the most impactful areas to adjust and increase efficiency. Padding schedules with extra time everywhere just to avoid delays is wasteful.”
To measure the impact of these two policy changes, the researchers used statistical methods that compared Delta’s narrow-body flights, which got both changes, with its wide-body flights, which got only the pay change. They also compared Delta against American and United Airlines using federal on-time data for April through July 2022, covering roughly 622,000 flights.
Their findings show that giving passengers an extra five minutes to get on the plane works because boarding is the last step before a plane leaves the gate, so any overrun directly delays departure.
The benefit was largest for flights departing later in the day (since delays tend to build as the day goes on), flights on busier routes and longer flights. For example, the reduction grew from about 0.8 minutes for morning flights to about 2.4 minutes for night flights. And on the busiest 10% of routes, delays fell by about 2.1 minutes, compared with 1.5 minutes elsewhere.
And while the pay policy change showed no detectable effect on delays, the authors note that it still has value for crew morale, retention, and fair compensation.
“Federal estimates show that delays cost airlines, passengers and the economy $33 billion per year,” says Sohoni. “Delta’s boarding change saves the company about $11 million per month in operating costs, plus about $12.5 million a month in passengers’ time. The cost of paying flight attendants for boarding is about $5.4 million a month, so the two policies together came out financially ahead.”
Additional researchers who collaborated on the study are from the Michigan State University Broad College of Business and the University of Arkansas Sam M. Walton College of Business.
Source: University at Buffalo
