Business Green: Air New Zealand says a new fuel-saving wing device installed on its passenger jets is expected to save the airline more than seven million litres of aviation fuel annually — 19 per cent more than originally anticipated. Developed by Aviation Partners Boeing, the 3.4m devices — called blended winglets — are installed on the end of airplane wings, where they help to reduce wing tip drag, resulting in lower fuel consumption and carbon emissions. The airline installed winglets …