IT IS POINTED OUT THAT UNDER PRESENT OPERATIONAL CONDITIONS A LARGE NUMBER OF AIRCRAFT VERY OFTEN HAVE TO WAIT IN THE STACK BECAUSE THE CAPACITY OF THE RUNWAY FACILITIES IS TOO LOW TO ACCEPT APPROACHING AIRCRAFT FAST ENOUGH. IN ADDITION, AIRCRAFT HAVE TO WAIT IN LINE FOR TAKEOFF. TIME LOSSES CONNECTED WITH THIS PROCEDURE ARE NOT ACCEPTABLE IN AN ERA OF MASS TRANSPORT. THE RUNWAY SYSTEMS OF THE FUTURE MUST BE DESIGNED IN SUCH A WAY THAT AN 'OPTIMUM' NUMBER OF AIRCRAFT MOVEMENTS IS POSSIBLE. GUIDELINES FOR SUCH RUNWAY SYSTEMS ARE DISCUSSED TOGETHER WITH AN ALL- RUNWAY AIRPORT, A THREE-AND FOUR-RUNWAY SYSTEM WITH CONVENTIONAL TAXIWAYS, AND A NARROW EIGHT-RUNWAY SYSTEM. /IAA/