A successful test flight this week by a Boeing 737-800 equipped with a shiny new set of split scimitar winglets has given the green light for United's plans to install them widely across its 737 fleet. Designed to improve the plane's aerodynamic efficiency by routing air around it, winglets have already been deployed by a number of airlines, however the new scimitar-inspired model is said to be a "significant" upgrade on its predecessors.

United Airlines anticipates its use will cut two percent from the company's 737 fuel bills, with the overall saving growing to $200 million per year when you include winglet designs already in use on 757 and 767 aircraft. FAA certification and testing are expected to be finalized by the end of this year, with United starting to retrofit the split scimitar attachments to its planes in early 2014.