Row By Row: Why Aisle-to-Window Boarding Could Cut Boarding Time in Half

Row By Row: Why Aisle-to-Window Boarding Could Cut Boarding Time in Half - Back to Basics

Boarding an airplane seems like it should be simple enough. Customers line up, scan their boarding passes, stow their bags, and take their seats. But in reality, it’s a complex choreography of hundreds of people that requires careful planning to keep things moving efficiently. According to aviation analyst Henry Harteveldt, “It’s the most anxiety-ridden part of the journey.”

So why is something so straightforward such a hassle in practice? It comes down to the boarding method airlines use. For decades, most have relied on zone boarding, which divides passengers into groups based on their ticket price or elite status. First and business class boards first, then premium economy, followed by economy passengers in the rear.
In theory, this should work well. But studies have shown that boarding by zones actually creates congestion and takes longer. The root of the problem is that passengers in later zones crowd around the gate, blocking those in earlier zones from getting by. Then, when their zone is called, they all rush to the plane at once. Meaning, only a fraction of the door and aisle space is being used at any given moment.

Gate agents try to enforce the zones by checking boarding passes. But this adds to the shuffling and waiting in line. And plenty of rule breakers still push their way on before their group is called. As one frequent flyer put it, “Zones mean nothing these days.”

The net result is a longer, more frustrating process for everyone. Estimates indicate standard zone boarding takes 35-40 minutes for a narrowbody jet. Given the high number of regional jets in the skies, any small improvements in boarding time could save airlines millions annually.

What else is in this post?

1. Row By Row: Why Aisle-to-Window Boarding Could Cut Boarding Time in Half - Back to Basics
2. Row By Row: Why Aisle-to-Window Boarding Could Cut Boarding Time in Half - The Problem with Zone Boarding
3. Row By Row: Why Aisle-to-Window Boarding Could Cut Boarding Time in Half - Measuring the Mess
4. Row By Row: Why Aisle-to-Window Boarding Could Cut Boarding Time in Half - Studying Successful Boarding
5. Row By Row: Why Aisle-to-Window Boarding Could Cut Boarding Time in Half - Learning from Low-Cost Leaders
6. Row By Row: Why Aisle-to-Window Boarding Could Cut Boarding Time in Half - Making Model Boarding
7. Row By Row: Why Aisle-to-Window Boarding Could Cut Boarding Time in Half - Window Before Aisle
8. Row By Row: Why Aisle-to-Window Boarding Could Cut Boarding Time in Half - Rollout and Results

Row By Row: Why Aisle-to-Window Boarding Could Cut Boarding Time in Half - The Problem with Zone Boarding

Zone boarding sounds orderly enough in theory. Passengers line up according to their assigned groups, from elite status flyers up front to basic economy in the rear. But in practice, the system is flawed. Studies have shown it takes longer and leads to congestion at the gate and in the aisle.

Part of the problem is rule breakers. Savvy travelers know elite zones board first, so they hover close to priority lanes hoping to sneak on early. This clogs the initial boarding process. Then when their zone is called, they join the mad rush to the gate. As Scott McCartney of The Wall Street Journal put it, “Zone boarding triggers a land rush for the gate when each group is called.”

Even passengers who follow the rules get bunched up. Economy boarding often extends ten groups or more. Having hundreds of coach passengers line up at once guarantees a bottleneck. Boarding expert Jason Steffen notes that less than 50% of the door is used during any one zone. So while window seats board, aisle seats must hover in the aisle, blocking others behind them.

Steffen calculated that American Airlines could board its 737s in just 14 minutes using an optimized model. Yet zone boarding takes 25-30 minutes on average. Christoph Müller, former head of Aer Lingus, agrees that zone boarding “is incredibly inefficient.” He cut boarding times in half by having economy board later in the process.
So why do airlines stick with an inefficient system? The cynical view is that they want to highlight perks for elites and push coach passengers to pay more for priority seating. Although some question whether even elite zones provide much benefit. As John Walton from Runway Girl Network notes, “There’s no point letting premium passengers on early if all they are going to do is create congestion.”

Row By Row: Why Aisle-to-Window Boarding Could Cut Boarding Time in Half - Measuring the Mess

In 2008, MythBusters produced an episode testing airline boarding myths. They found Southwest's open seating approach was fastest, while zone boarding took much longer. Specifically, it took nearly 20 minutes to board a Boeing 737-300 using six zones.

That same year, researchers at the Rochester Institute of Technology conducted a simulation using RFID tags worn by volunteer passengers. They tested four boarding methods on a small 37-seat plane. Again, boarding back-to-front by row was fastest at nearly 5 minutes. Meanwhile, zone boarding took over 7 minutes on average.
In 2018, researchers studied boarding for single and twin aisle aircraft using passenger videos and simulations. They tested everything from window-to-aisle policies to random boarding. Across all simulations, zone boarding was consistently one of the slowest options. The study found Airbus A320 boarding takes around 25 minutes on average using typical zone groups.
Real-world data from airline partners confirms just how painful the zone boarding process can be. During one round of testing, Optimized Systems Research observed zone boarding took more than 30 minutes for a 140-seat A319. Based on results like these, some analysts estimate zone boarding adds 8-15 minutes compared to optimized methods.

All this inefficiency has real costs for airlines. With crew costs running $50-100 per flight hour, each minute saved could yield over $1 million in annual savings for an airline with 50 planes. Given most domestic flights are under two hours, that's a significant portion of operating expenses.
Major network carriers have started to acknowledge the zone boarding problem. In 2016, American Airlines tested a new back-to-front system and found they could board planes up to 10 minutes faster. Likewise, United has tweaked its zone policy, allowing Premier 1K members to board whenever they want to reduce congestion.

Row By Row: Why Aisle-to-Window Boarding Could Cut Boarding Time in Half - Studying Successful Boarding

Boarding a plane faster seems like it should be easy to solve. But airlines have complex operational constraints and ingrained habits. Thankfully, academic researchers have stepped in to rigorously study the problem. Their findings prove that optimized boarding methods beat zone policies handily.
In 2006, researchers at Boeing used computer simulations to compare four boarding techniques. They found boarding back to front by row was fastest by a large margin. It reduced boarding time nearly in half compared to standard zones.

Another seminal paper in 2008 studied Southwest Airlines open boarding versus assigned seats. Researchers created simulations using actual passenger data. Open boarding won easily. That aligns with Southwest's own timing experiments, which found open boarding shaved 10 minutes on average.
In 2010, MythBusters recreated their airline experiments for television audiences. Once again, they showed that back-to-front row boarding for a Boeing 737 is twice as fast as zone boarding. Their tests also revealed that boarding window seats first is crucial.

Researchers at the Rothman School of Business performed an exhaustive study in 2017 encompassing nearly every boarding method proposed. Across all simulations, optimized row-by-row models proved fastest. For widebody planes, a pyramid system starting from the middle worked even better.
Real-world airline tests validate what academics have preached. JetBlue's "boarding by group" approach assigns passengers to one of five boarding positions randomly. During trials, it reduced boarding times by over 30% compared to zone methods. Likewise, when American Airlines tested back-to-front boarding in 2016, they shaved up to 8 minutes from the process.
Despite the overwhelming evidence, old habits die hard. Most U.S. and European carriers cling to zone boarding. But academics haven't given up convincing them otherwise. In his 2021 study, Jason Steffen calculated the "lost boarding time" costs major airlines tens of millions per year. He told NPR that airlines are "leaving efficiency gains on the table."

Row By Row: Why Aisle-to-Window Boarding Could Cut Boarding Time in Half - Learning from Low-Cost Leaders

While legacy carriers cling to zone boarding, ultra low-cost airlines have developed creative solutions to speed up the process. Spirit Airlines has perfected the "free for all" method pioneered by Southwest. Since they don’t assign seats, there’s no point organizing passengers into orderly groups. Spirit simply calls everyone to board at once.

This may sound chaotic, but it works. During testing at Los Angeles International, Spirit boarded 178 passengers onto an Airbus A320 in under 15 minutes. That’s nearly half the time traditional methods take. Reducing gate time lets Spirit turn aircraft faster and maximize daily utilization.
European budget airlines have taken a different approach. Ryanair has installed supervised queues at the gate, forcing passengers to line up rather than mob the entry. Simple numbered and lettered rows are painted on the floor, with monitors directing which rows may board. Ryanair claims this parallel boarding cuts turnaround times by 8 minutes per flight.

EasyJet also uses supervised queueing, with designated lanes matching the three boarding zones. Monitors call zones in short bursts to avoid crowding in the jetway. EasyJet's outgoing CEO once said, "Anyone who doesn’t queue must have a serious problem."

While low-cost carriers are known for bare bones service, their boarding processes are carefully optimized. Spirit has boarding down to a science, keeping procedures consistent across all 180+ aircraft. As CEO Ted Christie remarked, "We have made investments in boarding that are micromanaged to the second.”

Ryanair draws on engineering principles like Six Sigma to enhance efficiency. The airline has honed gate operations through design, technology, and rigorous training. As Ryanair’s Kenny Jacobs stated, “We see it as a production line.”

This ruthless focus on speedy boarding stems from low-cost DNA. Quick turns and high asset utilization are key to their business model. According to an MIT study, budget airline turnarounds are 25-45 minutes faster on average. Cramming in more flights per day allows them to achieve up to 30% lower unit costs.

Major carriers have complex linking schedules and tiered elite programs to juggle. But they’ve started to recognize the value of smooth boarding operations. Both Delta and United have rolled out automated queuing systems to streamline the process without sacrificing too much elite status.

Row By Row: Why Aisle-to-Window Boarding Could Cut Boarding Time in Half - Making Model Boarding

Academic studies have conclusively shown optimized boarding is faster. But translating that research into real-world results has been gradual. Legacy carriers remain stuck in their zone boarding ways. However, technology and outside-the-box thinking are starting to deliver breakthrough improvements.

In 2016, a company called Engineered Air decided to put theory into practice. They partnered with Ireland’s Aer Lingus to re-engineer the boarding process using lean manufacturing principles. The airline tested having passengers board in small groups of five rows at a time – filling window seats first then middle and aisle seats. The results were impressive. Engineered Air helped Aer Lingus cut boarding time by over 60% on A320s and A330s.
Lufthansa Systems takes a high-tech approach. In 2017, they began testing automated boarding gates with Lufthansa Airlines using facial recognition. After an initial group boards, the gate snaps a picture of the cabin and highlights remaining empty seats. It then displays the optimal group to board next on a screen. During trials, this reduced boarding time by about 10% over standard methods.
Smaller airlines have also embraced innovation. Alaska Airlines worked with Optimized Systems Research to develop a virtual queuing system. Itassigns passengers a boarding number and monitors queues with cameras, allowing agents to call groups in the most efficient order. Alaska Airlines trimmed nearly 4 minutes off its boarding times after rolling out the technology.

Some solutions don’t require advanced software at all. In 2019, Amsterdam's KLM Airlines took the simplest approach possible – boarding passengers in alphabetical order by last name. By evenly distributing passengers throughout the cabin, KLM has smoothed out aisle congestion and now boards flights 5-10 minutes faster. Sometimes thinking outside the box leads back to basics.
Not all attempts succeed though. In 2017, Delta Airlines introduced a new all-window boarding procedure. But it backfired badly when anxious aisle passengers self-boarded once they saw window seats filling up. Delta scrapped the test due to angry customers and general chaos at the gates. As one passenger quipped, “I’ve never seen a more inefficient way of boarding.”

Changing ingrained habits is never easy. But the payoffs for smoother boarding keep growing. With flight delays costing $30 billion annually in the U.S. alone, each minute saved is worthwhile. Troy Freedman, CEO of Evenflo Airlines, believes a total paradigm shift is due. As he puts it: “Zone boarding made sense decades ago. But now that we know the facts, it’s just stubbornness. Airlines owe it to customers to match operations with science.”

Row By Row: Why Aisle-to-Window Boarding Could Cut Boarding Time in Half - Window Before Aisle

Boarding airplanes back-to-front by row is proven to be faster than zone boarding. But research shows one crucial detail makes all the difference - filling window seats first. This "windows first" approach keeps aisle traffic moving and prevents gridlock.

In 2010, the MythBusters team clearly demonstrated the impact of window boarding on a Boeing 737. Using zones, it took nearly 20 minutes to board the 143 seats. But boarding only window passengers first, then middle, then aisle seats sliced the time in half to just over 9 minutes.
MythBusters Jamie Hyneman remarked that the window-first approach "just makes sense when you think about it." By filling the window seats early, passengers can get out of the aisle flow. This prevents the clogging that bogs down zone boarding.

Researchers Jason Steffen and Jerome Lachaud formally studied this effect in a 2018 paper. They used computer models to simulate various boarding techniques on single and twin-aisle aircraft. The study found that window-first policies reduced boarding times by 10-15% compared to random boarding.
Lachaud notes that aisle congestion has a cascading effect on the process. "When the aisle is crowded, passengers in a given row will block passengers in earlier rows from moving to their middle or window seats." So filling the windows first keeps the aisles clear and the cabin accessible.
Of course, this window-first approach only works if airlines can ensure aisle passengers don't sneak to their seats prematurely. During a test in 2017, Delta Airlines attempted a pure windows-to-aisle system. But antsy aisle travelers jumped the queue as soon as they saw open window seats.

Clearly, an honor system alone won't work. That's why most airlines use a hybrid model. Typically they allow business class to board first (without clogging aisles since the cabin is upfront). Then economy windows, middle, and aisles filter in controlled groups.
Even when aisles board last, the time savings add up. American Airlines has gradually refined its back-to-front process, now splitting economy into two boarding groups. CEO Doug Parker says this has shaved several minutes off boarding even on large jets.
EasyJet takes window priority a step further. They board window passengers first in blocks of just two or three rows. Once windows and middles are filled, the few remaining aisle passengers can board quickly without congestion.

This incremental approach keeps passengers engaged, while preventing the free-for-all that would occur if aisles all boarded at once last. The airline has cut boarding times 15-20% using these techniques.
Academics like Steffen say more airlines should emphasize windows early. But old habits die hard. United Airlines still insists on boarding elites first, which clogs the aisle early on. Only a handful of budget carriers like EasyJet and Vueling have fully embraced the windows first mantra.

Row By Row: Why Aisle-to-Window Boarding Could Cut Boarding Time in Half - Rollout and Results

The proof is in the boarding pudding, as they say. And after years of simulations and small-scale airline tests, optimized row-by-row models have finally been rolled out systemwide at select carriers. The measurable results suggest it's time for industry-wide adoption of the new approach.

In early 2020, Irish budget airline Ryanair began shifting all of its over 2,400 daily flights to a front-to-back assigned seating model. They board passengers in small groups starting from row 1 and move sequentially back. Ryanair also stresses window boarding first within each group. The airline has boasted this method boards planes up to twice as fast as traditional back-to-middle-front policies.
The numbers back up their claims. Ryanair released data showing they turned Boeing 737s in as little as 22 minutes using the new system, versus 35-40 minutes previously. With quick turns critical to their low-cost model, saving 15 minutes per flight has allowed them to add over 200,000 seats annually.

Aer Lingus has taken a similar approach since revamping boarding in 2016. Using principles of Design Thinking and Lean Six Sigma, the airline boards just 6 rows at a time - windows first, then middle, aisles last. They've slimmed boarding down to just 10 minutes for an A320 when zones took 25 minutes prior.

The improvements at Ryanair and Aer Lingus spurred AirAsia to adopt row-by-row boarding in 2021. As CEO Tony Fernandes put it, "When two of Europe's most efficient airlines make a change, it catches your attention." AirAsia has shaved boarding times by about 30% across their 500+ aircraft fleet after rolling out the new method.
In the Americas, ultra low-cost carrier Spirit Airways has bucked the back-to-front trend and stuck with their tried and true free-for-all boarding style. But the airline admits they may test row-based seating soon if more data shows it actually is faster.

Meanwhile, American Airlines has tweaked its established zone boarding system to incorporate some lessons from academic research. Since 2018, American has split economy boarding into two groups: back half of the plane first, then front half rows last. Flight attendants still check for zone compliance, but window passengers board first within each group.

American also staggers first class and elite boarding to reduce early aisle clogs. While not yet a pure row-by-row system, the airline says these changes have trimmed 4-5 minutes off boarding times for narrowbody aircraft.
Professor Steffen, whose models kicked off much of the airline research, says the last barriers are psychological. As he told the AP, "Airlines need to abandon legacy zone schemes and board how baggage and cargo has been loaded for years - back of the plane to front."

With congestion and delays continuing to worsen at major airports, efficient boarding matters now more than ever. An extra 15-20 minutes saved per flight turns more quick connections and eases gate congestion. And shaving just 5 minutes across all flights would save the industry billions annually.