Pacific crossings, if flown directly, often offer few straightforward refueling points and minimal options for quick diversions. If planes cannot easily refuel or quickly divert, are such routes safe, or even possible?
The use of such routings depends heavily on the aircraft used and on the exact starting point and destination in question, and it has changed over time with new technology and regulations. Large jets built for long-haul flights can and do make frequent trips over large swaths of open ocean, but even smaller, shorter-range planes can make route adjustments and utilize modified equipment to make trans-Pacific flights possible.
Did Aircraft Fly Over the Pacific Ocean in the Past?
The first successful transpacific flight took place in 1928. Four airmen ventured from Oakland, California, to Brisbane, Australia in a single-engine, propeller-driven Fokker FVII. The trip took around 82 hours traveling at roughly 85 mph, and involved three legs, with stops for fuel and rest in Hawaii and Fiji.
Most transpacific flights before the advent of modern long-haul jets utilized similar routing, often with one or more stops in the Pacific islands, Hawaii, or, for more northerly routes, in Anchorage, Alaska.
The earliest commercial transpacific flights, for example, were operated by Pan American Airlines’ “China Clipper.” The 8,000-mile voyages between Alameda, California, and Canton, China, were completed by a Martin M-130 with stops along the way in Oahu, Midway Island, Wake Island, Guam, and the Philippines.
These early flights required breaking the trip up into multiple legs for several reasons. Especially before the dawn of the jet age, these flights were slow and long. Technical restraints aside, nonstop transpacific flights simply took longer than was practical, as crews and passengers needed to rest.
Even if non-stop service was desirable in the early days, technical constraints made virtually any nonstop transpacific commercial flight impractical, if not impossible. The first nonstop trip took place in 1931, for instance, but the aircraft was so heavily modified that it had no room for passengers or cargo and even had its landing gear removed to save weight, requiring the pilot to crash-land upon completing the flight.
Why Do Some Flights Not Fly Over the Pacific Ocean?
Given the constraints of early transpacific flights, it was desirable, when possible, to avoid flying over lengthy stretches of ocean and to stay close to land. In many cases, especially between northern, central, and eastern North America and much of Asia, such routes are actually much faster than crossing the Pacific itself – even today.
The most direct route for a flight from Seattle to Beijing, for example, would involve very little flight over the Pacific Ocean itself. Rather, the most direct route would hug the western Canadian coast, Alaska, and far eastern Russia, before flying over the Chinese mainland.
Why not fly a straight line across the Pacific, one might ask?
The route appears to curve, but keep in mind that the above route is plotted on a flat map. When considering the best routing, pilots and dispatchers take the curvature of the earth into account. Looking at the earth as a globe, one can see that the route is actually a straight line. Of course, such a flight as that above would most likely look different today in practice, given current restrictions on Russian airspace.
Nevertheless, the routes shown in the two images above are actually the same route, just viewed first on a flat map, and second on a round globe. This concept of finding the most direct route – taking the earth’s curvature into consideration – is known as “great circle distance,” and as shown above, this can mean that transpacific flights may not always go directly over large portions of the Pacific.
This concept has made many transpacific flights much more attainable for much of aviation history, especially considering early technical constraints requiring stops, as well as later regulatory constraints.
The most significant regulatory constraints on transpacific routing came in the form of Extended-range Twin-engine Operational Performance Standards (ETOPS). The US Federal Aviation Administration and other international aviation regulators introduced ETOPS as a way to prevent twin-engine jets from flying too far away from diversion points in the event of the loss of one of their engines.
The earliest regulation, though not formally known as ETOPS, required twin-engine jets to fly within 60 minutes of a diversion point, although by 1985, examples of the Boeing 767 were certificated to fly within 120 minutes of diversion points.
These regulations limited the routes possible for many transpacific destinations that required flight over large areas of open ocean, leading many airlines to utilize airframes with three or four engines, like the Boeing 727 (trijet) or 747 (quad jet), in order to avoid ETOPS regulations.
In more recent years, ETOPS certifications have become available for longer periods of time. More recently, twinjets like the Airbus A350, for instance, have been rated for up to 370 minutes, opening the door for much more flexible routing, and drastically reducing airlines’ reliance on trijets and quad jets.
What Flights Fly Over the Pacific Ocean?
Although routes like the Seattle – Beijing route mentioned above will still route near land for the majority of the trip because such routing is the most direct, many flights are most efficiently served by a direct Pacific crossing.
Most flights between the Americas and Oceania involve flying directly over the Pacific. Direct flights between South America and Asia/Oceania would also traverse large swaths of ocean, although most of these routes involve connections in North America in practice.
Notable routes directly over the Pacific itself include Singapore Airlines’ routes between Singapore and Los Angeles/San Francisco (Singapore – San Francisco is also served by United Airlines), Qantas’ Sydney to Dallas route, and American Airlines’ service between Dallas and Auckland.
How Long Does It Take Aircraft to Cross the Pacific Ocean?
Transpacific flights are lengthy and include many of the world’s longest routes. Due to the route’s great circle distance, Singapore Airlines’ route between New York and Singapore does not fly directly over much of the Pacific, but it is the longest route in the world, at 18 hours and 30 minutes.
Comparatively short flights include JAL’s Los Angeles – Tokyo route, which lasts “only” 11 hours 40 minutes.
How Do Aircraft Communicate with the Ground While Crossing the Pacific Ocean?
Modern aviation relies primarily on satellite communications when crossing over the ocean, as most VHF radios tend to lose contact at altitude beyond about 200 miles from a receiver. In addition to voice communication, satellite coverage allows aircraft to automatically transmit their position, altitude, speed, identifiers, and more to controllers and to other aircraft.
Flights crossing the Pacific are increasingly common as technology and regulations allow for more flexible routing and as many Asian destinations continue their evolutions into ever-increasingly important global hubs. Most transpacific flights begin or end in North America, and many tend to stay close to land due to routing that considers the earth’s curvature.
Even so, some of the world’s longest routes are those that fly for hours over open ocean – routes that are safer and more common today than ever before.