Tower for Tomorrow—Christchurch’s New Control Tower

By Hugh Mitton.

The new control tower at Christchurch International Airport opened in September last year; a distinctive addition to the city’s northwestern skyline and a major $7 million addition to Airways New Zealand’s infrastructure. Hugh Mitton took a look inside to find out what the “state-of-the-art” is, exactly.

Viewed from the outside, the new tower looks cool and modern. If you step inside, you will notice that the interior is also cool and modern. This is thanks to a not-inconsiderable weight of concrete, steel and tinted glass. For example, there is a 460-tonne base slab of concrete lying below the ground, keeping the rest firmly upright. At the upper—business—end of the tower, a full six tonnes of glass is required for the “cab’s” massive windows and 24 tonnes of steel form the support for its roof.

Not only is the new tower aesthetically beautiful with its ornamental spiral and night lighting, but—importantly—it also provides extra room for controllers and technical equipment, eliminates blind spots, which the old tower suffered from, and hosts an array of “new” electronic equipment (new is in quotes because while the equipment is new to Auckland and Wellington towers, it has been used at Christchurch since 2007).

Anyone who has been in a control tower before or seen a movie like Pushing Tin will know that the traditional way of managing air traffic is with the use of plastic slates, with each aircraft and flight details attached on a paper strip. These are then arranged appropriately on a board and/or handed between respective controllers. What you might not know is that air traffic controlling isn’t nearly as stressful as Hollywood makes it out to be—at least not in New Zealand.

Much like email and written letters, the installation of electronic touch-screens in the main centre towers abolished the need for the paper strips. The new system is a product of the Austrian company Frequentis, which specialises in air traffic management, and public safety and transport systems. The tower at Christchurch has four sets of displays: one for ground, one for tower, one for delivery and one for flight data, but each is capable of doing the others’ jobs. This also means that should one somehow fail (note the use of “somehow” to emphasise their reliability and the improbability of such a failure), the operation in question could shift to another set, the work of which could be done in tandem for the hour it would take to deliver and install a replacement.

Just as was done with older paper strips, the flight data is added to electronic “smart” strips; these include the same details, such as flight number, destination, tracking points, persons on board and squawk code. Just like the plastic slates of old, information can be passed between operators using a drag-and-drop system. Some of it is automatic; for instance, aircraft taxiing for takeoff will appear on both the ground and tower displays. There is another saving in stationery with the digital system: pens. Each touch-screen has a touch-pen which can be used to add or erase markings on the electronic strips—things like clearances or drawing attention to a flight detail.

Radar data is displayed on regular LCD monitors. Another separate single monitor displays the emergency notification system. This is an impressive piece of technology to minimise incident response times and thereby maximise recovery and survival possibilities. Should an aircraft go down, an appropriate symbol (a light aircraft, turboprop or jet aircraft) can be dragged and dropped onto a map of the area at the estimated or last known location. This information is then sent to all appropriate response services simultaneously, including the airport’s new Rosenbauer fire trucks, in the form of a display matching that inside the control tower.

All of New Zealand’s air traffic control data is processed in Christchurch through Airways New Zealand’s flight data and radar data processors. At present, flight additions or changes made at the tower must be sent back to the flight data processor manually, but an upgrade scheduled for this year will create an automatic two-way link. The obvious question is: what if something fails? While cutting-edge technology might as well be black magic to some people, that edge isn’t used for cutting corners. On the tower’s lower floors lie two large uninterruptable power supply units (which will keep local operations going without a hitch for up to three hours) and, of course, a generator.

With all of Airway’s operations covered for the event of a power failure, that just leaves the computer-related element—the one that is often perceived as the most difficult to trust. Perhaps this is because for many, a computer means a personal computer—the kind that usually induces significant frustration at least once in a person’s lifetime. Airways’ computers are different. They are designed to perform fewer tasks and perform them well; they’re virtually impossible to overload. As for the national data network, it is independently routed to be failsafe.

So there it is—the transition to a digital future for air traffic control in New Zealand. The previous tower at Christchurch airport sits alone atop the old domestic terminal, which is scheduled for demolition this year, along with the much-admired viewing deck. With air passenger numbers only increasing, flight is a fast-evolving being. It’s nice to see Airways keeping up on the ground too.