Overflights - Chronology of Significant Events



Additional Action

Feb 1919

First Grand Canyon air-tour overflight recorded (February)

Aug 1919

Grand Canyon National Park created


First Grand Canyon scenic air-tour flights from airstrip near Red Butte


First air tour company begins operations


TWA-United mid-air collision over GCNP; 128 fatalities

Led to establishment of FAA


New Grand Canyon National Park Airport built south of Tusayan (three miles south of park boundary)

Jan 1975

Grand Canyon National Park Enlargement Act (PL 93-620). Whenever an aircraft or helicopter activity or operation is likely to cause injury to the health, welfare, or safety of visitors or cause a significant adverse effect on natural quiet and experience of the park, the Secretary shall submit recommendations for rules and regulations or other actions appropriate to protect public health, welfare, and safety or the natural environment within the park. After reviewing the submission of the Secretary, the responsible agency shall take appropriate action to protect the park and visitors

Sept 1985

GCNP publishes Aircraft Management Preplanning Booklet to prepare public for series of scoping meetings regarding upcoming Aircraft Management Plan Environmental Assessment; booklet contained "a summary of information gathered to date in planning for aircraft management at GCNP. Between October 1984 and July 1985, park representatives conducted a series of meetings with representatives of air tour operators, environmental groups, and aviation regulatory agencies. These meetings were conducted to share information, develop an understanding of the issues, needs, and concerns of each group, and provide a framework for presenting this information for public review."

Led to December 1987 Grand Canyon Aircraft Management Recommendation

May 1986

GRCA publishes Aircraft Management Plan Environmental Assessment; Purpose And Need section states the reasons for developing an Aircraft Management Plan for GCNP are: "1) to meet requirements of the 1916 NPS Organic Act and 1978 Public Law 95-250 [Redwood National Park Expansion Act] 'to conserve' resources of the park and the values and purposes for which the park was established, and 2) to protect the public health, welfare, and safety, and the natural environment within the park, including the natural quiet and experience, as stated in the 1975 GCNP Enlargement Act." In accordance with the above legislation and the NPS planning process, the park has determined aircraft activity occurring over or within the park is currently causing a significant adverse effect on the natural quiet and experience of the park, and that aircraft activity may be likely to cause an injury to the health, welfare, or safety of visitors to the park (GCNP memorandum dated March 10, 1986)."

Jun 1986

Mid-air collision between two air-tour flights. 25 fatalities focused national attention on the issue

Led to passage of Public Law 100-91

Mar 1987

Federal Aviation Administration (FAA) publishes Special Flight Rules Area (SFAR) No. 50 to establish special flight regulations in vicinity of Grand Canyon National Park


FAA modified SFAR 50 by raising the ceiling to 9,000 feet MSL in SFAR 50-1. (52 Federal Register 22734)

Aug 1987

National Parks Overflight Act PL 100-91 passed. Act required

·Analysis of the nature, scope, and effects of overflights in national park units

·Analysis whether SFAR-50 succeeded in substantially restoring natural quiet in the park

·Designation of flight free zones except for administrative and emergency operations

(hereafter called the 1987 Overflights Act)

Catalyst for preparation of NPS Report to Congress on Effects of Aircraft Overflights on the National Park System

Dec 1987

Grand Canyon Aircraft Management Recommendation

Jun 1988

FAA publishes SFAR 50-2 (53 Federal Register 20264) to revise flight procedures in Grand Canyon National Park (GCNP) airspace

· extended the Special Flight Rules Area (SFRA)

· prohibits flights below a certain altitude (14,499 ft MSL)

· establishes four flight-free zones

· sets special routes for commercial sightseeing operators

· requires certain terrain avoidance and communications requirements

March 1994

NPS conducts three-day "Finding A Balance Workshop" in Flagstaff, Arizona with approximately 100 participants to enlist assistance in developing a recommendation to appear in the Report to Congress to improve SRNQ and visitor experience at GCNP

Mar 1994

FAA and NPS jointly issue advanced notice of proposed rulemaking on quiet technology and incentives. (59 Federal Register 12740)

Sep 1994

NPS submits Report to Congress on Effects of Aircraft Overflights on the National Park System. Report defined "restoration of natural quiet" as 50% or more of the park achieves natural quiet (no aircraft audible) 75 to 100% of the day

Report published July 1995

Jun 1995

FAA published a Final Rule that extended the provisions of SFAR 50-2 to June 15, 1997, pending implementation of the Final Rule adopting NPS recommendations for overflights at Grand Canyon

Apr 1996

President Clinton issued a Presidential Memorandum directing the Secretary of Transportation to issue proposed regulations for GCNP to appropriately limit sightseeing aircraft to reduce aircraft noise immediately, and further restore natural quiet, as defined by the Secretary of the Interior, while maintaining aviation safety in accordance with the 1987 Overflights Act (61 Federal Register 18229)

Also required development of plan to complete restoration and maintenance of natural quiet if the Final Rule did not accomplish goal

Dec 1996

FAA publishes (61 Federal Register 69302) Final Rule, Special Flight Rules in the Vicinity of GCNP (SFRA, 14 CFR § 93.301) which establishes

· seasonal flight curfews for GCNP east end (14 CFR § 93.305)

· temporary cap on number of air-tour flights

· air-tour operator's reporting requirement

· changed airspace routes and altitudes for air tour flights (14 CFR §93.307)

FAA later delays implementation of airspace route changes and does not implement cap on number of air-tour aircraft

Dec 1996

FAA publishes (61 Federal Register 69334) a Notice of Proposed Rulemaking (NRPM), (Notice 96-15) Noise Limitations for Aircraft Operations in the Vicinity of GCNP, proposal which sought to

· reduce impact of air-tour aircraft by providing an incentive flight corridor through GCNP for noise efficient (quiet) aircraft

· categorize aircraft by noise efficiency

· remove aircraft cap for the most noise-efficient aircraft

FAA later delays focus on development of quiet technology until April 2000

Dec 1996

FAA publishes a Notice in the Federal Register: Proposed Air Tour Routes for the Grand Canyon National Park, Pages 69356 - 69357 (2 pages) [FR DOC #: 96-33147]

Jan/Feb 1997

FAA sued over December 1996 Special Flight Rules in the Vicinity of GCNP Final Rule implementation. Four groups (Air Tour Coalition, Grand Canyon Trust, Hualapai Tribe, and Clark County Dept. of Aviation) challenged the Final Rule in the Court of Appeals for the D.C. Circuit

FAA is later upheld in court decision

Feb 1997

FAA delayed the effective date for the majority of provisions in the December 1996 Special Flight Rules in the Vicinity of GCNP Final Rule due to safety concerns raised by the operators (62 Federal Register 8862)

This action did not delay curfew, aircraft cap, or reporting requirements. SFAR 50-2 airspace structure and routes remained in effect until future action

May 1997

FAA published (62 Federal Register 26902) a proposed rule to amend two of the flight free zones to establish two quiet technology incentive corridors (Bright Angel FFZ and National Canyon)

Withdrawn on July 1998

Oct 1997

FAA published a Notice of Clarification and reevaluation of the Final Environmental Assessment regarding the December 1996 Special Flight Rules in the Vicinity of GCNP Final Rule aircraft cap. The environmental assessment accompanying the December 1996 Rule used an incorrect number of 136 aircraft in the analysis. Later data showed that 260 aircraft was the correct number that should have been analyzed


After reviewing public comments and consulting with NPS, FAA decided not to proceed with quiet-technology incentive corridors, and withdrew the proposed rule

Sep 1998

The D.C. Circuit denied the petitioners' challenges to the December 1996 Special Flight Rules in the Vicinity of GCNP Final Rule and upheld the portions of the rule in effect, as well as NPS's definition of "substantial restoration of natural quiet"

Jan 1999

NPS publishes a Federal Register Notice (64 Federal Register 3969) of agency policy Change in Noise Evaluation Methodology for Air Tour Operations over GCNP. Notice described a two-zone system with different noise thresholds (audibility and noticeability) to be used in modeling amount of substantial restoration achieved. GCNP refined natural ambient sound zones and added to additional zones

Evaluation methodology becomes effective July 1999


FAA publishes an NPRM (Notice 99-11) to modify GCNP SFRA dimensions that

· modifies the SFRA's eastern portion and Desert View Flight-Free Zone to extend the boundary five nautical miles east

· modifies the Bright Angel Flight-Free Zone to a possible quiet-technology incentive route

· provides for an additional route between Las Vegas and Tusayan

· and modifies the Sanup Flight-free zone's northern boundary


FAA publishes an NPRM (Notice 99-12) to limit number of commercial air tours in the SFRA by proposing

· temporary limits (allocations) on number of SFRA air tours to number reported 5/1/97 to 4/30/98

· new definitions for commercial SFRA operations (transportation, training, maintenance, repositioning, and flights serving Grand Canyon West)

· no transfer of allocations into either Dragon or Zuni Point Corridors transfer of allocations out of these corridors is permissible

· no transfer of allocations from peak to off-peak seasons


FAA releases a Notice of Availability of Routes. Changes include

· elimination of Blue-1 and Blue-1A routes through National Canyon and Havasupai Reservation

· simplifying and shortening west-end routes (Green-4 and Blue-2)

· establishing Blue Direct North and Blue Direct South routes between Las Vegas and Tusayan

· extending Green-3 and Black-4 routes around Bright Angel and Desert View Flight-free Zones

Feb 2000

FAA delays for second time effective date of 14 CFR §93.301, 93.305, and 93.307 (Quiet Technology)

Apr 2000

FAA publishes a Final Rule, Modification of the Dimensions of the Grand Canyon National Park Special Flight Rules Area and Flight Free Zones (65 Federal Register 17736)

· changed airspace and routes for air tours

· only partially implemented due to ensuing litigation

Implementation of airspace and route changes encountered a series of delays, reissuance of modifications, and litigation. Incomplete route structure implemented April 2001

Apr 2000

FAA publishes a Final Rule, Commercial Air Tour Limitation in the Grand Canyon National Park Special Flight Rules Area (65 Federal Register 17708). The rule

· set limitations on number of GCNP air-tour flights (annual allocations) at number flown in the base year defined as beginning on May 1, 1997 and ending on April 30, 1998, except as adjusted to incorporate operations occurring for the base year of April 1, 2000 and ending on March 31, 2001, that operate at or above 14,500 feet MSL and below 18,000 feet MSL

· added air-tour operators reporting requirements

· added Hualapai Exemption (based on temporary economic conditions)

Took effect May 4, 2000. Federal Register notice contains history of actions to this point

Apr 2000

National Parks Air Tour Management Act (P.L. 106-181) passed. §804 of the Act requires FAA "to designate reasonably achievable requirements for fixed-wing and helicopter aircraft necessary... to be considered as employing quiet aircraft technology..."; in addition, Act required a "quiet aircraft technology" definition and creation of incentive routes for quiet aircraft, as long as the routes do not negatively impact substantial restoration of natural quiet, Native American lands, or safety. The Act mandates development of Commercial Air Tour Management Plans (ATMP). Act prohibits a commercial air-tour operator from conducting such tours over a national park or tribal lands, except in accordance with the Act, conditions prescribed for the operator by the FAA administrator, and any commercial air-tour management plan for the park or tribal lands. Finally, Act requires a cooperative relationship between the FAA Administrator and the NPS Director regarding air-tour management planning. Details of a cooperative relationship and the dual-agency process for air tour management planning remain undefined

FAA delays and issues an amendment to Notice 96-15 in FR 14715, March 2003. Proposes standards for quiet technology

Sec. 804(b) of NPATMA requires the FAA Administrator, in consultation with the NPS Director, to establish, by rule, routes and corridors for quiet technology aircraft at GCNP, provided such routes or corridors will not negatively impact SRNQ. Section 804(c) states quiet technology aircraft will not be subject to operational flight allocations that apply to other air-tour operations at GCNP, provided the cumulative impact of such operations does not increase noise at GCNP. Finally, Sec. 804(e) declares nothing in NPATMA shall be construed to relieve or diminish the statutory mandate imposed by the Overflights Act to achieve SRNQ and experience. GCNP exempted from other provisions of Act

May 2000

FAA Commercial Air Tour Limitations Final Rule becomes effective

May 2000

U.S. Air Tour Association (with seven air-tour operators) and Grand Canyon Trust challenge the two April 2000 Final Rules

Nov 2000

Implementations of airspace and route changes encounter series of delays, re-issuance of modifications, and litigation. Incomplete route structure (new routes implemented on West End as proposed in 2000 Final Rule, but East End routes remain unchanged due to safety challenge)

See August 2002 Court of Appeals decision. West End route changes implemented April 19, 2001

Mar 2001

NPS and FAA establish the National Parks Overflights Advisory Group (NPOAG) to provide advice, information and recommendations to NPS and FAA on implementation of the 1987 Overflights Act (Quiet Technology in particular)

Dec 2001

FAA issues a Federal Register Notice delaying implementation of East End airspace modification Final Rule (66 Federal Register 63294) until February 2003

Date later delayed again by FAA until 2/20/06 (68 Federal Register 9496) and again until 2011

Jan 2002

U.S. Air Tour Association (USATA) challenges the two FAA Final Rules issued in 2000 in U.S. Court of Appeals. Environmental coalition led by Grand Canyon Trust was intervener. USATA sought to have the 2000 rule (flight limitations) set aside largely for procedural reasons. Environmental coalition asked court to order FAA to follow wording of P.L 100-91 and allow NPS to define key statutory terms (e.g., to measure substantial restoration of natural quiet on an "any day" rather than an "average annual day"). Suit also asked all aviation noise be considered, not just noise produced by commercial air tours

Aug 2002

U.S. Court of Appeals rejected challenges brought by the U.S. Air Tour Association, but concluded challenges brought by Grand Canyon Trust raised issues requiring further consideration by FAA. The court ruled FAA's use of an annual average day for measuring substantial restoration of natural quiet appeared inconsistent with NPS definition. The court also held FAA must account for noise from aircraft other than air tours when analyzing environmental impacts

Jan 2003

Aircraft Noise Model Validation Study released by NPS and FAA to public

· Noise Map Simulation Model (NMSIM) NPS model of choice for GCNP

Nov 2003

NPS Federal Register Notices published defining term "the day" and selection of NMSIM as NPS "model of choice" to help determine restoration of natural quiet at GCNP. Federal Register Notice/Vol. 68, No. 216, Nov 7, 2003; pgs 63129-63132

Feb 2004

NPS and FAA, under the auspices of NPOAG, meet to begin Alternative Dispute Resolution (ADR) process to resolve/address long-standing issues and improve interagency communication. Lead by U.S. Institute for Environmental Conflict Resolution

Nov 2004

Under the auspices of NPOAG, NPS and FAA hold first ADR meeting with stakeholders to introduce process and seek participation. Determine to arrive at solution to issues

Feb 2005

Under the auspices of NPOAG, NPS and FAA hold second ADR meeting to outline process of participant selection, roles, and ADR schedule of progress. Selection of Action Committee composed of NPOAG members and ADR participants, to make recommendations on ADR steps

Grand Canyon Working Group established by NPOAG

Mar 2005

Federal Interagency Committee on Aircraft Noise (FICAN) releases Assessment of Tools for Modeling Aircraft Noise in National Parks and designates Integrated Noise Model (INM) 6.2 as the model to be used for assessing aircraft noise at GCNP and parks requiring Air Tour Management Plans

INM 6.2 available 3 to 6 months from FICAN release date (pending funding)

Mar 2005

GRCA Overflights Program begins collecting natural ambient data for use in park INM aircraft-noise modeling. Four vegetation types are sampled which represent 96% of park acreage. Obtaining summer natural ambient data for first INM model run to assess progress on achieving substantial restoration of natural quiet

Mar 2005

FAA issues Final Rule on Noise Limitations for Aircraft Operations in the Vicinity of Grand Canyon National Park (70 Federal Register 16084)

· Rule sets decibel levels for quiet-technology aircraft, and classifies tour aircraft by noise produced. Identifies which aircraft meet or do not meet GCNP quiet-aircraft technology designation

Mar 2005

NPS and FAA issue notice for Membership in the Grand Canyon Working Group of the National Parks Overflights Advisory Group Aviation Rulemaking Committee

· NPS and FAA establish Grand Canyon Working Group within NPOAG, ask people to nominate representatives to the ADR working group, and identify NPOAG role in ADR process and conflict-resolution efforts


First meeting of GCNP Overflights Working Group (NPOAG sub-committee). Additional meetings

2005 Jul 13-14;
Oct 26-27
Flagstaff AZ;
Tusayan AZ
2006 Jan 31-Feb 2;
Mar 20-22;
May 31-Jun 2;
Jul 25-27;
Sep 27-28;
Dec 12-13
Phoenix AZ;
Las Vegas NV;
Scottsdale AZ;
Phoenix AZ;
Phoenix AZ;
Scottsdale AZ
2007 Jun 12-13; Sep 19-20;
Dec 4-5
Scottsdale AZ
2009 Jul 28 Flagstaff AZ
Reviewed current efforts on overflights data collection and noise analysis; discussed various Alternatives and elements; issues and topics related to overflightstd>

Aug 2005

Summer natural ambient data collected for analysis and use in upcoming model runs to assess restoration of natural quiet at GCNP

To be presented at next NPOAG sub-committee meeting. Natural ambient data collection continues

Nov 2005

NPS submits to FAA summer natural ambient data for use in FAA's INM 6.2 model assessment of aircraft noise; Progress toward restoration of natural quiet at GCNP since enactment of Special Flight Rules Area 50-2 regulations (2000) to be modeled

Modeling of aircraft noise at GCNP to occur in December, with results expected in January 2006

Jan 2006

NPS and the FAA publish a Notice of Intent (71 Federal Register 4192) to prepare this Environmental Impact Statement

Feb 2006

FAA issues a Final Rule (71 Federal Register 09439) that further delays implementation of airspace and commercial air-tour route East End changes until February 20, 2011

· Stays effective date for Airspace Modification Final Rule implementation for East End until February 20, 2011. In a case decided in August 2002, the U.S. Court of Appeals for the District of Columbia Circuit returned GCNP rules to FAA for further consideration of ways to ensure substantial restoration of natural quiet. After several attempts in resolving the East End routes issue, in February 2003, FAA stayed East End routes and airspace changes until February 20, 2006. Because of an ongoing mediation action, which involves consideration of East End routes, FAA finds it necessary to extend the date for the effectiveness until February 20, 2011

NPS and FAA, the U.S. Institute for Environmental Conflict Resolution (under contract), and involved park stakeholders, consider additional measures to be incorporated into an overflights plan

Implementation of airspace and commercial air-tour route East End changes delayed until February 20, 2011primarily due to safety concerns raised with FAA

May 2006

Government Accounting Office publishes report, National Parks Air Tour Fees: Effective Verification and Enforcement Are Needed to Improve Compliance, GAO-06-468

Apr 2008

NPS publishes a Federal Register notice (73 Federal Register 55130) clarifying definition of SRNQ at GCNP

· will be achieved when reduction of noise from aircraft operations below 18,000 feet MSL results in 50% or more of the park achieving restoration of natural quiet (i.e., no aircraft audible) for 75 to 100% of the day, each and every day. 50% restoration is defined as a minimum goal

Sept 24 2008

Public Notice Clarifying the Definition of Substantial Restoration of Natural Quiet at Grand Canyon National Park, AZ 73 FR 55130

· On April 9, 2008, NPS published a Public Notice of agency policy in the Federal Register with the above title (73 FR 19246-19248), clarifying the NPS definition of SRNQ at GCNP to distinguish between aircraft noise generated above and below 17,999 feet MSL, and requesting comments on the proposed clarification. The public comment period was open April 9 to May 9, 2008. NPS received and analyzed 127 comments in response to the Public Notice. Comments were received from the National Air Transportation Association; environmental groups (e.g., Sierra Club, Audubon Society, and Grand Canyon Trust); air tour operators; and the general public. Comments beyond the scope of this clarification may be considered in development of the Environmental Impact Statement for Special Flight Rules in the Vicinity of Grand Canyon National Park (EIS)


Resolution between DOT and DOI delineating FAA and NPS responsibilities for the EIS process signed January, 2011

Feb 2011

Planned implementation of airspace and commercial air-tour route East End changes deferred until February 20, 2011 by FAA in the 2006 Final Rule (71 Federal Register 09439) go unimplemented.

Changes deferred to this planning process


DEIS Notice of Availability posted by EPA in the Federal Register (February 18, 2011). 76 FR 9575.

Feb 2011

NPS releases Special Flight Rules Area in the Vicinity of Grand Canyon National Park Draft Environmental Impact Statement

120-day public comment period

June 2011

Formal 120-day public comment period ending June 20, 2011. Public meetings to provide DEIS overview and accept public comment held in Phoenix and Flagstaff, Arizona, and Henderson, Nevada, and attended by 174 people. Press releases, website updates, and public meetings used to request public input and disseminate information about DEIS Alternatives and impacts.

June 2012

The National Park Service and Federal Aviation Administration have been working together to substantially restore natural quiet and improve visitor experience at Grand Canyon National Park since the passage of the 1987 National Park Overflights Act. That Act was passed 25 years ago, August 18th.

The National Park Service had expected to issue a final environmental impact statement earlier this summer; however, language in the surface transportation bill impacted that effort. The National Park Service did release a draft environmental impact statement in early 2011 and received approximately 30,000 comments, most of which favored additional protections for park resources and visitor experience.

The National Park Service is currently analyzing recently approved provisions in the surface transportation reauthorization bill (Public Law 112-141; MAP-21) to determine how they will affect Grand Canyon National Park's overflights planning effort. Once that analysis has been completed, the National Park Service will determine how best to be responsive to the legislation, while completing the plan.

Last updated: February 24, 2015

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