Chapter 10. Basic

10-3-1. DESIGN STANDARDS

1. For Federally obligated airports, it is the responsibility of the airport proponent/sponsor/planner to comply ­with FAA airport design standards.
2. For non-Federally obligated airports or National Plan of Integrated Airport Systems (NPIAS) airports, it ­should be encouraged that the airport proponent/sponsor/planner comply with FAA airport design standards.
3. It should be noted when airport design standards are combined with appropriate state and local zoning ­ordinances, the resultant effect should:
   1. Assure the lowest possible operational altitudes for aircraft;
   2. Protect the economic investment in the airport; and
   3. Promote safety in the areas affected by the airport by assuring, through proper development, compatible ­land use.

10-3-2. AIRPORT SPACING GUIDELINES AND TRAFFIC PATTERN AIRSPACE AREAS

1. The following guidelines are to be used as aids when evaluating airport proposals. The guidelines may also ­be used to determine airspace requirements to accommodate a given operation under a given condition, areas ­of potential air traffic conflict for aircraft having certain operational and performance characteristics, and the ­degree of aircraft operational flight compatibility with other airports in a given area. These guidelines are not ­to be construed as authorizations for aircraft operations contrary to any Code of Federal Regulations, nor are the ­dimensions to be construed as air traffic separation standards.
2. Aircraft Approach Categories - The factor used to categorize the following aircraft was taken from part ­97. This factor is based on 1.3 times the stall speed with aircraft in landing configuration at maximum certificate ­landing weight.
   1. Category A - Speed less than 91 knots. This category includes civil single-engine aircraft, light twins, ­and some of the heavier twins.
   2. Category B - Speed 91 knots or greater but less than 121 knots.
   3. Category C - Speed 121 knots or greater but less than 141 knots.
   4. Category D - Speed 141 knots or greater but less than 166 knots.
   5. Category E - Speed 166 knots or greater. This category includes, for the most part, those military, ­experimental, and some civil aircraft having extremely high speeds and critical performance characteristics.
3. IFR Radar Airspace.
   1. Air traffic control airspace requirements for a specific runway or airport are generally dictated by the ­approach category of the aircraft that will use the airport and the direction of the associated instrument ­approaches and departures. Based on these factors, the following rectangular airspace areas were developed as ­general guides for the planning or siting of new airports and the designation of instrument runways when IFR ­radar control procedures are contemplated or programmed for a single airport operation, or under certain ­conditions, multiple airport operations. No provisions are made for holding or for procedure turns within the ­airspace areas.
      1. Airports that are regularly used by Category C aircraft or larger: 10 miles in the departure direction, ­15 miles in the direction from which approaches will be made, and 5 miles either side of the extended runway ­centerline.
      2. Airports which are regularly used by Category B and smaller aircraft: 5 miles in the departure ­direction, 10 miles in the direction from which approaches will be made, and 4 miles either side of the extended ­runway centerline.
      3. In metropolitan areas requiring more than one airport: the primary instrument runways at all airports ­should be aligned in the same general direction to allow maximum spacing between airspace areas.
      4. At airports having parallel approaches: the rectangular airspace areas should be applied to each ­runway. Should the instrument runways at an airport have bi-directional instrument approach capabilities, the ­total length of the larger airspace areas should be increased to 30 miles for Category C and D aircraft, and to 20 ­miles for Category A and B aircraft in the smaller airspace areas.
   2. These airspace dimensions will not, nor are they intended to, contain sufficient airspace to provide for ­completely independent IFR operations. Normally, these areas will provide for reasonable operational efficiency ­if the traffic pattern airspace areas of adjacent airports do not overlap. However, in large metropolitan areas where ­there is an extremely heavy mix of en route and terminal traffic, reasonable operational efficiency may not result ­even though the airspace areas do not overlap. Such situations require a thorough review of the procedural ­potential of the area, as well as alternate site considerations. In conducting studies where complete radar ­environments call for the larger airspace areas, and such areas abut each other but do not overlap, there is ­adequate space for:
      1. Approach and departure on the runway centerline.
      2. Two additional tracks offset from and parallel to the runway centerline. A minimum of four miles ­is provided between adjacent tracks of different areas (see FIG 10-3-1).
   3. Where two smaller areas are adjacent but do not overlap, an additional 1-mile spacing is required on two ­of the longitudinal sides (see FIG 10-3-2).
   4. When the anticipated traffic volume at an existing or proposed airport requires additional airspace for ­greater airspace-use efficiency and operational flexibility, expand the airspace, where available, by providing ­a 5-mile buffer area between the adjacent airports involved. This additional airspace will provide two additional ­tracks offset from and parallel to the runway centerlines within the airspace areas of the adjacent airports and ­one additional track for each airport within the 5-mile buffer area. A minimum of 3 miles is provided between ­each track paralleling the runway centerline and each additional track in the buffer area. A 3-mile no ­transgression area is also provided between the two airports (see FIG 10-3-3).
   5. If additional airspace is required in the smaller areas for greater airspace-use efficiency and flexible ­operation, the procedures for determining the additional airspace are identical to those used for the larger areas, ­except that the smaller airspace should be used in lieu of the larger airspace areas. The 1-mile additional spacing ­should also be applied, as outlined in subparagraph b.3. above, in addition to the 5-mile buffer area, as outlined ­in subparagraph b.4. above (see FIG 10-3-4).
4. IFR Nonradar Airspace - A wide range of procedures is available for airspace requirements associated with ­instrument approach procedures at IFR airports without radar services. Therefore, no attempt has been made to ­describe these requirements in detail. However, should it become necessary to determine the airspace ­requirements at such airports, apply the appropriate primary airspace areas and “aircraft approach categories" ­discussed in subparagraph a. above. Additional information is contained in AC 150/5300-13, Airport Design.
5. VFR Airspace - A primary objective in an airport/airspace study is to determine whether compatible VFR ­traffic patterns may be developed for a new airport or when to alter a runway layout at an existing airport located ­in proximity to other airports. Because flight tracks and climb/descent profiles vary when operating in a VFR ­traffic pattern, the following guidelines are offered for use in these studies:
   1. Traffic pattern airspace (see paragraph 6-3-8) of one airport may touch but should not overlap the ­traffic pattern airspace of another airport;
   2. Traffic pattern airspace should be enlarged as described in paragraph 6-3-11 when more than four ­aircraft of the same category operate in a VFR traffic pattern at the same time.

10-3-3. DESIGNATION OF INSTRUMENT RUNWAYS, CHANGES OF AIRPORT STATUS VFR ­TO IFR AND LOWERING MINIMUMS

Requests for designation of instrument runways, which relate to installation or qualification for precision ­landing aids, and proposals for a change in airport status from VFR to IFR, or lowering instrument approach ­minimums usually take one of the following forms:

1. In cases involving Federally obligated airports, the Airports Division must be responsible for coordinating, ­corresponding directly with the proponents, and formulating the official determination.
2. In cases requesting an instrument procedure not involving a Federally obligated airport, the FPT must ­coordinate directly with the proponent.
3. In cases requesting the installation of a NAVAID not involving a Federally obligated airport, the Technical ­Operations Services area office is responsible for coordinating, corresponding directly with the proponent, and ­formulating the official determination.
4. A proposal submitted under part 157 (FAA Form 7480-1) not involving a request for an instrument ­procedure or an installation of a NAVAID, the appropriate Airports Division must be responsible for ­coordinating, corresponding directly with the proponent, and formulating the official determination, regardless ­of which division receives the proposal.
5. A change to the Airport Layout Plan (ALP). The Flight Procedures Team must be responsible for ­coordinating the requests for instrument procedures not involving a Federally obligated airport. Coordination ­of requests for installation of NAVAIDs must be in accordance with Part 4 of this Order. The Airports Office must ­be responsible for coordinating submittals under part 157 and all other construction on a public-use airport, and ­changes to approved ALPs. Designation of instrument runways on all Federally obligated airports must be the ­responsibility of the Airports Division and will be treated in the same manner as a revision to the ALP. Regardless ­of where the coordination begins, air traffic, Technical Operations Services, Flight Standards, Airports, and ­Flight Procedures Team must have an opportunity to review and comment on the proposal. No division/service ­area office must require dual reporting of such a proposal. The responsible coordinating division/service area ­office must correspond directly with the proponent and formulate the official determination.

10-3-4. AIRSPACE FEASIBILITY STUDY

Before expending funds for acquisition of real property, development of the ALP, or plans and specifications ­for new airports and major airfield improvements, feasibility studies or preliminary airport site analyses are ­encouraged. Normally, preliminary airport site analyses are made on all Federal agreement projects involving ­airport site selections. Analyses of this nature allow the agency to evaluate the proposals and advise the ­proponents as to their feasibility from a safety and airspace use standpoint in addition to other related matters. ­Guidance for conducting these airport studies is contained in AC 150/5070-6A, Airport Master Plans. That AC ­describes the major considerations when selecting a site for a new airport for which Federal aid is anticipated. ­Airport studies of this nature are coordinated in the same manner as Federal agreement proposals, except that ­the proposals are not circularized to the public unless specifically requested by the proponent.

10-3-5. ONSITE EVALUATION

The intent of the FAA is to achieve safe airport operations and to fulfill its responsibilities of assuring that unsafe ­conditions will not exist. Therefore, if there is an indication of unsafe conditions or information to evaluate the ­proposal cannot be obtained from the proponent, an onsite evaluation of the proposal must be considered before ­issuing a determination. Such an evaluation may be necessary if the proposal would be located in a congested ­area or the study indicates the presence of obstructions that may affect the safe and efficient use of the airspace. ­An onsite evaluation may also be necessary if information pertaining to the proposal is insufficient for arriving ­at a determination. Airports, air traffic, Flight Procedures Team, Technical Operations Services, and Flight ­Standards personnel must assist in the evaluation as necessitated by the situation requiring evaluation.

10-3-6. FORMULATION OF FAA DETERMINATION

The FAA determination must be a composite of the airspace review and the comments and findings received from ­other interested FAA offices. Should there be a disagreement in the airspace findings or between other comments ­received, the disagreement must be resolved before formulating the FAA determination.