Best Practices for Airport Obstruction Management Guidebook (2019)

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72 Key Insights The airport sponsor has primary responsibility for protecting the airport’s approach, departure, and other airspace surfaces, but cannot do it alone. Close coordination and a good working relationship with nonairport stakeholders is vital to protecting airspace surfaces where they extend off airport property. The most effective obstruction management strategy is for the airport sponsor to be pro­ active and work with the local community to establish programs to avoid the development of man­made obstructions and to proactively manage natural vegetation before it becomes an obstruction. When an airport has obstacles that must be removed or mitigated, an obstacle action plan details the approach to resolving the obstacles. An obstacle action plan may be required by the FAA before funding other development, to ensure that the airport is properly addressing its obstacles. Key Definitions 14 CFR Part 77: Safe, Efficient Use and Preservation of the Navigable Airspace (FAR Part 77): Federal regulations that contain the requirements and criteria for the determination of obstructions to air navigation, navigational, and communication facilities and the evalua- tion of their effect on the safe and efficient use of navigable airspace and air navigation facilities and equipment. Section 77.25 establishes imaginary surfaces around airport runways, approach zones, and navigable airspace in the vicinity of the airport. Airport land use zoning: Land use zoning specific to an airport typically provides land use controls and height controls. This land use zoning can take the form of a use zoning or it may be a special zoning district. The local zoning may include maps specific to the zoning or reference the airport layout plan. Depending on the purpose of each zone, the protections may include restrictions for height, noise, and/or land use. Avigation easement: The property right acquired from a landowner for the use of airspace above a specified height. Categorical exclusion (CATEX): A category of actions that do not individually or cumu- latively have a significant effect on the human environment and for which neither an envi- ronmental assessment nor an environmental impact statement is required. (Documentation C H A P T E R 7 Airport Obstruction Mitigation and Management Plan Development

Airport Obstruction Mitigation and Management Plan Development 73 in the form of a categorical exclusion checklist still must be prepared by the airport or its sponsor.) Easement: The right a property owner grants to another for a specific use of their property. Environmental assessment (EA): An assessment of the environmental effects of a proposed action for which federal financial assistance is being requested or for which federal authoriza- tion is required. The environmental assessment serves as the basis for the FAA’s environmental impact statement or finding of no significant impact. Environmental impact statement (EIS): A document prepared under the requirements of the National Environmental Policy Act of 1969, Section 102(2)(c) representing a federal agency’s evaluation of the effect of a proposed action on the environment. (The FAA will serve as the sponsor of an environmental impact statement.) Exhibit A property map: A drawing of the dedicated airport property, including detailed information on how the property was acquired, the funding source for the land, and whether the land was conveyed as federal surplus land or government property. Federal grant assurance: A provision of a federal grant agreement to which the recipient of federal airport development assistance has agreed to comply. High set-aside areas: A voluntary but coordinated initiative among the airport, local jurisdic- tions, and real estate development stakeholders, which directs taller real estate development into area(s) that have fewer adverse effects on air navigation. Such development may be codified into local ordinances and exceed imaginary surfaces and standards in exchange for the prevention of impacts on surfaces and standards more critical for local airports. Instrument approach procedure (IAP): A series of predetermined maneuvers for the orderly transition of an aircraft under instrument flight conditions, from the beginning of the initial approach to a landing or a point from which a landing may be visually made. National Environmental Policy Act (NEPA): A U.S. environmental law that established a U.S. national policy promoting the enhancement of the environment. The National Environmental Policy Act requires each federal agency to disclose to the public a clear, accurate description of the potential environmental impacts that a proposed federal action and reasonable alternatives to that action would cause. Obstacle action plan (OAP): A document identifying the airport sponsor’s proposed approach to mitigate obstacles penetrating the approach and/or departure surfaces in an expe- dited manner, to the maximum extent possible, and to address the sponsor’s action plan to maintain clear surfaces. Surface Analysis and Visualization (SAV) tool: An FAA tool that analyzes object penetration to the visual area surface of an instrument approach using a risk-based approach. Transfer of development rights (TDR): A voluntary, incentive-based program included in a zoning ordinance that allows landowners to sell development rights from their lands to a developer or other interested party who then can use these rights to increase the density of development at another designated location. Visual area surface: The obstacle identification surface that covers the segment of a final approach between the approach procedure decision altitude and landing threshold point, during which a pilot visually descends to the runway touchdown point. Zoning ordinances: Ordinances that divide a community into zones or districts, according to the present and potential use of properties, for the purpose of controlling and directing the use and development of those properties.

74 Best Practices for Airport Obstruction Management Guidebook 7.1 Airport Sponsor’s Responsibility Previous chapters in this report have discussed the foundation for airport obstruction management regulations and how obstacles are identified. This chapter focuses on managing and mitigating obstruction impacts. This chapter addresses common and unique obstruction circumstances, the existing methods of obstruction management or mitigation, mitigation planning, and special considerations or items of concern during obstruction management. Specifically, the chapter focuses on the following: • Obstruction prevention methods, including avigation easements and local airport protection zoning • Development of an OAP to address existing obstructions • Environmental considerations and potential concerns related to obstruction mitigation • Special considerations in obstruction mitigation related to air carrier airports Ultimately, obstruction mitigation and management is part of an airport sponsor’s responsi- bility to protect the airport and its airspace from encroachment. Airport sponsors that accept federal grant funding are required to accept 39 grant assur- ances, or commitments, as part of the grant. Among these assurances are four that establish the federally obligated airport sponsor’s responsibility to maintain clear airport approach and departure surfaces: • Grant Assurance 19: Operations and Maintenance. The airport shall be operated in a safe and serviceable condition and in accordance with appropriate minimum standards required by applicable agencies. The airport sponsor will not cause or permit any activity that would interfere with its use for airport purposes. • Grant Assurance 20: Hazard Removal. The airport sponsor will assure that such terminal airspace as is required to protect instrument and visual operations to the airport (including established minimum flight altitudes) will be adequately cleared and protected by removing, lowering, relocating, marking, lighting, or otherwise mitigating airport hazards and by pre- venting the establishment or creation of future airport hazards. • Grant Assurance 21: Compatible Land Use. The airport sponsor will take appropriate action, to the extent reasonable, including the adoption of zoning laws, to restrict the use of land adjacent to or in the immediate vicinity of the airport to activities and purposes compatible with normal airport operations, including landing and takeoff of aircraft. • Grant Assurance 29: Airport Layout Plan. The airport sponsor will keep up-to-date at all times an ALP of the airport (which shows obstacles on the plan and profile sheets). Also, in certain states, airports that accept state airport improvement funds are subject to state airport grant assurances. As discussed in Section 2.4, some states have enacted regulations requiring local jurisdictions, which often also serve as airport sponsors, to adopt, administer, and enforce regulations protecting the airports from obstruction impacts. Airport sponsors should be familiar with the stipulations of state grant acceptance and other regulations because they pertain to airport airspace protection and obstruction management. Beyond grant assurances, airport sponsors that carry out certain capital improvement proj- ects on the airport are required to gather and submit to the FAA airport data collected in accordance with the requirements of FAA AC 150/5300-18B, as discussed in Section 4.1. The data submitted to Airports GIS often includes data on objects around the airport. If these objects have an impact on an airport’s airspace, the FAA may require the airport sponsor to have a plan to mitigate or manage identified obstructions or be subject to action from the FAA to maintain airspace safety.

Airport Obstruction Mitigation and Management Plan Development 75 Thus, it is an airport sponsor’s responsibility to protect the airport’s airspace from impacts by objects of all types. To do this, an airport sponsor needs to engage in obstruction manage- ment and—when an obstruction cannot be prevented—obstruction mitigation. The obstruction management techniques available for off-airport areas and areas on airport or under airport con- trol (e.g., avigation easements) differ. This chapter covers the various responsibilities, methods, options, and techniques available to airport sponsors for the purpose of airport obstruction management and mitigation. 7.2 Obstruction Prevention Methods There are two types of potential obstructions an airport sponsor must address: man-made and natural (vegetation). For man-made objects, the most effective obstruction manage- ment technique is to have strategies in place to avoid the development of obstructions. For natural objects, the ability to proactively manage vegetation is important. For off-airport man-made objects, obstruction avoidance requires working with surrounding govern- mental entities and landowners to protect the airport’s approach and departure surfaces where they extend off airport property. Off-airport obstruction avoidance techniques may include the following: • Avigation easements • Airport zoning ordinances • High set-aside areas • TDR • Purchase of development rights For on-airport man-made objects, an airport sponsor should have full control over all airport- owned land to avoid the development of obstacles that would affect instrument procedures. This control needs to be included in all leases of airport property. A sample building and land lease, presented in ACRP WebResource 6: Resources for Managing Small Airports, contains a clause in Article 29: Right of Flight that protects the airport’s navigable airspace. The airport sponsor should have or obtain control over vegetation to be able to manage its height. This control can be a fee simple ownership, avigation easement, or right-of-entry agree- ment for the maintenance of vegetation. Avigation Easement Through the FAA grant assurances, airport sponsors have an obligation to protect their approach surfaces and maintain compatible use on adjacent land. Because it is often not feasible for a sponsor to own and control all of the land near its airport, avigation easements (less com- monly referred to as aviation easements) are a common first line of protection for an airport. While easements do not provide the same level of control as fee simple ownership, they are less expensive and can allow land to stay in private ownership. Avigation easements should provide more rights to the airport sponsor than simple obstruction clearing. One of the rights typically included is overflight by aircraft and all the impacts that pertain to overflight. An easement is the legal right to use someone else’s land for a specific purpose. As detailed in FAA AC 150/5100-17: Land Acquisition and Relocation Assistance for Airport Improvement Program Assisted Projects, there are different types of easements that provide differing levels of protection for an airport. The “model aviation and hazard easement” shown in the first row of Table 7.1 should be the goal, but if other, more limited easements are all that an airport sponsor can acquire, they will still assist with obstruction avoidance and management.

76 Best Practices for Airport Obstruction Management Guidebook Avigation easements should be bound to the land so that if the land is sold, the easement still exists for the new owner. This means the easement “runs with the land.” This is called easement appurtenant, and it provides a potential benefit over zoning laws, because zoning can change or owners may wish to receive exceptions from zoning. As detailed in FAA Order 5100.37B: Land Acquisition and Relocation Assistance for Airport Projects, when acquiring an avigation easement and using or anticipating to seek reimbursement with FAA grant funds, the aviga- tion easement must protect at least the FAR Part 77 height restrictions and restrict current and future use to preclude incompatible development. When using FAA grant funds, environmen- tal documentation must be prepared, as discussed in Section 7.4. If new obstructions are identified and the airport does not have an easement in place, the amount of time to acquire an easement and update the Exhibit “A” property map prior to being awarded an obstruction removal grant could be about a year. This lead time is important to keep in mind for temporary mitigation and the safety of airport users. The value of, and thus the cost of, an avigation easement is based on the difference in the value of the land before and after the easement. This value is determined through an appraisal of the property. If federal funding is anticipated, the easement acquisition must follow the rules of Uniform Relocation Assistance and Real Property Acquisition for Federal and Federally Assisted Programs (49 CFR Part 24). FAA AC 150/5100-17 and FAA Order 5100.37B detail the process to meet the federal requirements for airport projects. The FAA provides an Airport Land Acquisi- tion: Land Project Checklist on its website. The concept of “highest and best use” is central to appraisals and creating a fair value. Highest and best use is defined as the reasonable, probable, and legal use of vacant land or an improved property, which is physically possible, appropriately supported, financially feasible, and results in the highest value. The current use of any given piece of property may or may not be the highest and best use. A height restriction easement placed on farmland in a rural area is likely to have lesser impact on the property value long-term than a similar easement on a piece of vacant land in a downtown or developed neighborhood. Land acquisition and easements are eligible for the Airport Improvement Program if the purpose is to clear FAA AC 150/5300-13A, FAR Part 77 or TERPS surfaces. For the removal of off-airport obstacles with grant funding from the Airport Improvement Program, the air- port sponsor must have at least an easement in place or be granted an easement as part of Easement Scope Property Rights Acquired Duration Model aviation and hazard easement 1. Right of flight at any altitude above acquired surfaces 2. Right to cause noise, vibrations, fumes, dust, fuel particles 3. Prevent erection or growth of all objects above acquired surfaces 4. Right of entry to remove, mark, or light any structures or growth above acquired surfaces 5. Others as necessary Until airport is abandoned Limited avigation easement 1. Right of flight at any altitude above acquired surfaces 2. Prevent erection or growth of all objects above acquired surfaces 3. Right of entry to remove, mark, or light any structures or growth above acquired surfaces Until airport is abandoned Clearance easement 1. Prevent erection or growth of all objects above acquired surfaces 2. Right of entry to remove, mark, or light any structures or growth above acquired surfaces Until airport is abandoned Source: FAA AC 150/5100-17, Figure 2-4: Avigation Easements Table 7.1. Types of avigation easement.

Airport Obstruction Mitigation and Management Plan Development 77 the grant-funded clearing transaction. When addressing vegetation impacts, it is typically preferred to remove the object rather than conduct trimming, because Airport Improvement Program grant funds may not be used to address the same obstacle more than once. For example, if a tree was trimmed 10 years prior to using Airport Improvement Program funds and needs to be trimmed again, the second trimming must be locally funded. Also, if an area has been cleared of trees, it is important that the sponsor maintain the area to avoid the growth of new trees. If an airport sponsor is using only local funds, the sponsor may be able to negotiate a right of entry and removal of the obstacle without acquiring an easement. However, a right of entry typically does not provide long-term obstruction management for the airport sponsor. Easements should be written specifically for the area to be covered. An easement to protect the approach over a runway protection zone will differ from a noise easement a mile from the runway. The FAA Central Region offers a template for an avigation easement. An avigation easement template is also included in ACRP WebResource 7. Airport Protection Zoning Ordinance The acquisition of avigation easements is most common in close proximity to the airport. However, the approach and departure surfaces for an airport served by an instrument approach may extend horizontally up to 10,000 feet (approximately 2 miles) from the runway end. For airports served by a precision instrument approach, the approach surface extends 50,000 feet horizontally (approximately 10 miles). State regulations for tall structures, local airport protec- tion zoning, or both are important tools to protect the areas farther from the airport. While zoning typically provides less control over property than an easement, it can generally be applied to a larger area. As identified in Chapter 20 of FAA Order 5190.6B: Airport Compliance Manual, “zoning is an effective method of meeting the federal obligation to ensure compatible land use and to protect airport approaches.” State Level After the airport sponsor, local jurisdictions are the next level of protection for airport and airspace from encroachment by obstructions. Local communities may be aided in this effort by state laws and regulations. While FAR Part 77 establishes the notification and evaluation processes that underlie airport obstruction management, the federal regulations do not contain or provide any enforcement mechanisms or remedies. Therefore, the enforcement mechanism must be established at the state or local level. To add enforcement capability to FAR Part 77 regulations, some states have enacted regula- tions that codify the obstruction notification requirements and obstruction evaluation criteria of FAR Part 77 or similar criteria at the state regulatory level. These laws and rules commonly mirror FAR Part 77 and focus on regulation or management of height standards but may also add a state requirement, such as a state-issued permit. Local jurisdictions may further strengthen these state regulations by requiring that a copy of a state-issued permit, a local tall structure per- mit, or other evidence of an appropriate FAR Part 77 evaluation be submitted prior to issuing a building permit. In certain cases, state regulations and requirements for a state review may be in place, even when a community has not adopted airport or airspace protection regulations. Although such state regulations add a measure of airspace protection, airport protection zoning carries more enforcement and implementation weight with the existence of pertinent local regulations. A local jurisdiction require- ment for a tall structure proponent to provide proof of meeting the FAR Part 77 notification requirements can protect an airport, even in an area where local airport protec- tion zoning may not be available.

78 Best Practices for Airport Obstruction Management Guidebook For example, in Florida, Chapter 333 of the Florida Statutes includes a provision that requires local governments to adopt, administer, and enforce local airport protection zoning regula- tions, including regulations aimed at obstruction management. However, if the local gov- ernment fails to adopt regulations consistent with the state statute, the Florida Department of Transportation retains tall structure permitting authority for areas within 10 miles of a public-use airport. Airport protection zoning regulations typically do not apply to conditions and structures in place prior to the adoption of the regulations. Such a process, known as “grandfather- ing,” may require that an airport sponsor apply other obstruction management or mitigation measures to such a development to protect the safety and efficiency of the airport’s airspace. Those measures may include adjustment of airport procedures or a fee simple purchase of the subject property. In addition to requirements that all local governments adopt airport protection zoning or hybrid requirements that rely on state or local government protection, certain states require airport sponsors to protect the airport’s airspace from tall structure encroachment if the airport accepts state grant funds for infrastructure development. It is recommended that the airport’s obstruction management program be coordinated with the state aeronautics entity from its inception. This helps ensure that the full range of options and protection levels for obstruction management is considered and correlates with any state requirements. Local Level In states that have laws or rules mandating or enabling local governments to adopt and enforce airport protection zoning regulations, the communities surrounding an airport may have zon- ing that assists the airports in obstruction management or mitigation. If the state regulations provide for such protections, but have not been enabled by the local jurisdictions, the airport sponsor should collaborate with the communities to establish airport-specific zoning aimed at protecting the airport from obstructions and incompatible land use. If a state requires commu- nities to adopt airport protection zoning, failure to do so may result in fines or other penalties. A sample airport protection zoning ordinance is available as a part of ACRP WebResource 7, a companion product to this guidebook. Commonly, local zoning ordinances are based on FAR Part 77 criteria. While such an approach may work in general, through collaborative engagement, the airport’s management and staff should aim to focus zoning protections on surfaces and criteria that are critical to their airport, as discussed in Chapter 3, to ensure that all those criteria are protected. Even when airport zoning regulations are in place, a strong working relationship with local gov- ernment planning and zoning staff is essential to the timely and appropriate implementation of those protections. Establishing relationships with local government planning and zoning staff is an impor- tant component of obstruction management implementation. If the local planning and zoning staff are aware of and understand the airport protection criteria, they are able to inform development proponents about the airport-related review requirements. Also, local planning and zoning staff can assist the airport by alerting airport staff to any proposed or potential development, thereby allowing the airport to evaluate and consider the proposal’s potential impacts. Following the implementation of airport protection zoning, it is equally important for airports to periodically review and, when needed, propose amendments to zoning regulations. This is because FAA regulations and, more frequently, IFPs are subject to change. The establishment and enforcement of local zoning is most effective when the airport has a strong working relationship with local city or county planning staff.

Airport Obstruction Mitigation and Management Plan Development 79 When considering local airspace protection, there are two primary types of local airport land use controls: (1) airport overlay zoning and (2) airport district land use planning or zoning. Airport Overlay Zoning Airport overlay zoning is also referred to as “airspace overlay zoning” or “airport hazard over- lay zoning.” Airport overlay zoning is one of the most common types of airport protection zon- ing. In essence, an overlay is placed over the land use zones that may already be in place, adding overlaying requirements to the zoning criteria. Overlay zoning for an airport is typically used to add height restrictions to an area, but it can be used to restrict types of uses, as well as densities or intensities of use. For example, if airport overlay zoning were to be added to an area zoned as heavy industrial, then that area might be obligated to comply with the additional requirements of the overlay zoning, such as a limitation on new structure heights, requirements for marking or lighting, and a requirement to undergo the OE/AAA process, if applicable. The core purpose of an airport overlay zone is to • Identify potential obstructions before they occur • Restrict the heights of objects in and around airports so that they do not interfere with aircraft operations • Provide a link to the federal and/or state airspace evaluation processes of tall structures • Provide for the compatibility of land use under the airport approaches • Protect the financial feasibility and economic development potential of the airport Overlay zones are often modeled after the FAR Part 77 imaginary surfaces, notably the approach (to protect landing aircraft) and horizontal surfaces (for airport traffic pattern pro- tection), but frequently include some land use compatibility restrictions to help the airport meet its grant assurance for land use compatibility. The overlay zone can extend over multiple types of zoning districts, adding airport protection requirements to each of those areas. Overlays provide an easy way to implement airport protection measures in developed and established areas within the jurisdiction. When an airport is surrounded by multiple jurisdictions, the staff should coordinate with all potentially affected local entities to establish similar airport protection zoning provisions. This can be accomplished by developing similar ordinances for each of the affected local jurisdic- tions or establishing an interlocal agreement between the local jurisdiction, acting as the airport sponsor, and the affected jurisdictions. Generally, the most suitable time to add airport overlay zoning to local land development regulations is when the local jurisdiction is updating a regular land use plan or zoning regulation. However, such overlay regulations can be added to local government zoning provisions at any time. When airport overlay zoning is implemented, the more restrictive criteria of the base or overlay zone will prevail. When establishing airport overlay zoning, the airport should tie the zoning requirements to the most demanding existing or planned instrument procedures for each runway. This protects future airport development and reduces the need to continually update airport overlay zoning as developments occur. Airport overlay zoning may be adopted with reference to the airport’s approved ALP. When changes to the ALP result in a new, approved ALP, the airport overlay should be amended to coor- dinate with the new ALP. Involving local government planning staff as stakeholders in the airport planning process can facilitate the coordination of ALP changes with airport zoning updates. Airport Zoning or Land Use District Plan An airport zoning or land use district is an area within a single local jurisdiction designated for types of uses related to airport operations. With an airport zoning or land use district, the It is essential for an airport sponsor to be aware of the local zoning protect- ing the airport and when the zoning may need to be updated to protect airport improvements.

80 Best Practices for Airport Obstruction Management Guidebook airport and any affiliated uses constitute the base zoning or land use, as opposed to being part of an overlay on another type of use. An airport zoning or land use district can be established as an initial type of use when the local government creates land development regulations or a land use plan, when the specific property undergoes a change in local government control (e.g., follow- ing municipal annexation), or as the result of a change or rezoning to a comprehensive land use plan. With an airport zoning or land use district, the permitted types of land uses and density and intensity of use are well defined. The density and intensity of use also define the maximum permitted height within a zone. While airport zoning or land use districts typically do not con- stitute an obstruction management tool, they should form part of a more comprehensive airport obstruction management strategy. Incorporating the airport zoning overlay or airport land use or zoning district into local gov- ernment GIS applications makes the information readily available for local government staff and the public. Landowners and real estate developers gain the ability to proactively evaluate the development potential of a land parcel and likely restrictions or airport zoning requirements with a few clicks of a mouse. When establishing an airport zoning district or an airport zoning overlay, local communi- ties need to be careful to avoid establishing zoning requirements that are so restrictive that they result in a potential inverse condemnation. Inverse condemnation is when a government agency’s taking of a property so greatly damages the use of a parcel of real property that the loss in use becomes equivalent to the condemnation of the entire property. In the case of inverse con- demnation, the property owners may have a legal claim to payment for the loss of the property use in whole or in part. Additional Obstruction Management Tools for Developed Areas While avigation easements and airport zoning can promote and support airport obstruc- tion management programs, there are additional obstruction management options that airports located in highly developed areas or areas highly in demand for development may find especially useful. These options include the following: • High set-aside area development • TDR • Purchase of development rights All of these options require the airport sponsor to work closely with local governmental enti- ties because all three work in conjunction with local zoning. High Set-Aside Area Development Process Description In circumstances such as a highly developed or highly desirable real estate market, obstruction management necessitates a collaborative approach with the development community. Protect- ing the airspace, especially for air carriers’ OEI, has become a challenge at some commercial service airports that are located close to areas with a high demand for tall structures. In those cases, prohibiting tall structure development in certain areas may not be feasible, and the air- port and funding agencies may not have sufficient resources to obtain avigation easements over properties seeking to develop at the best, or highest, potential for use. Use of high set-aside area development is an option for communities attempting to balance development demand with the needs of an airport, which is an important economic development asset for the community. High set-aside areas aim to focus tall structure development in specific areas around the airport to limit the impact of tall structures on airport operations. This option should be undertaken

Airport Obstruction Mitigation and Management Plan Development 81 in coordination with the real estate development community and local decision-makers. To identify areas available for high set-aside, the airport sponsor first identifies the highest priority areas to be protected in order to provide the approach and departure surfaces for the necessary instrument approach or departure procedures. In identifying these areas, the airport sponsor by default also identifies lower priority areas, where tall structures may have a lesser impact on air- port operations and thus protection is not as critical. These areas are typically identified through the development of a composite map for the airport, discussed in Chapter 6. High set-aside area development should aim to divert tall structure impacts to standard departures, OEI surfaces, final and missed approach segments, and elements of airspace critical to maintaining set minimum vectoring altitudes to areas more suitable for such development. Clearly identifying the goal of the high set-aside area implementation is important in deter- mining which imaginary surfaces and criteria can be impacted or modified without affecting airport operations and which cannot. The high set-aside development process should involve all potentially affected aviation and nonaviation stakeholders to reach mutually acceptable results. Standard Departures Any area identified as a high-rise district is likely to already require departure climb gradients that are not standard for one or multiple runways. Airport users should agree on an acceptable maximum nonstandard climb gradient. The criteria will be different from airport to airport, because it depends on the location of the high-rise area in relation to the extended runway centerlines, prevailing weather patterns, and runway layouts that dictate primary arrival and departure usage. OEI Departures OEI surfaces will likely be the controlling criteria for a runway that is aligned with the pro- posed high set-aside district. Airport sponsors should collaborate with air carriers to establish the necessary corridors for OEI departures. If existing structures impact existing corridors, further impact should be prevented, and a separate turning corridor may need to be developed and protected to preserve long-haul routes that require shallower OEI slopes on departure. Approaches Even if the high-rise district is between the extended centerlines of the airport’s parallel run- ways, many of the approach surface clearance criteria may restrict the heights allowable in that zone or be impacted. This is especially true of the nonvertically guided procedures that create Considerations for Development of Set-Aside Areas for High Rise Development A high set-aside area can be best implemented with the development and use of a composite airspace map that is tailored to the specific development scenario. When developing an airspace composite map of a downtown district or other areas of high-rise structures, the goal of high set-aside area implementation should be clearly identified. • Do the structures in the area already act as controlling obstacles for approach and departure procedures and, therefore, is the intent of the high set-aside development to prevent any further impact (e.g., San Jose, California); or • Is the goal of the area development to maximize the building heights in excess of those that exist, without causing further adverse impacts on the airport (e.g., Miami, Florida)?

82 Best Practices for Airport Obstruction Management Guidebook low, flat surfaces relatively far away from the airport, as described in Section 3.7. Although it is possible to modify these procedures, this only applies in special circumstances for which the FAA may redesign the nonvertically guided procedures to incorporate or adjust step-down fixes or minimum descent altitudes to allow higher building heights in given areas. The FAA is prohibited from incorporating modifications to their TERPS standards as a way of mitigating a substantial adverse effect through the OE/AAA process. However, if the airport requests such a modification as part of a comprehensive high set-aside zoning initiative con- ducted jointly with the various stakeholders in the process, the FAA has been known to develop solutions that benefit the high set-aside area while protecting the airspace. This approach was successful in San Jose, California, and Miami, Florida. Missed Approaches Every IAP has an associated missed approach procedure. When considering the develop- ment of a high set-aside area, the airport should evaluate the impacts on the missed approach procedures serving the approaches on the opposite end of the airport. It is critical to consider all missed approach procedures to prevent an increase to the landing minimums for the affected approach. Minimum Vectoring Altitude The minimum vectoring altitude is the altitude at which controllers know they can freely vec- tor aircraft across an area. This altitude is predicated on 1,000 feet of clearance above the highest obstacle. If the goal is to increase building heights or expand the area’s lateral limits, consider- ation must be given to the minimum vectoring altitude over the area. Steps Following the evaluation and establishment of stakeholder priorities, a composite map of all critical surfaces can be developed, and potential impacts can be coordinated with the FAA Flight Procedures Team and Airports district office staff. Height limitations should be incorporated in local zoning regulations to ensure that the agreed-on maximum development scenarios are adhered to by all process participants. Using the information gathered during high set-aside area development, local zoning should be established or modified to protect the most important approach and departure surfaces while allow- ing penetrations to other surfaces within specific limits. Throughout this process, it is important for the airport to educate the interested and potentially affected stakeholders to help obtain buy-in. Likely interested stakeholders may include the following: • Local officials • The development community • The FAA • Airlines and other airport users • Airport representatives Once the high set-aside areas are established, the associated mapping should be shared with the FAA to be used as a part of the OE/AAA review process. TDR While high-density set-aside areas are a regulatory feature of airport protection zoning, the TDR is an incentive program that can be included in zoning to encourage development that is not compatible with airport operations to occur farther from the airport. This option is useful when the prohibition or limitation of property development near an airport via zoning may lead to development rights issues.

Airport Obstruction Mitigation and Management Plan Development 83 The TDR is a zoning technique used to redirect development. A TDR program has a sending area, in which it is desirable to limit development, and a receiving area, in which development density can be increased through the TDR. This option has been most frequently used to protect farmland and other natural or cultural resources, but a TDR can be used to protect airports from incompatible development, especially tall, high-density development. State regulations that enable a TDR must be in place for a TDR to be used. The TDR allows landowners to be compensated for choosing not to develop their land or to limit development. Under these zoning laws, a landowner is able to separate the development rights of their land from the land itself and transfer these rights to another landowner or developer at another loca- tion. After the development rights to a piece of land are sold to another landowner or developer, the land itself is permanently protected through a deed restriction or restrictive covenant. Devel- opment rights can be purchased by other private entities or by a public entity and later sold to a private entity. To be successful, TDR programs must be tailored to market forces. To have a successful TDR program, in addition to having the enabling regulations in place, the following market forces need to be present: • A buyer who wants what a developer can build using the TDR • A developer who wants to buy the TDR and transfer them to the receiving area • A landowner who is willing to sell the TDR and permanently restrict their land Use of a TDR allows local government to control land use and compensate landowners for restrictions on their properties. Also, following the TDR and development of the property, the protection measures become more permanent, unlike zoning regulations, which can be changed. To establish a TDR program, an airport must work closely with the local government to identify areas unsuitable for specific types of development around the airport. Concurrently, the local governmental needs to identify areas within the jurisdiction in which density could be increased beyond the current zoning by using a TDR. An increased density in these receiv- ing areas needs to be desirable not only to the developer but to the ultimate purchaser of the development. Using a TDR provides a mechanism to encourage development that could affect navigable airspace or hinder airport operations to occur at a more suitable location. Purchase of Development Rights As with the TDR, the purchase of development rights also allows the ownership and devel- opment (use) rights of a property to be separated from the property. However, in the case of a purchase of development rights, the airport sponsor is typically the entity that purchases the development rights of a property in order to control the use of the land, its density and intensity of use, and the allowable height for development of the land. This development control mecha- nism gives the airport flexibility in adjusting the agreement to purchase the rights to fit the spe- cific property. Development rights are generally purchased to decrease the density and intensity or height of the development on the property. Therefore, purchased rights affect the property’s value by limiting its utility to uses that remain permitted under the purchase agreement. Because the property owner retains fee simple ownership of the property, the property can be resold later with all the associated development restrictions. Similar to the TDR option, the pur- chase of development rights has been most commonly used for the preservation of agricultural or environmentally sensitive properties. Nonetheless, the mechanism can be used to address obstruction management matters at airports as well. The flexibility of purchasing development rights and its real property market pricing make it an attractive option for airports that have the fiscal resources to implement it. Unlike the purchase of an easement, the purchase of develop- ment rights is not eligible for federal grant funding.

84 Best Practices for Airport Obstruction Management Guidebook 7.3 OAP Obstruction Data Submission Considerations Even with proactive planning and zoning, as the FAA receives new obstruction data from airport surveys and other submittals, critical obstructions may be identified, such as vegetation that has grown into an airspace surface. When an obstruction is identified, the FAA will require its verification, if not already surveyed, and may require that an OAP be developed by the airport to indicate when and how the identified obstructions will be addressed. Depending on the extent to which an obstruction penetrates an airspace surface, the FAA may also take immediate steps to limit/modify instrument procedures until the identified obstruction is addressed. Before any survey data are submitted through Airports GIS, airport management should identify any obstructions and focus on addressing them. Obstructions are classified based on their impacts to the airport’s imaginary or design surfaces. Obstructions with the most impact should receive obstruction management or removal priority to avoid imminent impacts on airport operations, such as changes to or the suspension of instrument proce- dures. Ideally, any impacts to airport surfaces should be addressed prior to the submittal of data to the FAA, with the post-action condition of the obstruction surveyed and the action clearly noted on the submittal (e.g., tree removal or trimming in the visual area surface). The remainder of the impacts must be identified and prioritized through the OAP. The submis- sion of all such data should be timely and appropriately coordinated through the requisite FAA Airports district office staff. Need for an OAP If the airport sponsor identifies obstacles, an OAP should be prepared. An OAP may also need to be developed to address obstacles that the FAA identifies in its review of surveys and other data. An OAP is most commonly prepared as a reactive tool to resolve obstacles identified around an airport, but it can be used as a proactive tool to address objects before they become obstacles. An example of this approach would be using the OAP to assist an airport in managing vegetation. An OAP template (spreadsheet) is included in ACRP WebResource 7. The FAA Airports district office is responsible for ensuring that airport sponsors properly incorporate the identification and planned mitigation of obstacles penetrating the approach and departure surfaces into master plans, ALP updates, obstruction studies, the FAA 5010 form, the Airports GIS SAV tool, and other relevant documents. The complexity and extent of the OAP will vary based on the obstacles at an airport. It is important that the plan detail any phases needed to accomplish mitigation of obstacles. If the clearance of obstacles is not immediately feasible, the airport sponsor should document the obstacles’ effects and expect the item to be tracked as an open action. Depending on the impact of the obstacle, until it is resolved, a restric- tion may be imposed on the affected IAP(s). Content of the OAP While OAPs vary in complexity, the following elements are typically required: • Identification of obstacles • Resolution plan for obstacle management or mitigation, including prioritization Identification of Obstacles While the FAA’s focus has been on the 20:1 visual surface, an airport sponsor is required to include all airport approach and departure surfaces when identifying obstacles. The

Airport Obstruction Mitigation and Management Plan Development 85 surfaces required to be maintained are those identified by FAA AC 150/5300-13A and FAA Order 8260.3D. If the FAA has identified 20:1 surface obstacles in any approach surface, the airport sponsor is responsible for checking all approach surfaces for 20:1 penetrations, along with the other approach and departure surfaces. When identifying obstacles, it is important to identify the amount of penetration because this drives the potential impact to IAPs. Resolution of Obstacles The potential resolution for obstacles varies based on whether an obstacle is on airport (i.e., within the airport’s control) or off airport (i.e., outside the airport’s control). For obstacles to an existing approach, the timing and the type of proposed resolution depend on the amount of penetration. For existing IAPs, the following are potential resolutions: • Light obstacle: Allows nighttime operations, but visibility is no lower than 5,000 RVR or 1 statue mile. • Lower obstacle: Eliminates night and visibility restrictions but requires a full survey from a licensed surveyor to update the obstacle database. • Remove obstacle: Eliminates night and visibility restrictions. Obstacles off airport property may be difficult to remove or lower. • VGSI: This ground device may be used to mitigate obstructions, provided that – The VGSI is not restricted (no baffling) – The obstacle does not penetrate the VGSI OCS – The VGSI angle is equal to or less than the procedure’s glidepath or vertical descent angle – The VGSI TCH is not more than 15 feet higher than the procedure’s TCH – The VDP is not published, and visibility is not lower than 5,000 RVR or 1 statute mile – The VGSI has been commissioned by the airport’s flight check. When an airport has control over an obstacle, the preferred action is to lower or remove the obstacle to restore the IAP. When it is not feasible to remove the obstacle, lighting the obstacle may allow for the return of nighttime instrument operations but potentially with higher mini- mums. While the airport sponsor is addressing the obstacles, the FAA may restrict the IAP visibility, minimums, or nighttime operations. The FAA’s interim policy for 20:1 notification and mitigation was issued in November 2013 and cancelled in January 2016, and a new policy has not been agreed on. The interim policy included provisions for a mitigation time frame. TERPS criteria do not allow for a mitigation timeline; however, because the Flight Procedures Team and Airports district office staff have been directed to use the SAV tool for notification and mitigation, the FAA is allowing 30 days for an airport to validate the obstructions. After the 30-day validation period, the airport’s response or lack of response is sent to the Flight Standards District Office for a determination on the number of days allowed for an airport to become compliant before the procedures are restricted. 7.4 Environmental Considerations of Obstruction Management Even after an airport sponsor has the appropriate control over property to remove obstruc- tions, if the airport is pursuing federal funding for property or easement acquisition and/or obstruction removal, the appropriate level of environmental documentation must be prepared. Part of this document preparation involves outreach to state and federal resource agencies and Native American tribes. This outreach will help the airport sponsor identify any potential

86 Best Practices for Airport Obstruction Management Guidebook environmental impacts that must be addressed or mitigated. The environmental documentation requirements for FAA actions are defined in the following: • FAA Order 1050.1: Environmental Impacts: Policies and Procedures, which translates the NEPA requirements to the FAA. • FAA Order 5050.4B: National Environmental Policy Act (NEPA) Implementing Instructions for Airport Actions, which is specific to the FAA Airports LOB that oversees Airport Improve- ment Program grants for airports. • Environmental Desk Reference for Airport Actions, which summarizes the special- purpose laws and associated environmental impact categories in order to assist with NEPA implementation. In addition to complying with NEPA, airports may also need to comply with any state envi- ronmental regulations, especially in California, where these regulations may be more restrictive. ACRP Legal Research Digest 22: The Role of the Airport Sponsor in Airport Planning and Environ­ mental Reviews of Proposed Development Projects Under the National Environmental Policy Act (NEPA) and State Mini­NEPA Laws provides a summary of relevant federal and state environ- mental review statues and the responsibilities of various stakeholders. The FAA groups environmental considerations into multiple categories, as identified in FAA Order 5050.4B. Not all categories will apply to all airports or all projects, but each must be reviewed to determine whether or not it is applicable. If applicable, additional analysis is needed to determine whether there would be a potential impact. The FAA has three levels of environ- mental review: • CATEX • EA • EIS An obstruction management project without new airport development is most likely to require the preparation of a CATEX or EA. CATEX A CATEX is the shortest form of an environmental review. Airport projects (referred to as “actions”) that are usually eligible for a CATEX are in Tables 6-1 and 6-2 of FAA Order 5050.4B. These actions, individually or cumulatively, do not normally have a significant effect on the environment. However, some of these actions must be evaluated to determine whether there are any extraordinary circumstances, such as the presence of protected animal species, which would require a more detailed environmental review. As part of this evaluation, for a project disturb- ing new areas, the sponsor should solicit comments from appropriate environmental agencies, including U.S. Fish and Wildlife Service and state wildlife agencies (threatened and endangered species), U.S. Army Corps of Engineers (wetlands), U.S. Department of Agriculture (farm land), and state historical and archaeological resources (cultural resources). Letters soliciting com- ments should include a description of the project, a map, and an exhibit of the project. As part of FAA SOP 5.1: CATEX Determinations, the FAA developed a CATEX form to document a project’s eligibility for a CATEX. An airport sponsor may use a consultant to prepare a CATEX, or it may be internally prepared. Any impact in an environmental category can change a project’s environmental documenta- tion process from a CATEX to an EA, but the most common (extraordinary circumstances) are biological (endangered or threatened species); the National Historic Preservation Act; U.S. Department of Transportation 4(f) or 6(f) areas; wetlands; and coastal resources, where appli- cable. When preparing a CATEX, it is necessary to demonstrate that there are no environmental

Airport Obstruction Mitigation and Management Plan Development 87 impacts. When a project is disturbing new areas, field studies may be necessary as part of a CATEX to demonstrate no impacts. If there are impacts but they can be mitigated, it will be necessary to prepare an EA. EA The EA is intended to be a concise document that takes a hard look at the expected environ- mental effects of a proposed action. Actions normally requiring an EA related to obstruction management are the following: • Categorically excluded actions involving extraordinary circumstances or with mitigatable impacts • Acquiring land for any project typically requiring an EA • New runway construction, major runway strengthening, or runway extension projects • Projects involving prime and unique farmland, navigable waters, or wetlands • Other circumstances that have a controversy because the proposed action involves a special- purpose environmental law Typically, an airport sponsor will use a consultant to prepare an EA. The consultant selection for an EA preparation must be per FAA requirements for the costs to be grant-eligible. The FAA generally is the lead agency for airport project EAs. While not common, there can be a cooper- ating agency that will work with the FAA on the EA. Cooperating agencies are more common when preparing an EIS, which is discussed below. For projects that are not included on the CATEX list but are not anticipated to have an adverse environmental impact, an EA short form may be completed and is usually available from the FAA region. This form can also serve as a screening tool for a project with potential environ- mental impacts. The FAA’s Eastern Region is one of the regions that offers an EA short form. EIS An EIS is typically prepared when an EA identifies a significant impact, or a significant impact is identified before starting an EA. For instance, an EIS is required for a new, commercial service airport in a metropolitan statistical area or a new runway in a metropolitan statistical area. The airport sponsor funds the study for an EIS, which is eligible for Airport Improvement Program grant funding, and the FAA selects the consultant. An EIS is typically a longer, more detailed document. The process is also more involved and starts with a detailed scoping process that includes stakeholder, agency, and public involvement. If a small airport must prepare an EIS, the airport sponsor works closely with the FAA Airports district office to properly scope and implement the process. Potential Environmental Categories Some of the more common obstruction management activities that result in potential envi- ronmental impacts include, but are not limited to the following: • Potential endangered or threatened species habitat impacts related to vegetation removal • Potential wetland impacts related to clearing vegetation in wetlands • Historical impacts for vegetation removal in areas with the potential for historical artifacts • Vegetation clearing in historical neighborhoods or by historical structures • Water quality management if vegetation removal is near a water body • Perceived noise increases when vegetated buffers are removed

88 Best Practices for Airport Obstruction Management Guidebook Even if a sponsor is using local money to address obstruction removal, the special-purpose environmental laws and state laws still must be considered. Nothing exempts the airport spon- sor enacting elements of the airport obstruction management program from meeting the federal or state environmental requirements. Potential Vegetation Mitigation Considerations and Measures Addressing vegetation impacts should include a number of considerations: • Ownership of specific vegetation has to be confirmed prior to any action. A property owner may mistakenly presume they own a tree on a property boundary when it may actually belong to a neighbor. • Access to the vegetation has to be ensured. Adjacent property owners may be unwilling to permit the use of their property for access by personnel and equipment to trim or remove a vegetative obstruction. • Soil erosion due to vegetation removal has to be considered on-site for the property owner and off-site for the adjacent property owners. • Prior to vegetation removal, the airport should address any potential viewshed issues (what is visible from a location) with the property owners or adjacent property owners. Vegetation Mitigation at Bowman Field (LOU) Bowman Field—5 miles from the heart of Louisville, Kentucky—is a crucial reliever for Louisville International Airport and is a busy airport in its own right, with significant GA operations. The property is encapsulated by two golf courses and dense residential development, all of which contain significant tree vegeta- tion. In addition, Bowman Field has the most based aircraft than any other airport in Indiana or Kentucky, making it a vital link in the NAS. Because of the trees on neighboring properties, the airport lost two nighttime instrument approaches in 2011 and all nighttime approaches in the summer of 2013. To remedy the situation and maintain airport operational capabilities, the Bowman Field Airport Area Safety Program began, which involved a consultant to determine current and future obstructions, communicate with neighbors and elected officials, acquire easements, trim or remove obstructions and mitigate for any removals. Current and future tree obstructions were identified, and ease- ments were obtained for the relevant properties. A large amount of trees was removed. To entice landowners and assist in the easement acquisition and removal process, the airport offered a two-for-one replacement for any removed trees, as well as landscaping restoration. The consultant team included a local landscape architecture firm. This collaboration produced a replacement tree guide—an informative book from which landowners were able choose new, compatible trees. The pages are filled with different native trees and variants, grouped by how tall they can grow, thus providing a handy reference for replacement trees based on the height restriction easement. This book, along with compensated tree removal and replacement, was popular with the landowners and provided a win-win solution for the airport and its neighbors.

Airport Obstruction Mitigation and Management Plan Development 89 When dealing with potential habitat impacts, an airport sponsor may be able to choose the season for the work so that mitigation is accomplished when the endangered or threatened spe- cies in question are not present. Also, before removing trees, a sponsor should identify whether there are less invasive techniques, such as cutting a tree and leaving the stump (cut at ground level) rather than grubbing. Using less invasive techniques can minimize ground disturbance, which is especially important when working near waterways and archaeological sites. When con- ducting tree removal in residential areas, removing the tree and replacing it with a shorter species is a common mitigation measure. Also, when replacing the vegetation, the party carrying out the mitigation should ensure that the replacement is not only the proper species for the replant but also that solid protocols are in place to promote effective survival rates. 7.5 Air Carrier Considerations For airports with air carrier or frequent charter operations, developing effective rela- tionships with airport tenants and users can provide a better exchange of information, and this may help the airport protect its users’ need to meet OEI departure requirements. As discussed in Section 3.5, air carriers operating under FAR Part 121 or Part 135 or ICAO Annex 6 regulations are required to evaluate departure paths for obstacle clearance in the event of an engine-out. As discussed in Chapter 3, the standard ratio for an OEI OIS slope is 62.5:1, and FAA AC 120-91 and ICAO Annex 6 OEI describe standard splays that encompass large areas. The FAA allows air carriers to perform an analysis to reduce the area to be included in the OEI. There are two key analysis methods: (1) the area analysis method and (2) the flight track analysis method. As a result of airport and air carrier specific analysis, the OEI surface splays can vary substan- tially based on the operator, type of the aircraft, operational needs specific to the air carrier, and the method used for OEI analysis. Therefore, mitigating existing or potential OEI obstructions as a part of the comprehensive obstruction management program requires substantial coordi- nation among the airport, its users and tenants, and the surrounding communities that benefit from the service provided by the airport’s users. While the overall coordination process between the airport and nonairport stakeholders is similar to that of mitigating non-air-carrier surface impacts, the diversity of requirements specific to air carriers and the focus on specific air capacity concerns are what make this process unique. Identifying the affected airport or airspace users is the first step in reactive or proactive OEI impact mitigation. Even facilities that do not have scheduled air carrier service may be frequently served by companies operating as on-demand FAR Part 135 operators. Identifying and engag- ing those users makes the evaluation process more inclusive and reduces the likelihood that a particular set of operations will be adversely impacted by a proposal. The next step is identifying the operational requirements or limitations of the identified air- port users. The intent of the inquiry is dependent on the nature of the OEI impact mitigation— whether it is conducted to proactively improve or maintain the present operational conditions or is the result of a proposal that may negatively affect operations. For proactive obstruction management, the airport should engage with each of the identified airport users and estab- lish, based on air service market conditions, existing and potential future needs and the type of analysis to be conducted and what OEI slope ratio would clear the current controlling obstacle. Furthermore, if a full obstruction survey has been conducted and additional obstacle data are available, the airport may reach out to air carrier users and evaluate hypothetical conditions following the removal or lowering of the controlling obstacle. Ultimately, the goal would be to obtain the maximum or least restrictive OEI surface for all potentially affected airport users based on their maximum operational capacity, as supported by an air service study.

90 Best Practices for Airport Obstruction Management Guidebook When reactively responding to a tall structure proposal, the airport should conduct a similar outreach, with the goal of determining whether the proposal would affect any of the airport users by limiting aircraft passenger, cargo, and fuel loads. A basic economic impact analysis can indicate the real-world direct and indirect economic consequences of a proposal on air service and economic activity for the region. Based on the analysis and findings, the airport sponsor may choose to codify the OEI surfaces as a part of any airport protection regulations to protect the airport’s economic viability. 7.6 Working with State Aviation Agencies to Manage Obstructions As discussed in previous sections, state aviation or aeronautics agencies have many connec- tions to airport obstruction management tasks, whether through establishing or requiring air- port protection zoning or land regulations or by providing airport obstruction data collection services. As such, in addition to state-related obligations, state agencies frequently have a broad range of resources that can help airports with obstruction mitigation tasks. All airports have to be aware of potential obligations that are based on state regulations related to airport obstruction management. As discussed in Chapter 2, state laws or regulations may contain requirements obligating airport sponsors to address obstructions—on and off airport—through management, mitigation, permitting, or any combination thereof. Addition- ally, airports should be familiar with any potential airport criteria (e.g., state airport licensing) that may be affected by unmitigated obstructions and lead to concerns and conflict with the state aviation or aeronautics agency. Obstruction mitigation may be a part of grant assurances in states that offer airport improvement funds. Moreover, other (nonaviation) state entities, such as planning, environmental, or historical preservation, may require coordination during the obstruction management process. However, despite a range of potential obligations that may encumber an airport and mandate obstruction management options, state aviation agencies offer a valuable reference and resource with many potential benefits. Airports that lack technical or financial resources to implement obstruction data collec- tion may benefit from state initiatives to provide data collection and mitigation services. As an example, states that conduct free Airport Master Record data updates for airports may collect and provide basic obstruction data to airports. For example, the South Carolina Aeronautics Commission provides such a service through the use of unmanned aerial system technology supported by ground surveys using total stations for data gathering. Several states that offer airport improvement funds make those funds available for airports to conduct obstruction data collection or obstruction removal tasks. The funds may be available for vegetation harvesting, fee simple property acquisition, or even the purchase of avigation easements. Despite relatively limited state airport improvement funding, states generally have a broader authority to authorize some projects that may not qualify for federal funds. Airports should be aware that receiving funds to trim or mitigate vegetation might preclude the airport from qualifying for such funds in the future if the vegetation grows to the point of a repeat impact on air navigation. In addition to fiscal or technical resources, state agencies may be available to use permit- ting or regulatory requirements to argue for the enforcement of airport protection zoning provisions with reluctant members of the real estate development community or the general public. State aeronautics agencies tend to maintain ongoing working relationships with other state agencies and the FAA and are thus able to serve as liaison for the airport, other state agencies, and the FAA.

Airport Obstruction Mitigation and Management Plan Development 91 Airports that are preparing to implement a comprehensive airport obstruction manage- ment program should consider the following steps when working with their state aeronautics agency: • Identify applicable state requirements for obstruction management • Identify state responsibilities and airport obligations or responsibilities to the state aeronau- tics agency • Identify state obstruction management funding sources and funding obligations and limitations • Continue to coordinate with and involve state aviation or aeronautics staff in obstruction program functions