What split scimitar winglets do

A split scimitar winglet is a vertical fin attached to the wingtip of an aircraft that reduces fuel burn by changing how air flows around the wing. Instead of a single solid winglet, a split scimitar has two separate blades — one pointing up and one pointing down — that work together to cut drag. The design is most common on Boeing aircraft, particularly the 737, where it can lower fuel consumption by 4 to 5 percent on a typical flight.

The winglet solves a real aerodynamic problem. As a plane flies, high-pressure air under the wing wants to escape outward and upward, creating swirling vortices at the wingtip. These vortices waste energy and force the engine to work harder. A split scimitar interrupts this flow by using its two blades to redirect air more efficiently, so less fuel is needed to maintain altitude and speed.

Key Takeaways

  • Split scimitar winglets reduce fuel burn by 4 to 5 percent by changing how air moves around the wingtip, lowering operating costs for airlines.
  • The design uses two separate blades — one up, one down — rather than a single winglet, which makes it more effective at controlling wingtip vortices.
  • Boeing developed split scimitars for the 737 and later added them to other aircraft, and they are now standard on many new commercial planes.
  • Airlines can retrofit split scimitars onto older aircraft, though the cost and downtime mean most choose them on new purchases.

How the two-blade design works

The upper blade of a split scimitar winglet points upward and outward, while the lower blade points downward and outward. This split arrangement is more efficient than a single tall winglet because it uses both the upper and lower surfaces of the wing to manage airflow. The upper blade catches the high-pressure air trying to escape from below the wing, while the lower blade helps direct the wake behind the aircraft in a way that reduces overall drag.

The curved shape — the "scimitar" part of the name — matters as much as the split. The blades curve backward slightly, which helps them blend smoothly with the airflow rather than creating turbulence. This curve, combined with the two-blade split, makes the winglet work at different speeds and altitudes without losing efficiency.

Fuel savings and operating costs

Airlines measure winglet performance in fuel burn reduction, and split scimitars typically deliver 4 to 5 percent savings on long flights. On a Boeing 737 flying a 3,000-mile route, that can mean 200 to 300 gallons of fuel saved per flight. Over a year, with multiple flights per day, the savings add up to tens of thousands of dollars per aircraft.

The cost to install split scimitars on a new aircraft is built into the purchase price, usually adding $500,000 to $1 million to the total. For airlines buying new planes, this cost is often worth it because the fuel savings pay for the winglets within a few years. Retrofitting an existing aircraft costs more in labor and downtime, so most airlines only add them during scheduled maintenance or when buying new planes.

Which aircraft use split scimitar winglets

Boeing introduced split scimitars on the 737 in the early 2000s and has since added them to the 777 and 787. Airbus, Boeing's main competitor, uses a different winglet design called sharklets on the A320 family, which serve the same purpose but have a different shape. Other manufacturers like Bombardier and Embraer have also adopted winglet technology on their regional jets.

Not every aircraft has winglets. Older planes like the 737 Classic and early 737 NG models were delivered without them, though many have been retrofitted. Cargo aircraft and military planes sometimes skip winglets because the trade-offs differ — a cargo plane might prioritize maximum payload over fuel efficiency, or a military aircraft might need different aerodynamic properties.

Winglets versus other fuel-saving technologies

Split scimitars are one tool among several that airlines use to cut fuel burn. Blended winglets — an earlier design that blends smoothly into the wing — reduce drag but not as effectively as split scimitars. Sharklets, used by Airbus, achieve similar fuel savings through a different shape. Folding winglets bend upward at the gate to fit in airport parking spaces, solving a practical problem that split scimitars do not address.

Airlines also reduce fuel burn through engine upgrades, lighter materials, and better flight planning software. A new aircraft with modern engines, lighter composite fuselage, and split scimitars will burn significantly less fuel than an older plane with winglets alone. Winglets are one piece of a larger efficiency puzzle.

Why airlines choose split scimitars over other designs

Split scimitars became popular because they deliver strong fuel savings without requiring major changes to the aircraft structure. A single tall winglet would be more efficient in theory, but it would be heavier and create handling problems at the gate and during taxiing. The split design balances aerodynamic performance with practical constraints — it is light, it fits in standard airport gates, and it works reliably across the speed and altitude range that commercial aircraft encounter.

Boeing's decision to make split scimitars standard on new 737s also drove adoption. When a major manufacturer includes a feature on every new aircraft, airlines get used to it, maintenance crews learn how to service it, and the supply chain develops around it. This network effect makes split scimitars the default choice for new narrow-body aircraft.

Maintenance and durability

Split scimitar winglets are made from aluminum or composite materials and are designed to last the life of the aircraft — typically 25 to 30 years. They require regular inspection for cracks or corrosion, especially where they attach to the wing, but they do not need routine replacement. If a winglet is damaged by a ground vehicle or weather, it can be repaired or replaced without taking the aircraft out of service for long.

The main maintenance concern is the attachment point. Winglets experience significant stress during takeoff, landing, and turbulence, so the bolts and brackets that hold them to the wing are inspected regularly. Airlines follow manufacturer guidelines for inspection intervals, which are usually every few years or after a certain number of flight hours.

Frequently Asked Questions

Do split scimitar winglets make planes quieter?

Winglets reduce noise slightly by changing how air moves around the wingtip, which reduces the intensity of wingtip vortex noise. However, the main source of aircraft noise is engine exhaust, so winglets are not a primary noise-reduction tool. Modern engines are far more effective at cutting noise than winglets are.

Can a plane fly safely without winglets?

Yes. Winglets improve efficiency but are not required for flight. Older aircraft without winglets fly safely every day. Airlines add winglets to new aircraft because the fuel savings justify the cost, not because the plane cannot operate without them.

Why do some winglets fold up?

Folding winglets bend upward at the gate to fit into standard airport parking spaces. Split scimitars are short enough to fit without folding, but some aircraft use taller winglets that would hit the gate structure, so they fold for ground operations and unfold in flight.

How much does a split scimitar winglet cost to replace?

Replacement cost varies by aircraft type and whether labor is included, but typically ranges from $50,000 to $150,000 per winglet. This is why airlines repair damaged winglets when possible rather than replacing them outright.

Do winglets work on all aircraft types?

Winglets work best on aircraft that cruise at high altitudes and fly long distances, where fuel efficiency matters most. Small regional jets and short-haul aircraft see less benefit, so they are less likely to have winglets. Military and cargo aircraft have different priorities and may not use them at all.