Airports and Air Transport: Policies for Growth
141
from South Africa to the Arab Republic of Egypt—has the most ATC installations. Ghana, Nigeria, Tanzania, Uganda, and Zimbabwe have some. But the rest of Africa, including Ethiopia—one of the region’s important hubs—lacks coverage. Malawi once had some installations, but the equipment became too expensive to maintain and fell into disrepair; it is no longer salvageable. Even the existing ATC installations do not necessarily use radar separation, which is a technique for issuing directions and headings to aircrafts based on radar images. East Africa is typical. In Kenya, only Nairobi uses full-time radar vectoring,4 while Mombasa switches to radar procedures only if weather conditions demand it. Tanzania has a good radar installation in Dar es Salaam, with a secondary radar range in excess of 300 kilometers (km), but lacks radar-certified controllers and therefore cannot use radar vectoring. The Ugandan military provided the country with radar services, using aged technology, until a new civilian system was installed in 2008. This unsatisfactory pattern is common throughout Africa. The safety risks that it entails will only grow as traffic increases. The lack of radar coverage in the region is not an insurmountable challenge. Modern surveillance technology is moving away from radar installations toward the more advanced (and cheaper) automatic dependent surveillance-broadcast (ADS-B). In this system, the aircraft determines its position using a global navigation satellite system and transmits it to a ground station, which then relays it to the ATC center. Positions obtained using modern global positioning system (GPS) technology can be accurate within 30 meters, avoiding the challenges of using radar technology to locate aircraft accurately at long distances and to detect changes in their speed. ADS-B helps separate aircraft, which is not a problem in lightly trafficked areas, and provides important navigation information to pilots. Some ADS-B systems also allow nearby aircraft to broadcast their positions to one another, provided they have the proper equipment. ADS-B is being considered in a planned redesign of ATC in the Southern African Development Community (SADC) region. The air transport sector could clearly benefit from this new surveillance technology, which is only about a quarter of the cost of radar systems and has lower maintenance costs. In future, most aircraft will probably have their own GPS, and airports will learn to take advantage of the technology as it becomes more widespread. Most airports in the region with an estimated capacity of 1 million passengers or more have an instrumented landing system (ILS).5 They