In South Africa, you can go to KFC (Kentucky Fried Chicken) and buy 21 Zinger winglets for 66 rand which is equivalent to about $6.60 in the US.
Winglets are a very successful innovation of aeronautical dynamics and have been known to increase the fuel efficiency of aircraft by as much as 10%. This isn’t from an accidental discovery of a spicy jet fuel additive from the corporate kitchens of KFC. Aircraft winglets are actually vertical extensions of wingtips that have the effect of reducing drag which improves an aircrafts fuel efficiency and cruising range.
A British aerodynamicist actually conceived of winglets in the late 1800’s but it was essentially a theoretical concept until the 1970’s when the spiraling cost of jet fuel encouraged NASA engineers to evaluate the idea in wind tunnel tests using new computer technology. The computer model predicted fuel savings of between 6 and 9 percent. A Boeing 707 jetliner outfitted with winglets was tested by NASA in 1980 and recorded an increased fuel mileage rate of 6.5%.
The shapes and sizes of winglets, and the angles at which they are mounted with respect to the main wings, differ between the many types and sizes of aircraft produced but they all represent improved efficiency.
The savings are simply amazing! An average winglet equipped 737 will save 100,000 gallons of jet fuel per year. Savings climb to 300,000 gallons per year for the larger 757 and 767 Boeing aircraft.
America’s airlines account for approximately one billion gallons of jet fuel consumption per month. North American air traffic historically makes up more than half of the world’s total traffic. Retrofitting winglets on existing aircraft and manufacturing new aircraft with this technology will help reduce US dependence on foreign oil. Burning less fuel also has immediate environmental benefits in the form of reduced emissions.
Pilots report other benefits beyond fuel savings. Improved time to climb performance and cruise stability are typical comments. The extensions reduce lift induced drag and provide some extra lift. Aircraft also have more range due to the more efficient use of fuel. For example, the Boeing 747-400 has increased range of 3.5% over the aerodynamically identical but wingletless 747-400D.
Passengers have a good view of the inboard side of winglets on commercial airliners. Some airlines currently advertise their website addresses to their passengers which are literally a captive audience. Don’t be surprised to see airlines selling this space. How about KFC advertising their winglets on the winglet?