Covering 14 million square kilometres Antarctica is nearly twice the size of Australia and accounts for 90 per cent of the world’s fresh water in the form of ice. This ice covers more than 99 per cent of the continent with an average thickness of 2,000 metres and only the coastal rocky outcrops and rising mountain peaks escape the ice sheet. Its average elevation of 2,300 metres makes it the highest continent on earth, the coldest with a recorded temperature of -89.6C and the windiest, with gravity-assisted katabatic winds hurtling down the slopes at up to 320 km/h. The minimal amount of moisture received by the polar plateau compares to the driest deserts on earth.
Antarctica is a unique place and while its mystery and majesty draws scientists and tourists, it also calls for a range of additional considerations for aircraft venturing into the region. //
The nature of the environment is unlike any other into which the airline operates. There are peaks reaching 16,000 feet, although the highest mountain in the potential area of operations is Mount Minto which towers at 13,600 feet. Consequently, the Lowest Safe Altitude (LSALT) for operations is a significant consideration. Additionally, altimetry in the region is based on the United States transition level of Flight Level 180 and given the extremes of temperature, cold temperature corrections are applied to the QNH.
Furthermore, just as altimetry requires special attention, so does navigation which normally uses magnetic North as its reference. Throughout the flight GPS allows a precise track to be flown, however, the heading reference of the aircraft is switched from magnetic to true as the 747 passes 60 degrees South. Less technical, but equally vital, are a series of topographical ‘strip maps’ which add to the overall situational awareness of the crew.
Communications are primarily through (Controller Pilot Data Link Communications) CPDLC and Australian, New Zealand and United States airspace all come into play. Additionally, contact is made with McMurdo station approaching the scenic viewing area and Traffic Information Broadcasts by Aircraft (TIBA) are made on schedule over Antarctica.
As safety is the prime consideration in all flight operations, the importance of a positive handover-takeover procedure between pilots is reinforced to ensure that one pilot is always maintaining a positive watch over the aircraft. And while this may seem self-evident, such amazing scenery as the pilots will witness requires positive cockpit discipline to avoid any lapse in monitoring the aircraft’s flightpath with reference to the instruments.
