SANSA oversees the ‘standard reference’ compass against which all aircraft compasses are calibrated, and also sees to the functioning of warning systems in respect of solar storms. Based at Hermanus in the Western Cape, the Agency has been selected by the International Civil Aviation Organization (ICAO) as one of two regional centres to provide space weather services, including solar storm forecasts and warnings, to the global aviation sector. This selection is based on the premise that space weather could be volatile and cause the disruption of more than a few activities, one of which is flights.
“With aviation, we consider four key risk areas – communication, navigation, avionics and radiation exposure,” said SANSA MD, Dr Lee-Anne McKinnell. “High-frequency radio communication, as well as ground and air-based navigation systems, can be affected or knocked out entirely by space weather storms. Delicate electronics can also be damaged, and radiation exposure poses a hazard for crew and passengers, particularly on long haul flights.” Space weather can also have a major knock-on effect on airlines and airports.
SANSA also focuses on compass accuracy, which is directly integral to aviation. Despite the rise of modern navigation systems such as GPS and radio aids, compasses are still an essential component of aircraft navigation equipment. Compasses require constant monitoring to determine the degree of variation at any given location.
According to SANSA, a proper compass swing procedure is necessary to determine how to measure and compensate for the magnetic field of the actual aircraft, which will cause a deviation to the compass reading once located in the cockpit, due to the proximity of steel or iron components, and by the effects of current flowing in nearby electrical circuits. The compass must, therefore, be swung at predetermined intervals, usually at the annual Mandatory Periodic Inspection, or when the magnetic properties of an aircraft are deemed to have changed, as usually results from a direct lightning strike.
A calibrated reference compass is required to have a proper compass swing, and it must be done in a magnetically clean environment free of steel structures, underground cables, or equipment that produces magnetic fields, to ensure freedom from interference. It must also be done by qualified personnel. SANSA’s Space Science facility in Hermanus is the only SACAA accredited South African facility that offers this type of service with the necessary expertise and facilities to perform training in the compass swing procedure on-site.
SANSA has been presenting training courses on the execution of compass swings to the South African Air Force for more than 20 years and recently hosted a five-day Compass Swing Training Course and a three-day Compass Swing Refresher Course. The course is presented by SANSA engineers and physicists who have many years of relevant magnetic navigation ground support experience.
The relevance of SANSA to South Africa’s aviation industry cannot be over-emphasised, and furthermore, it is an illustration of the importance of space science and technology to any country’s private and public sectors. A functional space sector would help a country in the provision of accurate weather information as well as warnings pertaining to natural disasters. Technical issues at airports (or worse still, aeroplane crashes) would reduce to the bare minimum if more space-related facilities are provided and expanded.
This article is adapted from SA Space Agency’s Key Role in Aviation, which was originally published by SANSA.