Delta Air Lines is steering away from traditional blended winglets on most of its fleet and is completing a sweeping retrofit to split scimitar winglets while investing in a next-generation blended wing body (BWB) aircraft program, marking a decisive shift in its modernization and sustainability plans as of September 1, 2025. The airline says all aircraft that can be modified will carry split scimitar winglets by the end of 2025, and it has no plans for new blended winglet installations.
At the same time, Delta has joined a development push with JetZero to bring a blended wing body to market, with a demonstrator targeted for a first flight in 2027. The strategy focuses on near-term gains from winglet upgrades and long-term change from a new airframe design that could cut fuel burn by as much as 50% compared with the traditional tube-and-wing structure.
Near-term retrofit program: split scimitar winglets
The immediate work is centered on the Boeing 737-800 and 737-900ER fleets, where Delta is finishing a multi-year effort to shift from blended winglets to split scimitar winglets. These retrofits are scheduled during heavy maintenance or coordinated with broader cabin refreshes, which reduces downtime while improving fuel performance and the onboard experience.
- Delta will fit split scimitar winglets on all modifiable aircraft by end of 2025.
- There are no plans to install new blended winglets.
- Aircraft that cannot be modified will remain in service until retirement; Delta will direct future capital to more efficient models and long-term platforms like the BWB.
The retrofit delivers measurable savings: split scimitar winglets generally add 2–3% fuel savings over blended winglets. Delta reports the 737-800 fleet alone saves nearly 3.3 million gallons of fuel per year from the program.
“Delta Air Lines’ unwavering dedication to building a more sustainable future for air travel,” — Craig McCallum, Senior Director of Sales and Marketing, Aviation Partners Boeing (APB)
APB, the supplier of winglet systems, frames Delta’s program as a vote of confidence in retrofit designs. APB executives have publicly thanked Delta for continued backing of advanced winglet products.
Long-term strategy: blended wing body (BWB) with JetZero
Delta’s partnership with JetZero is the second pillar of the strategy. Under the early-2025 agreement, Delta contributes operational input and airline perspective to help shape a BWB airframe that could reset the efficiency baseline for commercial flight.
Key points:
– BWB demonstrator targeted for first flight in 2027.
– Design could reduce fuel use by up to 50% versus current tube-and-wing models (depending on mission/configuration).
– The BWB program offers a potential commercial entry in the 2030s, subject to development, certification, and infrastructure readiness.
The joined-wing planform reduces drag and improves lift distribution—advantages researchers have pursued for decades. Delta’s timeline lets the airline pursue immediate savings (winglets) while preparing operationally and commercially for a step-change platform.
Why winglets matter (a quick technical primer)
Winglets reduce wingtip vortices—the swirling air at wing tips that adds drag—by shaping airflow. Briefly:
- Blended winglets: smooth transition from wing to winglet, historically delivered up to ~5% fuel savings on some types.
- Split scimitar winglets: build on blended winglets with additional elements for better aerodynamic flow, adding typically 2–3% more savings beyond blended winglets.
On high-utilization aircraft like the 737-800/900ER, small percentage gains quickly translate into large absolute fuel and emissions reductions across thousands of flights.
Implementation approach and operational benefits
Delta schedules upgrades during heavy checks and cabin refreshes to limit disruption. This approach achieves multiple goals:
- Minimize aircraft downtime by combining tasks during planned maintenance.
- Roll out incremental efficiency improvements fleetwide without disrupting daily operations.
- Pair winglet retrofits with cabin upgrades so passengers experience refreshed interiors alongside performance gains.
- Reduce fleet configuration complexity, easing maintenance planning and fuel performance tracking.
For flight crews, a standardized winglet configuration simplifies performance planning and reduces variability in takeoff/climb profiles.
Limits, trade-offs, and practical challenges
Delta acknowledges constraints and trade-offs:
- Not every aircraft can be modified (structural, certification, or economic reasons).
- Split scimitar winglets add weight and require certification and structural checks.
- The BWB program faces additional hurdles: test campaign, regulatory review, pilot training, maintenance adjustments, and airport operations changes (gates, ground handling).
- These are manageable but require time, coordination, and planning.
Regulatory and infrastructure considerations
The Federal Aviation Administration plays a central role in certifying both winglet retrofits and any new BWB aircraft. Airlines must meet airworthiness standards; airports may need to consider gate spacing and ground handling adjustments.
For more on regulatory processes, see the Federal Aviation Administration: https://www.faa.gov 🇺🇸
Environmental and economic impact
Delta ties the retrofit schedule to its broader target of net-zero emissions by 2050. Winglet retrofits provide immediate, measurable emission reductions and operating cost relief while the BWB aims for a much larger long-term step.
- Example benefit: ~3.3 million gallons saved per year on the 737-800 fleet.
- Small percentage improvements (2–3%) become large absolute savings when applied across many flights and aircraft.
Environmental groups generally praise the pace of Delta’s winglet transition and its leadership in the BWB partnership, while noting broader BWB adoption depends on regulatory approvals and airport infrastructure adjustments.
Stakeholder perspectives
- Aviation Partners Boeing (APB) views Delta’s purchases as confirmation of the retrofit’s value.
- Delta’s Chief Sustainability Officer, Amelia DeLuca, calls the JetZero collaboration “bold and important work” toward net-zero by 2050.
- Analysts call the mix of retrofit (near-term, proven gains) and research (ambitious, longer-term) a balanced approach.
Commercial and competitive implications
- If successful, the BWB would be particularly valuable for long-haul and high-density routes where aerodynamic efficiency matters most.
- Delta’s early role gives it influence over design decisions—potentially affecting cabin layouts, payload ranges, and turnaround processes tailored to its network.
- Delta’s move away from blended winglets signals to peers that the older design has been surpassed in cost-benefit terms.
Maintenance, logistics, and workforce impacts
Behind the scenes, maintenance planners manage parts, trained crews, and test procedures during tight windows so aircraft flow remains steady. Coordinating interior refreshes with winglet retrofits creates more consistent passenger experiences and avoids a stark split between “old” and “new” aircraft.
For airports and staff:
– Split scimitar winglets require minimal gate-operation change but call for added care around wingtips.
– The BWB could change boarding flows, emergency procedures, and gate fit assumptions—requiring advance planning and coordination.
Summary timeline and program takeaways
- Retrofit program: fit split scimitar winglets on all modifiable aircraft, finishing where feasible by end of 2025.
- BWB development: JetZero demonstrator targeted for 2027 first flight, with potential commercial entry in the 2030s.
- Near-term focus: maximize fuel and emissions savings today via proven retrofit technology.
- Long-term focus: invest operational expertise into a potential BWB that could reduce fuel burn by up to 50%.
Key takeaway: Blended winglets served their era; split scimitar winglets are the immediate retrofit standard, and the blended wing body represents a possible next chapter—if development, certification, and infrastructure align.
Where to follow updates
For official program details and timelines:
– Delta Air Lines Newsroom: https://news.delta.com
– Delta’s Sustainability Initiatives: https://news.delta.com/sustainability
– Aviation Partners Boeing (winglet technology): https://www.aviationpartnersboeing.com
– JetZero (BWB program): https://jetzero.com
– Federal Aviation Administration (regulatory guidance): https://www.faa.gov
These sources provide the latest facts on retrofits, demonstrator milestones, and certification guidance.
Final note for travelers, employees, and investors
- Travelers: Expect subtle visible changes (smoother winglet shapes, refreshed cabins) and incremental environmental improvements.
- Employees: Expect ongoing hands-on retrofit work, training, and coordinated maintenance scheduling.
- Investors: The changes signal measurable cost savings today and a strategic investment in a potentially transformative airframe for the future.
Delta’s plan is concrete and time-bound: retrofit through 2025, contribute operational expertise to the BWB design, aim for a 2027 demonstrator flight, and build toward possible commercial use in the 2030s. The direction is clear—use proven tools now and pursue a next-generation aircraft that could substantially rewrite the efficiency math of commercial flight.
This Article in a Nutshell
Delta Air Lines is executing a two-track modernization and sustainability strategy: immediate fleet retrofits with split scimitar winglets and a long-term investment in a blended wing body (BWB) program with JetZero. Delta will install split scimitar winglets on all modifiable aircraft by the end of 2025, focusing initially on Boeing 737-800 and 737-900ER fleets during heavy maintenance and cabin refreshes to limit downtime. The winglet upgrades yield roughly 2–3% additional fuel savings over older blended winglets, producing measurable gains — the 737-800 fleet saves about 3.3 million gallons of fuel per year. Concurrently, Delta contributes operational expertise to JetZero’s BWB demonstrator, targeted for first flight in 2027, with potential commercial entry in the 2030s and fuel-burn reductions up to 50% depending on configuration. The combined approach offers immediate emissions and cost benefits while positioning Delta to influence a possible transformational aircraft design, subject to certification, infrastructure, and operational challenges.
