Grid networks have often been a characteristic of domestic air transport. A prime example used to be the US where, before deregulation, many airlines operated grid networks, especially on the eastern seaboard. One of these was the former Eastern Airlines (Figure 4.2). A current example is India, where the domestic airline’s network is very much in the pattern of
a grid, based as it is on the ‘diamond rectangle’ of Bombay/Delhi/Calcutta/ Madras. The main advantage of grid networks is that they make it easier to achieve high rates of utilization, of both aircraft and crews. Flights can be scheduled to operate on a number of different routes without backtracking, which helps to minimize the time for which aircraft are idle on the ground and which also means that crew stopovers and slippage can be minimized. Traffic flows through stations are higher than they are in line networks, but the sales effort is still rather dispersed, a disadvantage that
becomes that much more serious in deregulated or liberalized air travel markets.