Air travel has never been more global, yet some of the most obvious city pairs still have no non-stop flights. These gaps persist not because demand is weak, but because distance, aircraft performance, economics, and geopolitics still shape which routes airlines are willing to fly. Some of the world’s most heavily travelled long-haul flows remain entirely one-stop. Others, long ignored, have recently been connected for the first time — and often with immediate success.“Unserved” does not mean “unused”. Many of these city pairs move hundreds of passengers a day via Doha, Dubai, Istanbul, London, Singapore, or Los Angeles. What they lack is a nonstop operation that can be sustained year-round at a commercially acceptable margin. In some cases, the aircraft exist but the risk appetite does not. In others, geopolitical realities or bilateral restrictions make the route impossible. And in many cases, the demand exists but is too fragmented across seasons to support a single ultralong-haul aircraft tied up for 16-18 hours.One of the clearest examples is Cairo–Los Angeles. Egypt and the United States have strong tourism flows, a sizeable diaspora, and rising business links. Yet there is still no nonstop between Cairo and LAX. Passengers instead travel through Europe or the Gulf on itineraries that stretch to 18 hours or more. The issue is not the absence of passengers, but the absence of year-round premium demand that could support the cost of deploying an A350 or 777 on such a long mission.London–Canberra is another intriguing gap. The UK and Australia have never been closer in aviation terms; Qantas now flies nonstop from London to Perth. Yet the national capital, Canberra, still has no direct link to London. Canberra’s runway length, altitude, and relatively modest local catchment limit its viability for an ultralong-haul operation. Sydney is nearby, and passengers overwhelmingly connect through there instead, making point-to-point Canberra a difficult commercial proposition.Asia to South America is full of large unserved flows. Tokyo–Lima is a prime example. The Japanese-Peruvian community is substantial, and trade between the two countries has grown. But the route is too far for current aircraft to operate nonstop without severe payload penalties. Travellers route through the United States or Mexico, adding hours to the trip.India also has significant long-haul gaps. São Paulo–Delhi stands out as one of the most important missing connections between two major emerging-market economies. The traffic exists, but it is fragmented across Europe, the Gulf, and Africa. No airline has yet found the right combination of aircraft, schedule, and connecting feed to justify the nonstop. Mumbai–Los Angeles is another example. Despite the strong commercial and cultural ties between India and the West Coast of the United States, the route remains unserved. It is within the range of the 777-200LR or A350-900, but ultralong-haul flights require consistently strong premium demand, and Indian carriers have historically focused on more established long-haul markets.In Southeast Asia, Jakarta–Los Angeles remains one of the most obvious missing nonstops. Indonesia is the region’s largest economy, and Los Angeles is a major gateway for Pacific Rim travel. Yet carriers still route passengers through Tokyo, Seoul, Taipei, or the Gulf because no airline has the right long-haul fleet mix or network structure to support a dedicated service.While some major gaps remain, the last decade has seen formerly unserved routes become commercially viable for the first time. Technology, network sophistication, and changing demand patterns have created new possibilities.New York–Auckland is perhaps the clearest example. For years, the route was dismissed as too far and too thin. Today, both Air New Zealand and Qantas operate it with modern long-range aircraft, supported by a combination of premium leisure traffic and strong connecting markets at both ends.Perth–London went through a similar evolution. The idea of a nonstop “Kangaroo Route” was discussed for decades, but only became feasible when Qantas deployed the 787-9 in a low-density configuration and invested in connecting flows via Perth. The route has become one of the airline’s most successful long-haul launches.Doha–Auckland, one of the world’s longest commercial flights, redefined what a Gulf hub could support. Qatar Airways connected New Zealand directly to a vast network spanning Europe, the Middle East, Africa, and South Asia. By aggregating multiple mid-sized flows rather than relying solely on point-to-point traffic, the airline turned a theoretical route into a consistent performer.Africa has also seen long-ignored routes return. Lagos–Washington Dulles sat unserved for years, with travellers connecting through Europe or the Middle East. United Airlines has now launched a nonstop service, demonstrating how a strong hub on the US side can make West Africa more accessible without a stop. Meanwhile, São Paulo–Johannesburg, withdrawn when South African Airways restructured, has been relaunched by LATAM, restoring a direct link between South America and southern Africa.These examples show how quickly the map can change once aircraft technology improves and an airline with the right network sees an opportunity. The A350, 787, and 777-200LR have opened possibilities that were once beyond reach. The next generation — including the A350-900ULR variants and long-range narrowbodies — will push the limits further.But the world’s unserved routes persist for reasons that technology alone cannot solve. Geography matters. Ultralong-haul flights tie up expensive aircraft for long periods, magnifying the financial impact of any delay or operational disruption. Demand profiles matter too. Many of the world’s largest indirect markets have strong economy-class flows but weaker year-round premium yields, which makes nonstop service unviable. And geopolitics can be decisive; airspace restrictions in Russia or parts of the Middle East add hours of flying time and alter the economics of east–west long-hauls.Many of today’s major unserved routes will eventually launch as aircraft improve and markets mature. Others may remain one-stop indefinitely, not because of a lack of desire from travellers, but because even the most advanced aircraft cannot change the underlying economics of global aviation.The author is an aviation analyst. X handle: @AlexInAir.
