provides unobstructed navigation. A survey of obstructions should be undertaken to identify
those objects which may affect aircraft operations. Protection of airspace can be accomplished
through purchase, easement, zoning coordination, and application of appropriate military
18.104.22.168. Airspace Availability. Existing and planned instrument approach procedures, control
zones, and special use airspace and traffic patterns influence airfield layouts and runway
locations. Construction projects for new airfields and heliports or construction projects on
existing airfields have potential to affect airspace. These projects require notification to the FAA
to examine feasibility for conformance with and acceptability into the national airspace system.
22.214.171.124. Runway Orientation. Wind direction and velocity is a major consideration for siting
runways. To be functional, efficient, and safe, the runway should be oriented in alignment with
the prevailing winds, to the greatest extent practical, to provide favorable wind coverage. Wind
data, obtained from local sources, for a period of not less than five years, should be used as a
basis for development of the wind rose to be shown on the airfield general site plan. Attachment
5 provides guidance for the research, assessment, and application of wind data.
2.7.5. Runway and Helipad Separation. The lateral separation of a runway from a parallel runway,
parallel taxiway, or helipad/hoverpoint is based on the type of aircraft the runway serves. Runway
and helipad separation criteria are presented in Chapters 3 and 4 of this manual.
2.7.6. Runway Instrumentation. Navigational aids require land areas of specific size, shape, and
grade to function properly and remain clear of safety areas.
126.96.36.199. Navigational Aids (NAVAIDS), Vault, and Buildings. NAVAIDS assist the pilot in
flight and during landing. Technical guidance for flight control between airfields may be
obtained from the U.S. Army Aeronautical Services Agency. The type of air navigational aids
which are installed at an aviation facility are based on the instrumented runway studies, as
previously discussed. A lighting equipment vault is provided for airfields and heliport facilities
with navigational aids, and may be required at remote or stand-alone landing sites. A
(NAVAID) building will be provided for airfields with navigational aids. Each type of
NAVAID equipment is usually housed in a separate facility. Technical advice and guidance for
air navigational aids should be obtained from the support and siting agencies listed in
2.8. Aircraft Ground Movement and Parking Areas. Aircraft ground movement and parking areas
consist of taxiways and aircraft parking aprons.
2.8.1. Taxiways. Taxiways provide for free ground movement to and from the runways, helipads,
maintenance, cargo/passenger, and other areas of the aviation facility. The objective of taxiway
system planning is to create a smooth traffic flow. This system allows unobstructed ground
visibility; a minimum number of changes in the aircraft's taxiing speed; and, ideally, the shortest
distance between the runways or helipads and apron areas.
188.8.131.52. Taxiway System. The taxiway system is comprised of entrance and exit taxiways;
bypass, crossover taxiways; apron taxiways and taxilanes; hangar access taxiways; and partial-
parallel, full-parallel, and dual-parallel taxiways. The design and layout dimensions for various
taxiways are provided in Chapter 5.
184.108.40.206. Taxiway Capacity. At airfields with high levels of activity, the capacity of the taxiway
system can become the limiting operational factor. Runway capacity and access efficiency can