Winglets – old & new

Saturday, 8 March 2014

‘Winglets,’ those little flick up bits at the end of an aircraft’s wings, are all the go. They first appeared on an assortment of gliders and privates jets, but as regular passengers we probably first saw them on the Boeing 747-400 from 1985. Forget the buzzwords and aeronautical science, basically winglets make the wings work better, providing a number of advantages particularly reduced fuel consumption. The 747-400 range improved 3.5% over the otherwise aerodynamically identical 747-300.

Air New Zealand 767 winglet 542

▲ Air New Zealand Boeing 767 with winglets added.

Winglets can be retrofitted on older aircraft, built before winglets came along, but the airline has to balance the fuel saving against the cost of the change and the extra weight, which on very short flights might outbalance the winglet’s aerodynamic improvements. So recently I flew on updated Boeing 767s from Air New Zealand (with winglets added) and Qantas (fancy new interior, but no winglets). Presumably the Qantas aircraft are doing more short flights (shuttling back and forth the one hour between Melbourne and Sydney) and the economics didn’t add up. Adding winglets to an older aircraft can cost a million dollars .

In the last month United Airlines have started rolling out Boeing 737s with a new take on the winglet story. These aircraft have been converted to a ‘split scimitar’ winglet which features one winglet bending upwards and another smaller winglet bending down.

Hewa Bora 727 542

▲ A couple of years ago in Africa – in the Democratic Republic of Congo – I was reassured to note that my nearly 50-year-old Boeing 727 of Hewa Bora Airlines had winglets added. ‘A good sign that they’ve been spending money on maintenance and care fairly recently,’ I thought. A week later the aircraft ploughed into the jungle approaching Kisangani killing most of the crew and passengers.