Wake turbulence and wingtip vortices are invisible phenomena that sometimes appear in the form of white trails tracing and spiraling from wingtips. Pilotsalso try to visualize the wake of these airflow disruptions in heavy traffic to ensure they fly far enough away for the vortices of other planes in tighter patterns or formations. They study how vortices behave and dissipate to predict their movement and avoid catching wake turbulence.
Known as contrails, vortices create condensation trails when they remain suspended in the air at high altitudes. They move with the winds but often keep their shape. Pilots can observe the activity of the prevailing winds aloft and predict the vortices’ direction and rate of drift behind other aircraft’s flight path. Let’s dive into the details of these peculiar and often visually stunning natural phenomena of flight.
Wingtip Vortices: The Aerodynamics
Photo: US Air Force
An airfoil, or wing, gives an airplane lift, but it inevitably also induces drag. When a wing is positioned at a positive angle of attack, this means it is pointed up from the natural direction of straight on airflow. A pressure differential then exists between the upper and lower surfaces of the wing.
Air moves from high pressure to low pressure, and the path of least resistance is toward the wingtips, and a whirlpool of air called a ‘vortex’ occurs as air is dumped off the wingtips. Below are the main takeaways concerning this phenomenon, according to the online Pilot Institute:
Key Points
Wingtip vortices, not engine exhaust, create the strongest wake turbulence.
Heavier, slower aircraft in a clean configuration produce the most intense vortices.
Wake turbulence can cause severe roll and structural damage to smaller aircraft.
Pilots avoid vortices by maintaining safe separation and adjusting flight paths.
The air on the upper surface of the wing tends to flow in toward the fuselage and off the trailing edge, forming a similar vortex at the centerline of the plane. As the air curls upward around the wingtip, it combines with the wing’s downwash to form a fast-spinning trailing vortex. As the angle of attack increases, induced drag also increases, as there is a greater pressure difference between the top and bottom of the wing.
Maximum Vortex Power: A Critical Phase Of Flight
Photo: US Air Force
An airplane will create wingtip vortices with maximum strength during the takeoff, climb, and landing phases of flight. The intensity or strength of wingtip vortices is directly proportional to the weight of the airplane and opposite to the wingspan and speed of the airplane. When flying behind a large aircraft on the same route, pilots can adjust their course upwind to avoid getting caught in the wake.
As time passes and the vortices lose energy, they sink at a rate of several hundred feet per minute as they dissipate. If there is significant atmospheric turbulence around, it will help dissipate them faster. On calm days with still air, wake vortices will be hanging around for a longer period of time.
Close to the ground, wake vortices trail symmetrically behind an aircraft in calm wind conditions, often extending 3,000 feet behind. The vortex behavior changes within a couple of hundred feet of the ground. If generated by a large aircraft, such as a Boeing 747 or an Airbus A380, the vortices won’t have deteriorated entirely by the time they sink to the ground. As the swirling air strikes the ground, the vortex is pushed laterally along the surface, typically at a speed of two or three knots.
Aircraft Are Fitted With Winglets To Improve Their Fuel Economy
Photo: US Air Force
In 1897, British engineer Frederick W Lanchester began developing wing end-plates to reduce the impact of wingtip vortices. Lanchester laid the foundation for modern commercial technology, which was brought to its current state largely by NASA research in the 1970s. Per NASA, aeronautical engineer Richard Whitcomb conducted computer and wind tunnel tests to explore the hypothesis.
A precisely designed, vertical wingtip device, which Whitcomb dubbed a ‘winglet,’ proved to weaken wingtip vortices and thus diminish induced drag. Less drag would translate into less fuel burn and better cruise efficiency. The winglet concept provided a better option than longer wing extensions, which, while offering similar aerodynamic benefits, do not render a plane too wide for most airport gates.
Whitcomb’s findings in 1976 predicted that winglets employed on transport-size aircraft could diminish induced drag by approximately 20% and improve the overall aircraft lift-drag ratio by 6-9% as well. The Dryden test program results indicated to the entire aviation industry that winglets were a technology well worth its attention. Since that time, the technology has become a staple of commercial jet design.
Boeing Aerodynamics: 777X’s Folding Wingtip
Photo: Coby Wayne | Shutterstock
In direct contrast to the winglet design, the Boeing 777X uses 10 foot folding wingtips that extend the wingspan for better lift, lower drag, and improved fuel burn. These fold upward on the ground so the jet can use the same gates and taxiways as the preceding Boeing 777 aircraft. This design delivers greater range and lower operating costs than even winglets could achieve without requiring airports to modify their infrastructure.
Of course, that doesn’t mean that Boeing isn’t a fan of winglets. Indeed, in 1999, Aviation Partners Boeing was formed as a partnership between Seattle-based Aviation Partners Inc. and Boeing. The companies created APB initially to upgrade Boeing Business Jets, whose products include a VIP 737 derivative. Together, the pair would produce a unique take on the NASA-proven winglet technology: Blended Winglets.
APB’s Blended Winglet reduces drag and takes advantage of the energy from wingtip vortices, actually generating additional forward thrust. The design merges with the wing in a smooth, upturned curve to solve a key problem with more angular winglet designs: interference drag that occurs when two lifting surfaces intersect.
APB’s Blended Winglet technology is estimated to have saved several billion gallons of jet fuel worldwide, with monetary savings of $4 billion. That is equivalent to a reduction of almost 21.5 million tons in carbon dioxide emissions.
Sharklets: Airbus Aerospace Design
Photo: Airbus
Airbus Sharklets are also up-curved wingtip devices that cut wingtip vortices, and the European planemaker estimates that they trim induced drag by roughly 4% on its airliners. The lower drag lets aircraft burn less fuel, extend their range, or carry extra payload while also climbing more efficiently and reducing carbon emissions. Airbus has also offered a retrofit kit for in-service A320-family jets that were made before the widespread introduction to be able to gain the same advantages.
Today, Sharklet wingtip devices that increase aerodynamic efficiency are carried by every Airbus A320neo family jet. Combined with more efficient engines, Sharklets reduce fuel consumption by around 20% as compared to earlier-generation Airbus planes. The manufacturer also claims up to 30% better fuel burn compared to a non-winglet-equipped design in the case of the A321XLR.
Warbird Winglets For Fuel Savings
Photo: US Air Force
Having already tried winglets a decade ago, earlier this year, in July 2025, a US Air Force MC-130J Hercules took to the skies fitted with small aluminum fins on its rear cargo door and along both sides of its vertical tail. The Air Force says these aerodynamic ‘finlets’ could cut drag on Lockheed Martin C-130 airframes by 6-8%. This reduction would translate into longer range and improved fuel economy to improve mission capability and reduce operating costs for the global fleet
Per Air & Space Forces Magazine, Roberto Guerrero, the Deputy Assistant Secretary of the Air Force for Operational Energy, Safety & Occupational Health, said in a July 24 release from the 96th Test Wing at Eglin Air Force Base, Florida, that:
“It is an exciting day for the Department of the Air Force for finlets to reach this milestone in research, testing, and development as we seek to rapidly deploy innovative technology,. Drag reduction initiatives like finlets are a tangible way we can modernize our fleet, reduce costs, and increase combat capability for the warfighter. Every gallon of fuel saved extends our operational reach and enhances readiness in contested logistics environments, directly supporting the Department’s mission to deliver airpower anytime, anywhere.”
The Air Force has also explored winglets for the KC-135 Stratotanker to improve fuel efficiency on its aging tanker fleet. The winglets have been tested to use an Active Load Alleviation Control System (ALACS) to manage wing stress.
The Air Force requested $15 million for initial development and testing in 2024, with an additional $140 million planned between 2025 and 2028 for wider implementation. Although, based on recent reporting by Air & Space Forces Magazine, the winglets program may have been put on pause. The fiscal year 2026 budget request appeared to contain no mention of funding for the winglet upgrades, leaving its fate unclear.
The Boeing 787 Dreamliner (specifically the Boeing 787-9 variant) is currently the most popular widebody aircraft on the market. It was built to replace the Boeing 767, complement the Boeing 777, and compete with the Airbus A330 (now A330neo) and the A350 that entered service four years after the Dreamliner. It also helped to doom the Airbus A380 as well as the Boeing 747-8i.
Even though Boeing slashed production of the 787 during the pandemic by shutting the assembly line in Seattle, it is currently being delivered in higher numbers than other widebody aircraft. Boeing is also working to expand its production in North Charleston, South Carolina, and ramp up production. Here is what to know about the Boeing 787’s deliveries in 2025 and beyond.
The Number Of Boeing 787s Delivered By Mid-2025
Photo: eric1207cvb | Shutterstock
As of mid-2025, Boeing’s records show it has a total unfulfilled backlog of 993 Boeing 787s on order from a total of 2,199 firm orders. This has made the Boeing 787 the best-selling widebody aircraft in history. But while Boeing wins that accolade, Airbus’ A320 family is the best-selling commercial jet in history and is becoming the most delivered commercial jet.
When it comes to deliveries, Boeing has delivered 399 of its 787-8 variant Dreamliners, 681 of its mid-sized 787-9s, and 126 of the 787-10s. That is a total of 1,206 Boeing 787s delivered since the first example entered service in 2011. While the rival Airbus A350, which entered service in 2015, has proven to be a popular aircraft, the Dreamliner has continued to outperform it in both orders and deliveries. A total of 1,428 A350s have been ordered, of which 669 have been delivered.
Orders for the Dreamliner continue to roll in, and in 2025, Boeing has amassed a total of 243 new orders for its Dreamliners. These are thanks in large part to Qatar Airways, which ordered 120 new 787s, while British Airways and Korean Air have also placed substantial orders. All orders have been for its 787-9 and 787-10 variants, and none are for the 787-8.
Boeing’s Past Dreamliner Delivery Rate
Photo: Peter Krocka | Shutterstock
Before the pandemic, the Boeing 787 was delivered in much larger numbers. Boeing was building them in both Everett in Seattle, and in North Charleston. In 2019, the last “normal” production year for the Dreamliner, Boeing delivered a total of 158 aircraft. In 2020, that dropped to just 53 and to only 14 examples in 2021. In the pandemic, Boeing shut down its Seattle assembly line for the 787.
In 2022, deliveries recovered somewhat to 31 examples and grew to around half the prepandemic rate of 73 in 2023. 2024 was another bad year for Boeing deliveries, with its total deliveries falling back to just 348 commercial aircraft (Airbus delivered 766 that year). In 2024, Boeing delivered 51 Dreamliners, although it has delivered 45 by mid-year 2025.
Boeing 787 Dreamliner deliveries by year since 2019 (per Boeing)
2019
158
2024
51
2020
53
2025 (mid-year)
45
2021
14
2025 (estimated)
75-80
2022
31
Planned end of 2025 rate
84 (seven per month)
2023
73
Total delivered (mid-2025)
1,206
While 2019 was the last “normal” production year for the Dreamliner, 2018 was the last “normal” year for Boeing’s commercial aircraft overall. In 2019, the second Boeing 737 MAX crashed, and Boeing’s deliveries have not recovered since. From 2015-2017, Boeing delivered between 748 and 763 aircraft, rising to 806 in 2018. Since then, the most it has delivered was in 2023, when it shipped 528 aircraft.
At the start of 2025, Boeing projected deliveries of 75 to 80 Dreamliners in 2025. That number includes both new-build jets and those currently in inventory that it has been unable to deliver. At the start of 2025, Boeing had an estimated 25 Boeing 787s built in previous years but stored before delivery. If those jets are delivered, then Boeing’s 2025 production would be 50-55 new aircraft.
787 orders and deliveries per Boeing mid-2025
Boeing 787-8
Boeing 787-9
Boeing 787-10
Total
Total number ordered (per Boeing, may include orders later canceled)
In 2019, Boeing was delivering the Dreamliner at a rate of 14 per month; by the start of 2025, that was just five per month, with plans to increase it to seven per month. Even so, that is only half of the pre-pandemic levels. Part of the issue is that Boeing is trying to restore its world-class quality control to its aircraft to ensure things like the Boeing 737 MAX crashes and the Alaska Airlines door plug blowout don’t happen again.
Leeham News says that when the expansion is finished in 2028, Boeing will have the capacity to reach a rate of 16 per month. If Boeing could deliver the aircraft at a rate of 16 per month, that would translate to 192 aircraft a year.
Story Of The Boeing 787-8
Photo: Minh K Tran | Shutterstock
The Boeing 787-8 was the first to debut, and it attracted a large percentage of the orders. However, the 787-9 hit the market in 2014, and since then it has attracted more orders, with new orders for the Boeing 787-8 drying up over time. Boeing only has 28 orders for the 787-8 remaining on its order book, over half (15) of which are for Emirates.
Since 2020, Boeing has only recorded eight new orders for the 787-8 variant. This suggests that the Boeing 787-8 may soon go out of production. Increased Dreamliner production means more 787-9s and 787-10s and not 787-8s. One of the reasons why the 787-9 is more popular is that the wings are better optimized for that variant than the 787-8 or 787-10.
Boeing 787-8
Boeing 787-9
Boeing 787-10
Range
7,305 nautical miles
7,565 nautical miles
6,330 nautical miles
Typical 3-class seating
248
296
336
Length
186 feet
206 feet
224 feet
The 787-9 is the longest ranged variant with a range of 7,565 nautical miles, compared with the 787-8’s 7,305 nautical mile range and the 787-10’s reduced 6,330 nautical mile range. The 787-8 is being outcompeted by both the 787-9 and the cheaper-to-operate but still large and long-range Airbus A321XLR. The A321XLR comes with a range of 4,700 nautical miles.
Boeing 787 Dreamliner Production To Recover By 2028
Photo: Mehdi Photos | Shutterstock
After a decade-long dip in production due to the pandemic and lingering concerns with Boeing’s quality controls, the Dreamliner appears set to meet and even exceed its previous delivery rates around 2028. In 2025, the Dreamliner’s deliveries will remain around half that of pre-pandemic numbers but above that of 2024.
The 2025 final delivery rate will hinge to some degree on when Boeing can move the already-built Lufthansa Dreamliners and any others it has lying around. The future appears bright for the Dreamliner (except the 787-8) with large numbers of orders continuing to be placed and Boeing looking to restore its previously high levels of production. One of the major areas of uncertainty for the Dreamliner and Boeing aircraft in general is the ongoing trade war.
Both Boeing and Airbus are part of the supply chain integrity coalition, which aims to change how parts are tracked from the production line to the boneyard.
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The Airbus A330-800neo is one of two variants in the Airbus A330neo family, with the other being the A330-900neo. The A330neo is an upgrade over the original A330 variants, with new engines, updated wingtips, interior improvements, and software upgrades. The A330-900, directly succeeding the A330-300, has proven effective and has even found love in the United Statesat Delta Air Lines. Contrastingly, the A330-800 has been shunned in the US.
In some ways, you can consider the start of the A330neo to be the original A350 program. To compete against the Boeing 787, Airbus took the A330 family and added new engines along with a carbon-composite wing and a new cockpit. Airlines largely rejected the concept, prompting Airbus to create a clean-sheet aircraft, the A350 XWB, and move up in size. The A330neo was developed in the 2010s to slot underneath the A350 in price and capability.
The Airlines That Don’t Want The Airbus A330-800
Photo: Dirk Daniel Mann | Shutterstock
The A330-800 is Airbus’s smallest widebody, and given that the US is home to more Boeing 767s (a similarly-sized twinjet) than any other nation in the world, you’d expect the European manufacturer to make significant efforts to sell this jet here. However, Airbus hasn’t sold a single A330-800to a US airline. This is especially surprising considering that the prior A330-200 has been reasonably successful in the country, being operated by Delta, Hawaiian, and, previously, American Airlines.
United Airlines currently flies 53 aging Boeing 767s, but has committed to the 787 to replace these planes. Hawaiian Airlines, a current A330-200 operator, ordered Boeing 787-9s to replace its Airbus widebodies, although these planes are now slated to remain in service while the Dreamliners get transferred to Alaska Airlines. For American Airlines, meanwhile, its 767 and A330 fleets were fully retired during the COVID-19 pandemic, with the 787 serving as their replacement.
Only four airlines in the US operate passenger widebodies in scheduled service, and by and large, they have opted for the similarly sized Boeing 787. This is despite the fact that these planes are replacing the Boeing 767 or Airbus A330, which are optimized for medium-haul routes, similar to the Airbus A330neo. Notably, Hawaiian Airlines formerly held orders for six Airbus A330-800s, but cancelled them in favor of the Dreamliners.
Why Delta Air Lines Isn’t Buying Them
Photo: Minh K Tran | Shutterstock
Delta Air Lines is the largest operator of the Airbus A330-900 in the world and the largest operator of the A330 series as a whole. It operates 11 A330-200s, 31 A330-300s, and 37 A330-900s with two more on order, but has never ordered the A330-800, and has not announced plans to obtain more A330neos. What’s surprising is that the A330-900s were slated to partially replace the Boeing 767-300ER fleet, an aircraft significantly smaller than the A330-900.
You’d expect Delta to replace these aircraft with the A330-800, given that it would be far closer in size to the 767. However, going with the larger A330-900 instead was a conscious choice. Delta is looking to upgauge its entire network, replacing A320s and 737s with A321neos and 737 MAX 10s, while 767s are to be replaced with larger widebodies. Delta is looking to lower per-seat economics, and larger aircraft variants are cheaper to operate per-seat than smaller variants.
Aircraft Types In Service With Delta
Aircraft Types On Order By Delta
Airbus A220-100
Airbus A220-300
Airbus A220-300
Airbus A321neo
Airbus A319-100
Airbus A330-900
Airbus A320-200
Airbus A350-900
Airbus A321-200
Airbus A350-1000
Airbus A321neo
Boeing 737 MAX 10
Airbus A330-200
Airbus A330-300
Airbus A330-900
Airbus A350-900
Boeing 717-200
Boeing 737-800
Boeing 737-900ER
Boeing 757-200
Boeing 757-300
Boeing 767-300ER
Boeing 767-400ER
Delta only has two A330-900s left on order. It’s expected that at least part of its remaining A350 order will displace existing A330-900s that can replace the remaining 767-300ERs, which would again be a system-wide upgauge. Meanwhile, it’s been heavily speculated that the Atlanta-based carrier is looking to order Boeing 787-10s. With a possible delivery date in the early 2030s, these could replace older A330s and the Boeing 767-400ER, while also being a significant upgauge over both types.
Why The Airbus A330-800 Is Not Selling
Photo: Markus Mainka I Shutterstock
In the US, Delta is looking to upgauge its entire network, while other carriers are focusing on the Boeing 787. However, the A330-800 has also sold poorly around the world, with only eight total orders, while the A330-900 has received nearly 440. Seven have already been delivered: four to Kuwait Airways, two to Uganda Airlines, and one to Air Greenland. One more example is reported to have been ordered in an executive configuration.
The A330-800 is a direct replacement for the Airbus A330-200, which, in Delta’s premium-heavy configuration, seats 223 passengers. At the other end of the spectrum, Hawaiian’s leisure-focused A330-200s seat 278. With the new winglets and more efficient Rolls-Royce Trent 7000, the A330-800 now has a range of 8,100 NM (15,000 km) at a Maximum Takeoff Weight of 251 tonnes, and this is the issue.
The A330-200 that the A330-800 is based on was developed as a shrink of the original A330-300 (replaced by the A330-900). As such, the A330-200/800 is more expensive to operate per-seat than its larger counterparts. In the past, the A330-200 sold due to its additional range, but as the A330-300 grew more capable, sales for the A330-200 dried up. With the A330-900 now having up to 7,350 NM (13,600 km) of range, almost no airline is willing to sacrifice economics for the extra miles.
The Decline Of Short-Fuselage Variants
Photo: Wirestock Creators | Shutterstock
In airliner design, manufacturers typically create the base design (Airbus A320, Boeing 757-200, Airbus A330-300, Boeing 777-200), then they will either shrink the fuselage (Airbus A319, Airbus A330-200) or stretch the fuselage (Boeing 757-300, Boeing 777-300). Shrinking typically results in a more capable plane with higher per-seat costs, while a stretched variant boasts the best per-seat costs but also has less range.
Manufacturers don’t always develop their aircraft in this manner (both Airbus A350 variants are optimized for their size), but this is typically how commercial aircraft are designed. This approach generally proved successful, as the A330-200 made up 46% of passenger A330ceo sales, while the A319, A320, and A321 were all popular. For first-generation A320 variants, only the A318 was a sales flop, with this variant being a shrink of a shrink.
Today, however, the A330-800 is far from the only reengined shrink that’s been unpopular. The A319neo has only received 57 orders, while slightly over 300 orders have been received for the Boeing 737 MAX 7. The 777-8’s development has been paused, and even sales for the Boeing 787-8 have slowed down dramatically. As the larger version of an airliner becomes more capable, such as during a re-engine program, demand for the shrink disappears.
Why Airbus Doesn’t Care About Selling A330-800s
Photo: EA Photography | Shutterstock
From a manufacturer’s position, a shrink allows you to capture a broader segment of the market by addressing the shortcomings of the original model. However, such jets are priced lower than a larger model, but cost practically the same to produce, thereby generating lower profit margins. Manufacturers prefer to sell larger variants whenever possible, as they generate the highest profits.
When significant demand exists for a smaller aircraft that is more capable, manufacturers will price it competitively. The sale price is a significant component in whether an airliner wins an order, and, as such, selling an A330-200 may have yielded lower profits than an A330-300 in the past, but this was still preferable over losing an order to the Boeing 767.
With the A330-800, however, airlines aren’t lining up to buy it, and Airbus spent little on developing it. The A330-900 captures nearly all of the market, and this variant generates higher profit margins. As such, Airbus is incentivized to price the A330-900 competitively, while the A330-800 has low demand and generates lower profits, so Airbus likely budges little on pricing. This lowers demand for the A330-800 even further, but Airbus would still rather sell more A330-900s.
The Bottom Line
The Airbus A330-800 has been sold to three airlines. This is the only widebody in Air Greenland’s fleet and is used for flights to Copenhagen, directly replacing an Airbus A330-200. For Kuwait Airways and Uganda Airlines, the type serves as a small, efficient, cheap widebody that has incredible capability. Kuwait Airways also operates the A330-900, making it easier for the airline to integrate it into the fleet.
While the A330-800 has so far proven a sales dud, Airbus is not focused on the variant’s individual orderbook. Rather, Airbus aims to make money on the A330neo program as a whole, and selling more A330-900s appears to be a winning strategy for the European planemaker. As such, the A330-800 will likely go down as one of the industry’s rarest birds, similar to other reengined shrinks like the Airbus A319neo.
Boeing
Delta Air Lines
