6% Fuel Savings: How Riblets and Sharkskin Are Making Aircraft More Efficient

The aerodynamics engineers at Lufthansa Technik stared at their test results in 2022, hardly believing what they were seeing. The microscopic grooves they had applied to a Boeing 777 freighter’s fuselage—each one thinner than a human hair—were delivering fuel savings of 1.1% on every flight. Across an airline’s fleet, that translates to millions of dollars saved annually and thousands of tons of carbon dioxide kept out of the atmosphere.

Welcome to the world of riblets, where nature’s 400-million-year-old engineering solution is finally taking flight on commercial aircraft.

What Sharks Taught Us About Drag

The connection between shark skin and aircraft efficiency emerged from an unlikely place: competitive swimwear. In the early 2000s, researchers studying why sharks move so efficiently through water discovered something remarkable. Their skin isn’t smooth—it’s covered in tiny tooth-like structures called dermal denticles, arranged in precise V-shaped patterns.

These microscopic ridges do something counterintuitive. Rather than creating more friction, they actually reduce drag by disrupting the chaotic vortices that form in the boundary layer—the thin envelope of air or water that flows directly over a moving surface. Without riblets, this boundary layer becomes turbulent, creating small spinning vortices that increase drag. The riblets channel these vortices, reducing their energy and keeping flow more organized.

NASA first tested riblet technology on aircraft in the 1970s and 1980s, applying adhesive films with microscopic grooves to test aircraft. The results were promising—drag reductions of 6-8% on treated surfaces. But the technology faced a practical problem: the films degraded quickly, required precise application, and couldn’t withstand the harsh environment of commercial aviation.

The Engineering Challenge

Creating riblets that work on aircraft requires extraordinary precision. The grooves must be exactly 50-100 micrometers wide—roughly the width of a human hair—and spaced at precise intervals. Too wide, and they don’t affect the boundary layer. Too narrow, and they fill with dirt and lose effectiveness.

The orientation matters too. Riblets must align within 15 degrees of the airflow direction, which varies across different parts of the aircraft. The nose experiences different flow patterns than the tail, and the wings present their own challenges.

Early riblet films also struggled with durability. Commercial aircraft fly through rain, ice, sand, and ultraviolet radiation. They’re washed with harsh chemicals and subjected to temperature swings from -60°F at cruise altitude to over 100°F on hot tarmac. Films that worked in wind tunnels fell apart in real-world operations.

Lufthansa’s Breakthrough

Lufthansa Technik’s AeroShark technology, developed in partnership with BASF, represents the first riblet system durable enough for commercial aviation. The secret lies in the paint itself—rather than applying a film, the riblets are embossed directly into a specialized coating using a patented process.

The company began testing on a Boeing 777F freighter in 2022, covering approximately 3,700 square feet of fuselage surface—about 10% of the aircraft’s total area. Flight data confirmed a 1.1% reduction in fuel consumption, translating to roughly 400 tons of jet fuel saved annually per aircraft.

In late 2024, Swiss International Air Lines became the first passenger carrier to operate AeroShark-equipped aircraft, applying the technology to their Boeing 777-300ER fleet. The airline projects annual savings of 4,800 tons of CO2 across their long-haul fleet.

The Numbers That Matter

A 1% fuel saving might sound modest, but the economics are staggering at airline scale:

• Single aircraft: A Boeing 777 burns approximately 7,000 gallons of jet fuel on a transatlantic flight. At $3 per gallon, a 1% reduction saves $210 per flight—or roughly $75,000 annually for an aircraft flying daily long-haul routes.
• Fleet-wide impact: A major airline operating 50 widebody aircraft could save $3.75 million annually in fuel costs from riblet technology alone.
• Environmental benefit: Each gallon of jet fuel burned produces approximately 21 pounds of CO2. A 1% reduction across the global airline fleet would eliminate roughly 7 million tons of carbon emissions annually.

The 6% drag reduction figure comes from treating larger portions of the aircraft surface. Current applications cover only 10-15% of the airframe, focusing on areas with the most turbulent flow. Full coverage—including wings, tail surfaces, and engine nacelles—could theoretically achieve the 6% target, though practical and cost considerations limit current applications.

Beyond Paint: Other Drag Reduction Technologies

Riblets represent just one approach to drag reduction. Airlines and manufacturers are pursuing several complementary technologies:

Laminar flow control: Boeing’s 787 features specially designed engine nacelles that maintain laminar (smooth) airflow over a larger portion of their surface. Natural laminar flow can reduce drag by 5-10% on treated surfaces, though it requires extremely smooth manufacturing tolerances.

Hybrid laminar flow: Active systems that use suction to remove the boundary layer entirely, maintaining laminar flow even at higher speeds. Airbus tested this technology on an A340 demonstrator, achieving 10% drag reduction on the vertical tail.

Winglets and sharklets: These wing-tip devices reduce induced drag by disrupting wingtip vortices. Modern split-tip winglets like those on the Boeing 737 MAX deliver 1.5-2% fuel savings.

Aerodynamic sealing: Closing gaps around control surfaces, landing gear doors, and access panels can reduce parasitic drag by 1-2%.

Implementation Challenges

Despite promising results, widespread riblet adoption faces several hurdles:

Application cost: Applying AeroShark to a single widebody aircraft costs approximately $200,000-300,000, with the coating lasting 5-7 years before requiring reapplication. Airlines must weigh this upfront cost against projected fuel savings.

Maintenance considerations: While riblet coatings are designed to withstand normal operations, they can be damaged by ground equipment contact, hail, or improper cleaning. Repairs require specialized application equipment.

Regulatory approval: Any modification to aircraft surfaces requires certification from aviation authorities. Lufthansa Technik spent several years obtaining supplemental type certificates for AeroShark applications.

Surface coverage limitations: Current technology works best on relatively flat surfaces with predictable airflow. Complex geometries around engines, wing roots, and control surfaces present application challenges.

The Future of Drag Reduction

Research continues on next-generation riblet technologies. MIT engineers are developing “morphing” riblets that can change their geometry in flight to optimize for different speed regimes. Other researchers are exploring riblet patterns inspired by different marine species, including dolphins and fast-swimming fish.

3D printing technology may eventually allow riblets to be incorporated directly into aircraft structural components during manufacturing, eliminating the need for post-production application entirely.

As aviation faces increasing pressure to reduce its carbon footprint, technologies like riblets offer a practical path to meaningful emissions reductions using current aircraft designs. While electric and hydrogen-powered aircraft remain decades away for long-haul routes, riblets can start saving fuel—and reducing emissions—today.

The sharks figured this out 400 million years ago. It just took us a while to catch up.