Keep a weather eye out
08 Sep 2016
Ever wondered why your flight path into Queenstown comes in either over the lake on what’s referred to as the “05 runway approach” or over the Kawarau Gorge “23 runway approach”? It’s all about wind…
Aircraft must land into the wind and take off into the wind so airport runways are laid out to capitalise on the prevailing winds and the physics of flight.
Airways NZ’s Chief Air Traffic Controller at Queenstown Tower Clayton Lightfoot, a self-confessed wind geek, explains that Queenstown has unusual wind patterns.
“New Zealand’s general wind flow pattern is from the west or south-west but our mountain ranges and valleys act as a funnel and bring the wind straight up the Frankton Arm and the airport’s runway. We also have some local seasonal winds which we need to factor in when assessing what flight track an aircraft will use.
“In summer, the majority of our take-offs and landings are from the Runway 23 (Kawarau Gorge) end. This is because the land warms faster than the lake and the rising warmer air creates a lake breeze which blows up the Frankton Arm.
“In winter or after-dark, the wind often drops or we get a light Katabatic breeze as the cold air sinks into the basin, meaning that Runway 05 (the lake end) gets more use. However, if we get southerly fronts, which bring snow and gusty winds, the wind get funnelled between The Remarkables and Deer Park Heights and Runway 23 has to be used.
“Overall, take-offs/landings are about a 60/40 split in favour of Runway 05 (the lake end) in the winter, and a 70/30 split in favour of Runway 23 in summer.”
As part of Queenstown Airport’s evening flights project, six new weather stations were installed around the airport zone last year which send real-time information, such as wind speed, temperature and other atmospheric conditions, straight to the pilots in the flight deck.