Grand Canyon National Park - Overflights - Chronology of Significant Events (U.S. National Park Service)

Event No.	Month	Year	Action/Topic	Additional Action
1	Feb	1919	First air tour overflight of Grand Canyon recorded (February), Grand Canyon National Park created (August).
2		1926	First scenic air tour flights over Grand Canyon from an air strip near Red Butte.
3		1927	First air tour company begins operations.
4		1956	TWA-United mid-air collision over GCNP; 128 fatalities.
5		1967	New airport, "Grand Canyon National Park Airport", built south of Tusayan (3 miles south of park boundary).
6	Jan	1975	Grand Canyon National Park Enlargement Act (PL 93-620) passed. It recognized (1) the potential for adverse impacts from aviation overflights and (2) natural quiet is a resource or value to be protected. It required studies on potential significant adverse effects of overflights to natural quiet and experience of the park.
7	Jun	1986	Mid-air collision between two air tour flights resulted in 25 fatalities and focused national attention on the issue.	Led to passage of Public Law 100-91
8	June	1987	Federal Aviation Administration (FAA) publishes SFAR No. 50 to establish special flight regulations in vicinity of Grand Canyon National Park.
9	Aug	1987	PL 100-91 ("National Parks Overflights Act") passed. It 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	Catalyst for Preparation of NPS Report to Congress on Effects of Aircraft Overflights on The National Park System
10	Jun	1988	The FAA publishes SFAR No. 50-2 to revise flight procedures in Grand Canyon National Park (GCNP) airspace; establishes special flight rules area (SFRA); prohibits flights below a certain altitude (14,499 ft MSL); established four flight-free zones; set special routes for commercial sightseeing operators; and required certain terrain avoidance and communications requirements.
11	Sept	1994	The USDOI - NPS submits "Report on Effects of Aircraft Overflights on the National Park System." The report defined "restoration of natural quiet" as 50 percent or more of the park achieve natural quiet (no aircraft audible) for 75 to 100 percent of the day.	Report is published in July 1995
12	April	1996	The President directs the Secretary of Transportation to issue proposed regulations for GCNP that would appropriately limit sightseeing aircraft to reduce the aircraft noise immediately and to further restore natural quiet, as defined by the Secretary of the Interior, while maintaining aviation safety in accordance with the Overflights Act.
13	Dec	1996	The FAA publishes Final Rules "Special Flight Rules in the Vicinity of GCNP" (SFRA -14 CFR § 93.301) and notice of availability of proposed commercial air tour routes which establishes seasonal flight curfews for east end of GCNP (14 CFR § 93.305); temporary cap on the 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 the airspace route changes and does not implement the cap on the number of air tour aircraft.
14	Dec	1996	The FAA publishes a Notice of Proposed Rulemaking (NRPM), (Notice 96-15) Noise Limitations for Aircraft Operations in the Vicinity of GCNP, proposal which sought to reduce the impact of air tour aircraft by providing an incentive flight corridor through GCNP for noise efficient ("quiet") aircraft; to categorize aircraft by noise efficiency,; and remove the aircraft cap for the most noise efficient aircraft.	The FAA later delays focus on development of quiet technology until April 2000.
15	Dec	1996	FAA is sued over implementation of the Final Rules by Air Tour Industry, delaying further the effective date of portions of the Final Rule (Flight Free zones, flight corridors, and airspace structure.	Implementation of airspace and route structures encounters a series of delays, re-issuance of modifications, and litigation. FAA is later upheld in court decision.
16	Jan	1999	NPS publishes a Federal Register Notice of agency policy "Change in Noise Evaluation Methodology for Air Tour Operations over GCNP." The notice described a two-zone system with different noise thresholds (audibility and noticeability) to be used in modeling the amount of substantial restoration achieved. GCNP refined natural ambient sound zones and added to additional zones.	This evaluation methodology becomes effective in July 1999.
16A	Jan	1999	The NPS publishes in Federal Register (64 FR 3969) of "Evaluation Methodology for Air Tour Operations Over Grand Canyon National Park."
17	July	1999	FAA publishes an NPRM (Notice 99-11) to modify the dimensions of the GCNP SFRA that modifies the eastern portion of the SFRA and Desert View Flight-Free Zone to extend the boundary 5 nautical miles to the East; Modifies the Bright Angel Flight-Free Zone to a possible quiet technology incentive route, and provides for an additional route between Las Vegas and Tusayan; and modifies the northern boundary of the Sanup Flight-free zone.
18	July	1999	FAA publishes an NPRM (Notice 99-12) to limit the number of commercial air tours in the SFRA by proposing --Temporary limits ("allocations") on the number of air tours in the SFRA to the number reported between 5/1/97 and 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 the Dragon or Zuni Point Corridors transfer of allocations out of these corridors is permissible; and no transfer of allocations from "peak" to "off-peak" seasons.
19	July	1999	FAA releases a "Notice of Availability of Routes" The changes include: Elimination of Blue 1 and Blue 1A routes through the National Canyon and Havasupai Reservation areas; Simplifying and shortening west-end routes (Green 4 and Blue 2)and 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 ( FFZs).
20	Feb	2000	FAA delays for second time effective date of 14 CFR §93.301, 93.305, and 93.307 (Quiet Technology).
20	April	2000	FAA Final Rules changed airspace and routes for air tours, set limitations on the number of air tour flights at Grand Canyon (allocations) at 90,000, and added reporting requirements for air tour operators.	This rule went into effect on April 19, 2001.
21	April	2000	The National Parks Air Tour Management Act (P.L. 106-181) is 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, it 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.	FAA delays this task and issues an amendment to (Notice 96-15) in FR 14715, March 2003. It proposes standards for quiet technology.
22	May	2000	The FAA Commercial Air Tour Limitations Final Rule becomes effective this date.
23	Nov	2000	Implementation of airspace and route changes encountered a series of delays, re-issuance of modifications, and litigation. A modified route structure (new routes on the west-end and continuation of previous routes on the east-end) was implemented April 19, 2001.	See August 2002 Court of Appeals decision
24	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 National Parks Overflights Act (Quiet Technology in particular).
25	Dec	2001	FAA issues a Federal Register notice extending the implementation of the airspace modification final rule (66 FR 63294) until February 2003.	This date was again delayed by FAA until 2/20/06 (68 FR 9496).
26	Jan	2002	The U.S. Air Tour Association (USATA) challenged two FAA Final Rules issued in 2000 in the U.S. Court of Appeals in 2002. An environmental coalition led by the Grand Canyon Trust was an intervenor. The USATA sought to have the flight limitations rule set aside largely for procedural reasons. The environmental coalition asked the court to order the FAA to follow the wording of P.L 100-91 and allow the 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"). This suit also asked that all aviation noise be considered, not just noise produced by commercial air tours.
27	Aug	2002	On August 16^th 2002, the U.S. Court of Appeals rejected the challenges brought by the Air Tour Association, but concluded that challenges brought by the Grand Canyon Trust, raised issues that require further consideration by the FAA.
28	Jan	2003	The "Aircraft Noise Model Validation Study" was released by NPS and FAA to public.	Noise Map Simulation Model (NMSIM) is NPS model of choice for Grand Canyon National Park
29	Nov	2003	NPS Federal Register Notices defining the term "the day" and selection of NMSIM as NPS "model of choice" to help determine restoration of natural quiet at Grand Canyon National Park are published.	Federal Register Notice/Vol. 68, No. 216, Nov 7, 2003; pgs 63129-63132
30	Feb	2004	NPS and FAA meet to begin Alternative Dispute Resolution Process (ADR) to resolve/address long standing issues and improve interagency communication.	Lead by U.S. Institute for Environmental Conflict Resolution
31	Nov	2004	NPS and FAA hold first ADR meeting with stakeholders to introduce process and seek participation.	Determine process to be used to arrive at solution to issues
32	Feb	2005	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.
33	Mar	2005	Federal Interagency Committee on Aircraft Noise (FICAN) releases "Assessment of Tools for Modeling Aircraft Noise in the National Parks" and designates INM 6.2 as the model to use for assessing aircraft noise at Grand Canyon and for ATMP parks.	INM 6.2 to be available in 3 to 6 months from FICAN release date (pending funding).
34	Mar	2005	GRCA Overflights begins collecting natural ambient data for use in INM modeling of aircraft noise at the park. Four vegetation types are being sampled which represent 96% of the acreage of the park.	Obtaining summer natural ambient data is for first INM model run to assess progress on achieving substantial restoration of natural quiet.
35	Mar	2005	NPS and FAA announce that the National Parks Overflights Advisory Group (NPOAG) to provide advice, information and recommendations to NPS and FAA on implementation of the National Parks Overflights Act (P.L. 100-91).	NPOAG internal discussion and group acceptance to be involved in ADR process.
36	Mar	2005	FAA issues Final Rule on "Noise Limitations for Aircraft Operations in the Vicinity of Grand Canyon National Park" dated March 29, 2005.	Rule sets decibel levels for "Quiet Technology" aircraft, and classifies aircraft used for tours by the noise they produce. It identifies which aircraft meet or do not meet the GCNP quiet aircraft technology designation.
37	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", dated March 30, 2005.	The NPS and FAA establish a Grand Canyon Working Group within NPOAG, and ask people to assist/nominate representatives to the ADR working group, and identify the role of NPOAG in the ADR process and conflict resolution efforts.
38	July	2005	First meeting of GCNP-Overflights Advisory Group (NPOAG sub-committee)	Introduced members of the working group; discussed meeting protocols and procedures; summarized the history and background of the GCNP overflights issue; and discussed the scope of the working group and a time schedule. Reviewed current efforts on overflights data collection and noise analysis.
39	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.
40	Oct	2005	Second meeting of GCNP-Overflights Advisory Group (NPOAG sub-committee)	Review Tribal consultation requirements; field trip to present GCNP sound systems and the methods used in the collection of natural ambient data. Technical presentations on acoustic data collection, use, and analysis and its use in upcoming aircraft noise model runs in December, 2005. FAA presented air tour data and selection of "Peak Day" for December model runs.
41	Nov	2005	NPS submits to FAA summer natural ambient data for use in FAA’s INM 6.2 model assessment of aircraft noise; Progress towards restoration of natural quiet at GCNP since the 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.