Source: https://alanarmstronglaw.com/hazards-of-excluding-aircraft/
Timestamp: 2020-01-23 07:51:54
Document Index: 660767476

Matched Legal Cases: ['§47101', '§47101', '§47101', '§47104', '§47102', '§47105', '§47111', '§47107', '§47521', 'art 150', 'art 150', '§47501', '§47102', 'art 150', '§150', '§150', '§150', 'art.\n14', '§150', '§150', '§150', '§150', '§150', 'art 150', 'art 150', 'art 150', '§150', '§150', '§150', 'art 150', 'art 150', '§150', '§150', '§150', '§150', '§150', '§150', '§47152', 'art 16', '§16', 'art 16', '§41713', '§16', 'art 16', 'art 36', '§47501', '§47521', '§47502', 'art 150', 'art 150', '§47107', 'art 161', 'art 16', '§47152', '§16', '§16', '§16', 'art 150']

Importance of Airport Noise Studies - Alan Armstrong Law
It is the FAA public policy to maintain public airports as part of a national transportation system. In conflict with this policy, many local governments fail to enact or enforce airport zoning ordinances. As a result, public airports throughout the United States now neighbor growing residential communities. Inevitably, private home owners are filing noise complaints concerning airport use. Local governments have responded by imposing aeronautical noise restrictions and curfews on public airport activities. Many of these restrictions do not, however, initially document residential noise concerns with a noise study. In failing to conduct an initial noise study, local governments may find it impossible to respond to complaints by pilots, aircraft operators and aeronautical users asserting infringement of their right to public airport access in violation of FAA Sponsor Grant Assurances. This article discusses the legal architecture that limits the ability of local governments to impose restrictions on aircraft operations at public airports without first conducting a noise study.
HAZARDS OF EXCLUDING AIRCRAFT OPERATIONS AT A PUBLIC AIRPORT WITHOUT FIRST CONDUCTING A NOISE STUDY
FAA SPONSOR GRANT ASSURANCES AND UNDERLYING STATUTES
A. FAA Policy As Relates to the National Airway System and Airports
“It is the policy of the United States…that the safe operation of the airport and airway system is the highest aviation priority.”[1] It is further the policy of the United States “to give special emphasis to developing reliever airports.”[2] It is further FAA policy that restrictions on airport capacity:
(C) should not discriminate unjustly between categories and classes of aircraft.[3]
The primary way the FAA ensures that airports are available to serve the airway system is by employing project grants. The project grant authority is described as follows: “To maintain an efficient nationwide system of public-use airports that meets the present and future needs of civil aeronautics, the Secretary of Transportation may make project grants under this subchapter from the Airport and Airway Trust Fund.”[4] The term “public airport” is defined as “an airport used or intended to be used for public purposes – that is under the control of a public agency; and … of which the area used or intended to be used for landing, taking off, or surface maneuvering of aircraft is publicly owned.”[5] Public airports that are part of the National Airspace System are funded by DOT/FAA project grant applications that satisfy project requirements and that entail the public airport executing grant agreements (or written assurances), in favor of the FAA.[6] In the event that the sponsor of a public use airport violates the project grant agreements, the Secretary of Transportation may withhold a payment under a grant agreement “for more than 180 days after the payment is due only if the Secretary – (A) notifies the sponsor and provides an opportunity for a hearing; and (B) finds that the sponsor has violated the agreement.”[7]
[1] 49 U.S.C. §47101(a)(1).
[2] 49 U.S.C. §47101(a)(3).
[3] 49 U.S.C. §47101(a)(9).
[4] 49 U.S.C. §47104(a).
[5] 49 U.S.C. §47102(21)(A), (B).
[6] 49 U.S.C. §§47105, 47106, 47108.
[7] 49 U.S.C. §47111(d)(A), (B).
B. FAA SPONSOR GRANT ASSURANCE NO. 22a AND UNDERLYING STATUTES
Among the Sponsor Grant Assurances, the sponsor of a public airport must execute attendant to receiving federal funds to make improvements to the airport is Grant Assurance No. 22a which provides:
It (the airport sponsor) will make the airport available as an airport for public use on reasonable terms and without unjust discrimination to all types, kinds and classes of aeronautical activities, including commercial aeronautical activities offering services to the public at the airport.
49 U.S.C. §47107(a) provides, inter alia:
The Secretary of Transport may approve a project grant application under this subchapter for an airport development project only if the Secretary receives written assurances satisfactory to the Secretary, that — (a) the airport will be available for public use on reasonable conditions without unjust discrimination…
C. Federal Law Preempts State Law in Matters of Aircraft Noise
City of Burbank v. Lockheed Air Terminal, Inc., [8] is a leading case concerning preemption of local noise ordinances by federal law. The City of Burbank enacted an ordinance making it unlawful for pure jet airport to take off from the Hollywood-Burbank Airport between 11:00 p.m. of one day and 7:00 a.m. the next day, and making it unlawful for the operator of that airport to allow any such aircraft to take off from the airport in such periods.[9] An action was brought by the owner/operator of the airport and an interstate air carrier against the City and alleging that the ordinance was invalid. The District Court found the ordinance was unconstitutional on both Supremacy Clause and Commerce Clause grounds.[10] The United States Court of Appeals for the Ninth Circuit affirmed on grounds of the Supremacy Clause both in terms of preemption and in respect to conflict.[11] The United States Supreme Court found Congress had occupied the field by virtue of the United States possessing exclusive sovereignty over the airspace of the United States.[12] The Supreme Court further noted the district court found:
The imposition of curfew ordinances on a nationwide basis would result in a bunching of flights in those hours immediately preceding the curfew. The bunching of flights during these hours would have the twofold effect of increasing an already serious congestion problem and actually increasing, rather than relieving, the noise problem by increasing flights in the period of greatest annoyance to surrounding communities. Such a result is totally inconsistent with the objectives of the federal statutory and regulatory scheme.[13]
Curfews increase congestion, cause loss of efficiency, and aggravate the noise problem.[14] Because Congress enacted the Noise Control Act of 1972, which placed full control of aircraft noise in the jurisdiction of the Federal Aviation Administration and the Environmental Protection Agency, the United States Supreme Court found that the City of Burbank ordinance was preempted by federal law. In doing so, they affirmed the lower court decisions declaring the ordinance unconstitutional.[15]
It being clear that aircraft noise falls within the jurisdiction of the FAA and the EPA, Congress passed 49 U.S.C. §47521 providing, inter alia:
(2) community noise concerns have led to uncoordinated and inconsistent restrictions on aviation that could impeded the national air transportation system;
(5) community concerns can be alleviated through the use of new technology aircraft and the use of revenues, including those available from passenger facility charges for noise management…
[8] City of Burbank v. Lockheed Air Terminal, Inc., 411 U.S. 624, 93 S.Ct. 1854, 36 L.Ed.2d 547 (1973).
[9] 411 U.S. at 625-626.
[12] Id. at 626-627.
[13] Id. at 627-628.
[14] Id. at 628.
D. Noise Studies – A Prerequisite to Finding Incompatibility Between the Airport and Surrounding Land Uses
14 C.F.R. Part 150 “prescribes the procedures, standards, and methodology governing the development, submission, and review of airport noise exposure maps, and airport noise compatibility programs, including the process for evaluating and approving or disapproving those programs…”[16] 14 C.F.R. Part 150 “applies to the airport noise compatibility planning activities of the operators of ‘public use airports,’ including heliports, as that term is used in §47501(2) as amended (49 U.S.C. 47501, et seq.) and as defined in §47102(17) of 49 U.S.C.”[17]
For purposes of 14 C.F.R. Part 150 an airport includes: “(A) any airport which is used or to be used for public purposes under the control of a public agency, the landing area of which is publicly owned; (B) any privately owned reliever airport; and (C) any privately owned airport which is determined by the Secretary to enplane annually 2,500 or more passengers and receive scheduled passenger service of aircraft, which is used or to be used for public purposes.”[18]
14 C.F.R. §150.7 provides the following definition:
Airport noise compatibility program and program means that program and all revisions thereto, reflecting end documents (and revised documents) developed in accordance with Appendix B to this part, including the measures proposed or taken by the airport operator to reduce existing non-compatible land uses and to prevent the introduction of additional non-compatible land uses within the area.
Further, 14 C.F.R. §150.7 provides:
Noise exposure map means scaled, geographic depiction of an airport, its noise contours and surrounding area developed in accordance with section A150.1 of Appendix A of this part, including the accompanying documentation setting forth the required descriptions of forecast aircraft operations at that airport during the fifth calendar year (or later) beginning after submission of the map, together with the ways, if any, those operations will affect the map (including noise contours and forecast land uses).
14 C.F.R. §150.9(a) provides:
The noise at an airport and surrounding areas covered by a noise exposure map must be measured in A-weighted sound pressure level (LA) in units of decibels (dBA) in accordance with the specifications and methods prescribed under Appendix A of this part.
14 C.F.R. §150.9(c) provides:
Uses of computer models to create noise contours must be in accordance with the criteria prescribed under Appendix A of this part.
The identification of compatible as opposed to non-compatible land uses is prescribed in 14 C.F.R. §150.11 which provides:
For the purpose of this part, uses of land which are normally compatible or non-compatible with various noise exposure levels to individuals around airports must be identified in accordance with the criteria under appendix A of this part. Determination of land use must be based on professional planning criteria and procedures utilizing comprehensive or master, land use planning, zoning, and building and site designing, as appropriate. If more than one current or future land use is permissible, determination of compatibility must be based on that use most adversely affected by noise.
14 C.F.R. §150.21(b) provides:
Each map, and related documentation submitted under this section must be developed and prepared in accordance with appendix A of this part, or an FAA approved equivalent, and in consultation with states, and public agencies and planning agencies whose area, or any portion of whose area, of jurisdiction is within the Ldn 65dB contour depicted on the map, FAA regional officials, and other federal officials having responsibility for land uses depicted on the map. This consultation must include regular aeronautical users of the airport. The airport operator shall certify that it has afforded interested persons adequate opportunity to submit their views, data, and comments concerning the correctness and adequacies of the draft noise exposure map and descriptions of forecast airport operations. Each map and revised map must be accompanied by documentation describing the consultation accomplished under this paragraph and the opportunities afforded the public to review and comment during the development of the map. One copy of all written comments received during consultation shall also be filed with the Regional Airports Division Manager.
14 C.F.R. §150.21(c) provides:
The Regional Airports Division Manager acknowledges receipt of noise exposure maps and descriptions and indicates whether they are in compliance with the applicable requirements. The Regional Airports Division Manager publishes in the Federal Register a notice of compliance for each such noise exposure map and description, identifying the airport involved. Such notice includes information as to when and where the map and related documentation are available for public inspection.
An airport operator submits a noise compatibility program under 14 C.F.R. §150.23 to the Regional Airports Division Manager who acknowledges receipt of the program and conducts a preliminary review of the submission.[19] If the Regional Airports Division Manager finds the submission does not conform to the requirements of Part 150, he disapproves and returns the unacceptable portion of the program to the airport operator for reconsideration and development of a program in accordance with Part 150.[20] If the Regional Airports Division Manager finds the program conforms to the requirements of Part 150, he publishes in the Federal Register a notice of the receipt of the program for comment including the following:
(1) the airport covered by the program, and the date of receipt;
(2) the availability of the program for examination in the offices of the regional airports division manager and airport operator;
(3) that comments on the program are invited and, will be considered by the FAA.[21]
14 C.F.R. §150.33(a) provides:
The FAA conducts an evaluation of each noise compatibility program and, based on that evaluation, either approves or disapproves the program. The evaluation includes consideration of proposed measures to determine whether they –
(2) are reasonably consistent with obtaining the goal of reducing existing non-compatible land uses and preventing the introduction of additional non-compatible land uses;
(3) and include the use of new or modified flight procedures to control the operation of aircraft for purposes of noise control, or affect flight procedures in any way.
14 C.F.R. §150.35(a) provides:
The FAA issues a determination approving or disapproving each airport noise compatibility program (and revised program). Portions of a program may be individually approved or disapproved. No conditional approvals will be issued. A determination on a program acceptable under this part is issued within 180 days after the program is received under §150.23 of this part or it may be considered approved, except that this time period may be exceeded for any portion of a program relating to the use of flight procedures for noise control purposes. A determination on portions of the program covered by the exceptions to the 180 day review period for approval will be issued within a reasonable time after receipt of the program. Determination relating to the use of any flight procedure for noise control purposes maybe issued either in connection with the determination on other portions of the program or separately. Except as provided by this paragraph, no approval of any noise compatibility program, or any portion of the program may be implied in the absence of the FAA’s express approval.
14 C.F.R. Part 150, Appendix A relates to noise exposure maps. 14 C.F.R. §A.150.1(a) provides:
This appendix establishes a uniform methodology for the development and preparation of airport noise exposure maps. That methodology includes a single system of measuring noise at airports for which there is a highly reliable relationship between project noise exposure and surveyed reactions of people to noise along with a separate single system for determining the exposure of individuals to noise. It also identifies land uses which, for purposes of this part are considered to be compatible with various exposures of individuals to noise around airports.
The foregoing provisions set forth in 14 C.F.R. Part 150 ensure that incompatibility between aeronautical activities at an airport and surrounding land areas must be bona fide and demonstrated with scientific and empirical evidence.
[16] 14 C.F.R. §150.1.
[17] 14 C.F.R. §150.3.
[18] 14 C.F.R. §150.7.
[19] 14 C.F.R. §150.31(a).
[20] 14 C.F.R. §150.31(b).
[21] 14 C.F.R. §150.31(c)(1), (2), (3).
E. City of Pompano Beach – A Roadmap to Defeating Restrictions on Airports Based on Noise Concerns
Aircraft Owners and Pilots Association (AOPA) members: Bill Bahlke, Reagan L. Dubois, Howard G. Soloff, Lawrence K. Melgrin, David Watkins, Joseph Hawhe, Robert Kwass, Herbert Jacobs, and Levent Erkmen v. City of Pompano Beach, Florida,[22] involved the City of Pompano Beach that enacted a number of ordinances between March 23, 1972, and November 25, 2003. These ordinances restricted access to the airport as related to (a) stop-and-go operations, (b) intersection takeoffs, (c) touch-and-go operations, (d) taxi-back activity, and (e) prolonged running of aircraft engines, as well as (f) inclusion of rotorcraft in these restrictions. Moreover, the City of Pompano Beach enacted these restrictions without providing appropriate supporting justification and demonstrated.[23] The Pompano Beach Air Park became available for development as a public use airport as a consequence of quitclaim deeds executed in 1947 and 1948 in favor the City of Pompano Beach pursuant to the Surplus Property Act of 1944, as amended (49 U.S.C. §47152(2)). Among the covenants contained in the quitclaim deeds from the United States Government to the City of Pompano Beach were requirements very similar to Grant Assurance No. 22(a) that the airport would be made available to all classes and types of aeronautical users without unjust discrimination. There were two issues in City of Pompano Beach, to-wit: (1) Whether the ordinances violated the quitclaim deeds executed under the Surplus Property Act of 1944 requiring the airport be available to the public on reasonable terms and without unjust discrimination; and (2) Whether the City of Pompano Beach by invoking various restrictions and limitations on aeronautical operations was in violation of the exclusive rights provision contained in the quitclaim deeds executed pursuant to the Surplus Property Act of 1944?[24] In passing on these questions, the Airport Director of the FAA, in rendering his decision noted: “The FAA considers it inappropriate to provide federal assistance to improve airports where the benefits of such improvements will not fully be realized due to inherent restrictions on aeronautical activities.”[25]
The proceedings in City of Pompano were brought pursuant to 14 C.F.R. Part 16. See, e.g., 14 C.F.R. §16.1, et seq. Under Part 16, the burden of proof with respect to noncompliance with any act, regulation, order, agreement or document of conveyance is on the Agency.[26] The proponent of any motion, request or order has the burden of proof.[27] Finally, a party who has asserted an affirmative defense has the burden of proving that affirmative defense.[28]
While the party propounding a position will ordinarily have the burden of proof, that is not the case where an airport operator has imposed restrictions on access to the airport. The Director’s determination in City of Pompano Beach made this clear, as the Director declared:
The justification for restrictions should be fully documented. In cases where complaints are filed with FAA regarding an aeronautical use restriction, FAA Office of Airports will make a determination regarding the reasonableness of the restriction. Restrictions imposed for safety and/or efficiency should have supporting justification from FAA Flight Standards and Air Traffic Offices. It may be appropriate for FAA to initiate a safety analysis to assess any safety issues and to conduct an airspace study to determine the efficiency and utility of the airport when considering a proposed restriction [see FAA Order 5190.6A, Airport Compliance Requirements, 4-8(a)(1).]The FAA is the final authority in determining what constitutes a compromise of safety. In addition, FAA will make the final determination on the reasonableness on the airport owner’s restrictions that deny or restrict use of the airport. In making a final determination on safety, FAA must determine whether or not the aeronautical activity being restricted can be safely accommodated on the airport and, therefore, whether the proposed restriction meets the statutory requirements and/or the terms of surplus property deeds of conveyance. It may be necessary for FAA to address whether it is possible to accommodate an aeronautical activity with fewer restrictions than are contemplated.[29]
It is important for the aircraft owner, the aircraft operator or the aeronautical user to understand that when the airport sponsor imposes restrictions on the airport, the airport sponsor has the burden of supporting its position with justification.[30]
In rendering his decision, the Director of Airports noted that the FAA “makes the final determination on the reasonableness of an airport owner’s restrictions that deny or restrict use of the airport.”[31] The Director also noted that the federal government has preempted areas of airspace use and management, air traffic control and aviation safety.[32] The Director noted that while the preemption provisions of 49 U.S.C. §41713(b) is not one of the express authorities listed in 14 C.F.R. §16.1 for Part 16 jurisdiction, the FAA may investigate alleged violations of federal preemption in conjunction with an alleged violation of the airport sponsors federal grant assurance obligations.[33] The Director further noted that the FAA is required to consider whether an airport noise rule “is consistent with the highest degree of safety in air commerce and air transportation, is economically reasonable, technologically practicable and appropriate for the particular type of aircraft.”[34] The Director further noted that Part 36 of the Federal Aviation Regulations provide for three stages of aircraft noise levels, Stage 1, Stage 2, and Stage 3, with new type certificates applied for on or after November 5, 1975, to comply with the Stage 3 noise limits.[35] The Director considered both the Aviation Safety and Noise Abatement (ASNA), 49 U.S.C. §47501, et seq., as well as the Airport Noise and Capacity Act of 1990 (ANCA), 49 U.S.C. §47521 in reaching his decision.[36] Under ASNA, the FAA was required to establish a single system of measuring noise and a single system for determining the exposure of individuals to airport noise resulting from airport operations including noise intensity, duration, frequency, and time of occurrence (citing 49 U.S.C. §47502).[37] The Director further noted that the FAA “has determined that all land uses are compatible with sound levels that are less than DNL 65dB(A) and has designated what land uses are compatible with sound uses higher than DNL 65dB(A), citing 14 C.F.R. Part 150, Appendix A, Part B, Section A150.101(d).[38] The Director in City of Pompano Beach further noted that “[t]he airport operator must provide an adequate opportunity for the public, the affected states and localities, appropriate planning agencies and aeronautical users of the airport to submit comments on the (noise study) plan.[39] The Director further noted that approval of a noise compatibility program does not constitute approval to implement a specific noise compatibility measure.[40]
The Director in City of Pompano Beach concluded: “The administrative record does not include supporting justification from FAA Flight Standards and/or Air Traffic to confirm that stop-and-go operations and intersection takeoff pose an inherent safety hazard or interfere with efficiency.”[41] The Director therefore found that, “The restrictions on stop-and-go operations and intersection take-offs are not justified and cannot be enforced as safety and efficiency restrictions.”[42] The Director, in finding that the airport sponsor had failed to make the airport available to all classes of aeronautical users without unjust discrimination declared:
A complaint has been raised regarding the City’s restrictions on stop-and-go operations and intersection take-offs; these restrictions, based on safety and efficiency, are not supported by justification from FAA Flight Standards and/or Air Traffic. Therefore, the Director cannot accept these restrictions as approved access restrictions based on safety and efficiency concerns. In the absence of the City taking appropriate prompt corrective action, the City faces possible sanctions as described below.[43]
The Director found that the basis for these restrictions to the airport were so-called “noise abatement limitations” contained in ordinance 95-79.[44] The Director quoted from a letter from the FAA Orlando Airports District Manager to the City noting that the airport sponsor had limited authority to determine permissible levels of noise, could not interfere with flight safety or efficiency, and could not unjust single out certain categories of aircraft, such as jet aircraft, general aviation or flight training.[45]
The Director noted that the record before him indicated that five people comprised 57% of the noise complaints while 10 people made up 73% of the noise complaints.[46] The Director commented that individual annoyance does not accurately measure community annoyance.[47]
While noting that a Part 150 study is voluntary, the Director further noted that in interpreting 49 U.S.C. §47107(a)(1) that requires that a federally funded airport be “available for public use on reasonable conditions,” any restriction on access to the airport by the airport sponsor must: “(1) be justified by an existing non-compatible land use problem, (2) be effective in addressing the identified problem, and (3) reflect a balanced approach to addressing the identified problem that fairly considers both local and federal interests.”[48] The Director found: “The City has not provided evidence that it addressed the perceived noise problem using a balanced approach which would take into consideration both local and federal interests…as a result, the noise abatement restriction affecting stop-and-go operations, intersection take-offs, touch-and-go operations, taxi back activity, prolonged running of aircraft engines, and restrictions on rotorcraft are unreasonable and unjustly discriminatory.”[49]
The City of Pompano Beach maintained that since its ordinances were adopted prior to 1990, it was exempt from complying with ANCA even if Part 161 otherwise applied.[50] The Director rejected this argument as relates to a violation of the sponsor grant assurances noting:
Some of the restrictions implemented by the Air Park do not meet the timing guidelines for grandfathering under ANCA if ANCA applies. However, as noted earlier, ANCA issues are not within the purview of this Part 16 review process. Our determination is based on the City’s requirement under its quitclaim deeds to make the airport available on reasonable terms and without unjust discrimination.[51]
The City of Pompano maintained that its ordinance precluding certain operations at certain times of the day did not preclude aircraft owners departing the airport and flying to another airport to accomplish training or maintain currency. The Director rejected this argument noting, “Shifting aeronautical activity from one airport to another impacts the air transportation system.”[52]
The Director found as follows:
…the City is not currently in compliance with the reasonableness and unjust discrimination provisions in the 1947 and 1948 quitclaim deeds executed under the powers and authority contained in the provisions of Surplus Property Act of 1944, as amended, 49 U.S.C. §47152(2), regarding the restricted access for (1) stop-and-go operations, (2) intersection take-offs, (3) touch-and-go operations, (4) taxi-back activity, (5) prolonged engine run-ups, and (6) including rotorcraft in its restrictions.”[53]
The Director required the City to cease enforcement of its safety restrictions on stop-and-go operations and intersection take-offs.[54] The Director further found that restrictions to the airport based upon noise considerations were not justified including (1) stop-and-go operations, (2) intersection take-offs, (3) touch-and-go operations, (4) taxi-back activity, (5) prolonged engine run-ups, and (6) including rotorcraft in the restrictions.[55] The Director placed near the end of his opinion a table to the aeronautical activities, the basis for the restriction, and the basis for the Director’s determination concerning that restriction.[56] While the Director found in favor of the complaining parties as to whether the City of Pompano Beach had violated the grant assurance to make the airport available without unjust discrimination, the Director did not find that the actions of the City of Pompano rose to the level of an exclusive use violation.[57]
[22] Aircraft Owners’ and Pilots’ Association (AOPA) members Bill Bahlke, Reagan L. Dubois, Howard G. Soloff, Lawrence K. Melgrin, David Watkins, Joseph Hawhe, Robert Kwass, Herbert Jacobs, and Levent Erkmen v. City of Pompano Beach, Florida, 2005 WL 3722717 (FAA) (hereinafter “City of Pompano Beach”).
[23] Id. at 1, 3, 4.
[24] Id. at 5, 6.
[26] 14 C.F.R. §16.229(a).
[27] 14 C.F.R. §16.229(b).
[28] 14 C.F.R. §16.229(c).
[29] City of Pompano, supra at 9.
[53] Id. at 37.
The needs of America for a national airspace system and a network of public use airports will not permit local governments to deny access to classes of aircraft based on noise concerns. Subjective impressions of residents living near airports will not afford the airport owner a defense if a complaint is lodged asserting violations of FAA Grant Assurances. A review of 14 C.F.R. Part 150 and the Director’s Determination in City of Pompano Beach, supra, makes that clear. Local government efforts to regulate or restrict access to public airports will invariably fail, since the area is clearly preempted by federal law. Offset against these clear realities one may find a local government which, due to ineptness or political hubris, believes it can restrict access to a public airport based on noise concerns. In those instances, this paper may be of some assistance to lawyers representing aircraft operators and aeronautical users.