Jet lag can be one of the most annoying parts of flying long distances and is classified as a type of circadian rhythm sleep disorder. The Boeing 787 Dreamliner’s revolutionary cabin design helps passengers arrive relatively more refreshed and a little less jet-lagged. While the Boeing 787 is not unique in this regard, as most of the innovations are also found on the Airbus A350, it was the first airliner to offer this level of passenger comfort.

Jet lag is something that affects older passengers (particularly those over 60) more. It is a modern phenomenon, as older modes of transport, like sailing or even airships, were slow enough to give passengers time to adjust. Airplane makers may not be able to fix the underlying issue, but they have come up with ingenious ways to reduce the effects. The Boeing 787 first entered service in 2011, and it offered a range of innovations to increase passenger comfort and decrease jet lag.

Jet Lag Is A Behavioral Sleep Disorder

Jet lag is a behavioral sleep disorder caused by a disagreement between the actual time zone one finds oneself in and the body’s « internal clock, » aka circadian rhythm. Flying across time zones disrupts people’s sleep patterns and their circadian rhythm. Some people require a few days to recover, sometimes as much as a week.

But there is much more to jet lag than just crossing time zones too quickly. For example, medical experts generally agree that flying eastwards can cause more severe jet lag than flying westwards. So a passenger flying from the US to Europe may be expected to experience more jet lag than a passenger flying from Europe to the United States. Another factor is age. Children typically have no problems with adapting to a new time zone.

There is nothing engineers can do about the time zones or the east/west factor, but there are other factors where airplane engineers can help reduce the impact of jag lag. This is because a range of issues, from air pressure to humidity, to lighting, to fluid intake, and more, can all play a part in influencing jet lag.

Increased Cabin Pressure

Passenger airlines can fly as high as 40,000 feet. This is well above the « death zone » mountaineers face when ascending Mount Everest. The death zone is above 26,000 feet. At 40,000 feet, there is not enough oxygen, and people would black out and eventually die from a lack of oxygen. And so aircraft cabins are pressurized. However, there is a trade-off as pressurization increases stress on the fuselage and wears out the aircraft.

The industry standard has been to pressurize cabins to 8,000 feet, or around the same altitude as Aspen, Colorado (7,900 feet). This is tolerable for older aluminum fuselages, while being acceptable for most passengers. Going much higher than 8,000 feet can cause altitude sickness, called hypoxia. But the Boeing 787 is not primarily constructed out of aluminum; its extensive use of advanced materials allows the cabin to be pressurized to 6,000 feet (the same for the A350).

Jet lag is aggravated by the body being fatigued. By pressurizing the cabin more, passengers will feel less fatigue, and this can help ease symptoms associated with jet lag. The industry has come a long way. The first commercial cabin pressurization system came into use in 1946. Honeywell says, « Boeing’s 307 Stratoliner – nicknamed the Flying Whale – began flying passengers in pressurized comfort at 20,000 feet. It was the first in-service pressurized airplane and airliner in history. »

Better Lighting To Mimic Day/Night Cycles

As jet lag is a sleep disorder, anything that can help passengers sleep at the right times and adjust to the changing time zones can help with jet lag symptoms. Even the large, dimmable windows can play a role. The airline is able to dim these windows to encourage passengers to get the sleep and rest that they need during the best phase of the flight. These are technologies found on other modernized airliners, including Airbus aircraft. Even current production models of the Airbus A350 feature dimmable windows.

Another feature is the Boeing 787’s LED cabin lighting system. These are able to simulate sunrise and sunset and help sync passengers with the aircraft’s destination’s time zone. In other words, the Boeing 787 can begin the work of adjusting people to the change of time zones before passengers even get there. The LED system is designed to reduce fatigue and keep passengers refreshed on long-haul flights.

The lights are designed to mimic the sun’s progression. They gradually shift from warm sunrise colors to cool midday blue, then to sunset oranges and deep blues. The intent is to reduce the jarring effects of time zone changes. When traveling east, lights may speed up the body clock by exposing passengers to light earlier. When traveling west, they light up during the evening hours.

Increased Cabin Humidity In Boeing 787s

Another factor is that the Boeing 787 boasts increased cabin humidity compared with previous-generation aircraft. Again, this is more of a generational factor, and not a Boeing vs Airbus factor. The clean-sheet A350 also has higher cabin pressure. Low humidity can cause passengers to have dry noses, dry eyes, and a sore and parched throat after long flights.

The Boeing 787 increases the cabin humidity from the previous 4-7% on older aircraft to 15-25%. Again, this is thanks to its corrosion-resistant composite materials that also allow higher cabin pressure. There are other improvements as well, including advanced filtration that can lead to fewer headaches. Unlike the traditional Boeing 777 and its Airbus A350 competitor, which use bleed air to pressurize the cabin, the 787 draws fresh air directly from outside the aircraft through two dedicated inlets.

Airbus says « improved humidity levels [on the A350] during cruise – leading to less overall passenger fatigue. » Dry noses and eyes don’t, of themselves, cause jet lag, but the overall discomfort can interrupt sleep and aggravate jet lag. Better relaxed passengers tend to have reduced jet lag symptoms. Even flying in premium economy or business class could help, as passengers should be better able to relax and sleep.

Noise Improvements Helping Reduce Jet Lag

The Boeing 787 Dreamliner is designed with various other improvements that can aid in reducing jet lag to some extent. The 787 is significantly quieter than older jets and is sometimes said to be as much as 60% quieter from the outside. This is thanks to a range of design innovations, from the larger engines with greater bypass ratios, to chervons on the engines, to more advanced sound-absorbing linings, to its composite fuselage that dampens the vibrations.

People can generally relax and sleep better in a quieter environment, although this varies from person to person. Boeing says, « more attention has been paid to the level and quality of noise within the 787 cabin because noise can contribute to a passenger’s sense of fatigue. » In the cabin, the 787 Dreamliner is around 20% quieter than older aircraft models.

The aircraft comes with technology and advanced aerodynamics that minimize the bumps from turbulence that people feel during flight. This can help prevent passengers from being jolted awake, enabling them to get their sleep. While stretching the jet-lag relevance a little, the Dreamliner’s interior is also designed with a more inviting open architecture to create a sense of space and increased roominess for passengers to relax.

Passengers Can Also Take Steps To Reduce Jet Lag

All this cannot ensure passengers will not get jet lag, but they do represent efforts by Boeing to do what it can to mitigate the effects. There are some things passengers can also do to reduce the effects. Cleveland Clinic says, « Unfortunately, there’s no way to prevent jet lag completely. No prevention strategy can guarantee you won’t experience the condition. But many steps can help minimize jet lag’s potential impact on you. »

To reduce jet lag, the clinic suggests keeping the body moving during the flight and moving about the cabin when possible. Another tip is to go to bed later and wake up later for several days before an east-to-west flight and the reverse for a west-to-east flight. Some of the most common suggestions are to drink plenty of water and to avoid drinking too much caffeine or alcohol on the flight. Caffeine and alcohol are known to make jet lag worse. Those who can afford it can consider purchasing higher-class seats.

Flying has come a long way from the first aircraft. Once upon a time, cabins were considered comfortable if they were pressurized to 20,000 feet, an altitude that would give many people altitude sickness. Going back further, the cabin on the Graf Zeppelin airship wasn’t even heated, so passengers had to wear their winter coats. Today, the Boeing 787 Dreamliner offers some of the best comfort for passengers at 40,000 feet and has been designed to mitigate passenger jet lag where possible.