orientation required by local wind conditions. Typical layouts of single and
dual runway systems, dimensions, lateral clearances, and separation criteria are
shown in Section 4. The principal runway systems are as follows:
Single Runway. A single runway is the least flexible and lowest
capacity system. The capacity of a single runway system will vary from
approximately 40 to 50 operations per hour under IFR conditions and up to 75
operations per hour under VFR conditions.
Parallel Runways. Parallel runways are the most commonly used systems
for increased capacity. In some cases parallel runways may be staggered with
the runway lengths overlapping and with terminal or service facilities located
between the runways. When parallel runways are closely spaced the capacity
under VFR conditions is increased but not under IFR conditions.
Triangular Runways. Triangular runways may be either the open-V or the
intersecting type of runway. The triangular system is adaptable to a wider
variation of wind conditions than the parallel system. When winds are mild both
runways may be used simultaneously. An open-V system will have a greater
capacity than the intersecting system.
Runway Classification. Table 1 classifies Class A and Class B runways
by aircraft type. Class A runways are primarily intended for small light
aircraft and do not have the potential for development to heavy aircraft use or
for which no foreseeable requirement for such use exists. Ordinarily, less than
10 percent of runway operations involve aircraft in the Class B category, and
the runways are less than 8000 feet long. Class B runways are all other