[Federal Register Volume 80, Number 77 (Wednesday, April 22, 2015)]
[Notices]
[Pages 22606-22611]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-09380]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

DEPARTMENT OF THE INTERIOR

National Park Service

[Docket No. FAA-2014-0782]


Grand Canyon National Park Quiet Aircraft Technology Incentive: 
Seasonal Relief From Allocations in the Dragon and Zuni Point Corridors

AGENCY: Federal Aviation Administration, Transportation; National Park 
Service, Interior.

ACTION: Final notice to announce implementation and disposition of 
public comments.

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SUMMARY: On November 10, 2014, the Federal Aviation Administration 
(FAA) and the National Park Service (NPS) published in the Federal 
Register [79 FR 66763-66765] a notice of the agencies' proposal to 
provide a quiet aircraft technology incentive for commercial air tour 
operators at Grand Canyon National Park and a request for public 
comments. Specifically, the agencies proposed to provide seasonal 
relief from allocations in the Dragon and Zuni Point corridors for 
commercial air tour operators that convert or have converted to quiet 
aircraft technology. The FAA and the NPS have reviewed and considered 
all comments, and have decided to proceed with implementation of the 
incentive as proposed. This notice describes that decision and responds 
to the substantive comments received.

DATES: This incentive is effective as of January 1, 2015.

FOR FURTHER INFORMATION CONTACT: Keith Lusk, Program Manager, Federal 
Aviation Administration, P.O. Box 92007, Los Angeles, California 90009-
2007; telephone (310) 725-3808; email [email protected] Robin Martin, 
Chief, Office of Planning and Compliance, Grand Canyon National Park, 
P.O. Box 129, Grand Canyon, Arizona 86023-0129; telephone (928) 638-
7684; email [email protected].

SUPPLEMENTARY INFORMATION:

I. Authority

    Authority: Moving Ahead for Progress in the 21st Century Act, 
Sec. 35001, Pub. L. 112-141, 126 Stat. 843; National Parks Air Tour 
Management Act, Sec. 804, Pub. L. 106-181, 114 Stat. 192.

    1. The National Park Overflights Act of 1987, Pub. L. 100-91, 
directed the Secretary of the Interior and the Administrator of the FAA 
to take actions to provide for the substantial restoration of the 
natural quiet and experience of Grand Canyon National Park and the 
protection of public health and safety from adverse effects associated 
with aircraft overflight. As part of these actions, operational limits 
for commercial air tour operations at Grand Canyon National Park (the 
park) were imposed by FAA regulations at 14 CFR part 93 issued on April 
4, 2000. With some exceptions not relevant to this notice, these 
regulations establish an allocation scheme for the park, require 
commercial air tour operators to use one allocation for each flight 
that is a commercial air tour, and prohibit operators from conducting 
more commercial air tours in any calendar year than the number of 
allocations specified on the certificate holder's operations 
specifications issued by the FAA. 14 CFR 93.319.
    2. The National Parks Air Tour Management Act (NPATMA), Pub. L. 
106-181, was signed into law on April 5, 2000. Section 804(a) required 
the FAA to designate reasonably achievable requirements for fixed-wing 
and helicopter aircraft to be considered quiet aircraft technology (QT) 
for purposes of the statute's provisions. In 2005, the FAA issued a 
final rule classifying aircraft operating in Grand Canyon National Park 
and designating aircraft that meet the noise criteria as QT. 70 FR 
16084-16093. These regulations were codified at 14 CFR 93.303 and 
Appendix A to Subpart U of Part 93. Under NPATMA section 804(c), 
commercial air tour operations by fixed-wing or helicopter aircraft 
that employ QT and that replace existing aircraft are not subject to 
the operational flight allocations that apply to other commercial air 
tour operations at the park, provided that the cumulative impact of 
such operations does not increase noise at the Grand Canyon. Section 
804(d) provides that a commercial air tour operation by an aircraft in 
a commercial air tour operator's fleet on the date of enactment of 
NPATMA that meets QT requirements or is subsequently modified to meet 
QT requirements may be used for commercial air tour operations under 
the same terms and

[[Page 22607]]

conditions as section 804(c) without regard to whether it replaces an 
existing aircraft. In addition, NPATMA expressly states that it does 
not relieve or diminish the statutory mandate to achieve substantial 
restoration of natural quiet and experience at the park.
    3. Section 35001 of the Moving Ahead for Progress in the 21st 
Century Act (MAP-21), Pub. L. 112-141, July 6, 2012, directs the 
Secretary of the Interior and the Administrator of the Federal Aviation 
Administration to provide incentives for commercial air tour operators 
that convert to QT, determined in accordance with the regulations then 
in effect. MAP-21 gives as an example of an incentive increasing the 
flight allocations for operators of QT on a net basis consistent with 
section 804(c) of NPATMA, provided that the cumulative impact of such 
operations does not increase noise at the Grand Canyon. MAP-21 also 
provides that all commercial air tour operators must convert to QT by 
2027.

II. Background

    Congress has encouraged the use of quiet aircraft technology (QT) 
as one means of addressing noise from commercial air tours at Grand 
Canyon National Park. The FAA was required by NPATMA to designate 
reasonably achievable requirements for fixed-wing and helicopter 
aircraft to be considered QT, and issued a final rule to accomplish 
this in 2005. This rule did not include QT incentives and did not 
relieve commercial air tour operators of their operational limitations. 
NPATMA's provision that allocations do not apply to QT operations only 
takes effect if the cumulative impact of such operations does not 
increase noise at the Grand Canyon. Although the FAA concluded that 
aircraft that meet the QT designation are consistently quieter than 
aircraft that do not, 70 FR 16088, neither the FAA nor the NPS had 
sufficient data at that time to determine whether noise would increase 
if limits on the number of QT operations were removed. In addition, 
NPATMA expressly states that it does not relieve or diminish the 
statutory mandate to achieve substantial restoration of natural quiet 
and experience at the park. Substantial restoration of natural quiet 
had not been determined to be achieved at that time. Various QT 
incentives were considered by the agencies following the 2005 final 
rule, but were not finalized.
    MAP-21, enacted in July 2012, provided additional direction to the 
FAA and the NPS on QT incentives. In response to MAP-21, the NPS, in 
consultation with the FAA, reduced the fees applicable to commercial 
air tour operations at the Grand Canyon by 20 percent (from $25 to $20 
per flight) for an air tour using QT effective January 1, 2014. On 
February 3, 2014, the FAA, in consultation with the NPS, announced its 
intention to distribute FAA-held allocations to commercial tour 
operators in proportion to the number of QT operations flown in the 
first six months of 2014. 79 FR 6267-6268. These allocations were 
subsequently distributed for use for QT flights during the 2014 air 
tour season and beyond.

III. Seasonal Relief From Allocations for QT in the Dragon and Zuni 
Point Corridors

    Following notice and public comment, the FAA and the NPS have 
decided to provide an additional QT incentive in the Dragon and Zuni 
Point corridors where QT can have the greatest positive effect on park 
resources and where the need for relief from allocations has been 
demonstrated. Under this incentive, commercial air tour operators 
flying QT aircraft in the Dragon and Zuni Point corridors initially 
will be relieved from having such operations count against their annual 
allocations in the first quarter (January 1-March 31) of 2015. The FAA 
and the NPS will use the quarterly reports that are currently required 
to be submitted by the operators to determine the number of QT flights 
flown during the first quarter that will not count against their annual 
allocations. During this first quarter, QT flights will not use an 
allocation, while non-QT flights must still use an allocation. All 
commercial air tour flights, QT and non-QT, must use an allocation for 
the remainder of the year (April 1-December 31). However, operators 
will continue to benefit from the seasonal relief throughout the 
remainder of the year since they may use allocations in April through 
December that they would otherwise have used for QT flights conducted 
in January through March.
    The first quarter of the calendar year, when park visitation and 
demand for air tours are seasonally low, has historically had the 
lowest level of commercial air tour operations. Providing this 
incentive initially in the first quarter of 2015 is a prudent action 
that gives the FAA and the NPS an opportunity to evaluate the impact of 
the incentive, including the extent to which commercial air tour 
operators continue to use QT in the remainder of the year which will 
produce additional noise benefits for the park. The FAA and the NPS 
want to incentivize commercial air tour operators to maximize the use 
of QT throughout the year. To that end, the seasonal relief from 
allocations may be extended to part or all of the fourth quarter 
(October 1-December 31) in 2016 and following years, in addition to the 
first quarter, based on an evaluation of the preceding year. In 2015, 
the more that increased QT use reduces the noise level below the noise 
baseline described in the following paragraph, the greater the prospect 
for operators to have additional seasonal relief from allocations in 
2016.
    To meet the statutory conditions in NPATMA and MAP-21, the FAA and 
the NPS must ensure that the cumulative impact of QT operations 
relieved from allocations does not increase noise at the park. Neither 
NPATMA nor MAP-21 specifies a methodology for calculating whether the 
cumulative impact of relieving QT operations from allocations would 
increase noise. After extensive consideration of the statutory language 
and the associated technical issues, the FAA and the NPS have 
determined that, for this seasonal relief incentive, the annual noise 
from both QT and non-QT commercial air tour flights conducted in the 
Dragon and Zuni Point corridors must not exceed the annual noise level 
of commercial air tour flights under the current Dragon and Zuni Point 
corridors allocation system.
    The agencies have agreed that the cumulative noise impact \1\ will 
be evaluated in terms of the total amount of commercial air tour noise 
energy occurring inside park boundaries averaged over an entire year. 
The agencies further agreed that the most suitable way to ensure that 
the seasonal relief from allocations incentive for QT operations in the 
Dragon and Zuni Point corridors does not increase noise in the park is 
to compute noise at a large number of grid points throughout the park, 
instead of only using grid points in the Dragon and Zuni Point 
corridors. Accordingly, the NPS and the FAA used a grid of 1224 points 
with 2 km spacing across the park. Technical experts from both agencies 
also determined that a single number provides the most straightforward 
means of determining whether there is an increase in noise. This number 
is calculated by taking the total noise energy calculated for a year's 
air tour data at each of the individual grid points and averaging it 
over the entire park--resulting in a single LEQ12 value.\2\
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    \1\ Cumulative noise impact is not the same criterion as the 
substantial restoration of natural quiet (SRNQ). SRNQ is calculated 
and determined on the peak day of air tour operations using the 
percent time audible metric.
    \2\ LEQ12 stands for Equivalent Sound Level for 12 
hours, which is a cumulative measure of the noise exposure of A-
weighted sound levels over a 12-hour period. LEQ12 is one 
of several metrics used to evaluate air tour noise in Grand Canyon 
and other national parks. The metric takes into account aircraft 
noise levels, the number of aircraft operations, and the duration of 
noise. A 12-hour LEQ is used since air tour operations occur during 
the day, rather than over a 24-hour period.

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[[Page 22608]]

    Using this methodology, the FAA and the NPS have modeled the annual 
noise of commercial air tour allocations in the Dragon and Zuni Point 
corridors as flown with the 2012 commercial air tour fleet mix and 
route structure--resulting in a noise baseline of LEQ12 58.1 
decibels (dB). This single number serves as a reference criterion for 
measuring changes to the noise environment based on the cumulative 
impact of operations. It is the average noise level across the entire 
park as if a year's worth of flight allocations in the Dragon and Zuni 
Point corridors took place in twelve hours on a single day. It is not 
intended to represent a value which may be experienced by visitors to 
the park on any particular day.\3\
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    \3\ This LEQ12 value is not an average day noise 
level. To produce a noise level representing an average day at an 
average location in the park, further calculations of the 2012 
LEQ12 58.1 dB value would need to be made and would 
produce an LEQ12 average day noise level of 32.5 dB.
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    A more detailed technical description of the methodology and 
calculations that resulted in the LEQ12 58.1 dB reference 
criterion has been placed in the docket. In order to accurately and 
reliably ensure compliance with the statutory mandate that the 
cumulative impact of operations under this QT incentive not increase 
noise at the park, the same calculation described above will be applied 
to each year's air tour data. The FAA and the NPS will model the annual 
noise from all commercial air tour operations conducted in the Dragon 
and Zuni Point corridors and compare the annual noise with the seasonal 
relief incentive in place with the noise baseline of all commercial air 
tour allocations in these corridors. Noise will be determined to 
increase if the annual modeled LEQ12 noise of commercial air 
tour operations conducted in the Dragon and Zuni Point corridors 
exceeds LEQ12 58.1 dB in the park. If noise in any year 
exceeds the noise baseline, the seasonal relief incentive will be 
modified or discontinued as determined necessary to comply with the 
statutory condition.
    To ensure that this incentive will not diminish the achievement of 
substantial restoration of natural quiet and experience at the park, 
all commercial air tour aircraft including QT must adhere to the 
existing route structure throughout the park, including the Dragon and 
Zuni Point corridors. Substantial restoration of natural quiet in the 
park will continue to be calculated based on the peak day of air tour 
operations using the percent time audible metric. The NPS will continue 
to monitor noise to evaluate substantial restoration of natural quiet.
    This incentive applies only to commercial air tour operators that 
have allocations in the Dragon and Zuni Point corridors; i.e., 
operators must have allocations in these corridors in order to be 
relieved from allocations. It does not apply elsewhere in the Grand 
Canyon Special Flight Rules Area (SFRA). There is an ample unused 
surplus of commercial air tour allocations in the SFRA outside of the 
Dragon and Zuni Point corridors; therefore, operators conducting air 
tours in these other SFRA areas do not need relief from allocations and 
would not be incentivized to convert to QT by a seasonal relief 
incentive.
    Seasonal relief from allocations is intended to provide an 
incentive for operators with non-QT aircraft to convert to QT in 
advance of the statutory requirement for full QT conversion, and to 
maximize use of QT already in the fleet. It rewards those operators who 
have already fully converted to QT by allowing them to take full 
advantage of the incentive. The number of air tours conducted by 
operators using QT can increase beyond the level permitted under the 
existing allocation system as long as the cumulative impact of the 
additional number of quieter aircraft operating in the park does not 
increase noise at the park.
    Seasonal relief from allocations will not automatically increase 
the number of flights. Any increase in air tour flights will depend on 
the demand for air tours, which is influenced by factors such as 
general economic conditions and the amount of tourism. Seasonal relief 
allows air tour operators to save allocations that would have been used 
in the first quarter of the year and to use them during times of year 
when air tour demand is higher. The most immediate effect of the 
incentive is likely to be to provide a cushion of allocations to any 
qualifying operator in the Dragon and Zuni Point corridors that is at 
risk of running out of allocations before the end of the calendar year.
    If the seasonal relief in the Dragon and Zuni Point corridors is a 
successful QT incentive, it is proposed to remain in effect unless it 
violates the statutory condition that the cumulative effect of such 
operations must not increase noise at the Grand Canyon, or diminishes 
the achievement of substantial restoration of natural quiet, in which 
case it will be either modified or discontinued; or until a longer term 
approach for managing air tour noise in the park is in place.
    The FAA and the NPS commit to developing a long term approach for 
managing noise in the park in an expeditious manner. Any long term 
approach will continue to incentivize conversion to QT and will not 
penalize earlier conversion to QT realized through the seasonal relief 
incentive.

IV. Discussion of Comments

    The public comment period was open until December 10, 2014. The FAA 
and the NPS received 147 comments on the November 10, 2014 notice 
describing the proposal to provide seasonal relief from allocations in 
the Dragon and Zuni Point corridors, including 60 comments which were 
posted after the close of the comment period. Commenters included 
individuals identifying themselves as hikers, backpackers, river 
rafters and back-country visitors to the Grand Canyon; groups 
representing those types of park users; environmental and conservation 
organizations (collectively referred to as ``recreational and 
environmental interests''). Joint comments were filed by a helicopter 
trade association and a coalition of Grand Canyon air tour operators 
(collectively referred to as ``air tour interests''). Most of the 
comments expressed appreciation for the unique qualities of the Grand 
Canyon, including natural quiet, and the desire that these qualities be 
protected. The agencies reviewed and considered all comments, and have 
responded below to comments of substance on the QT seasonal relief 
incentive. Comments and responses are organized under subject matter 
headings.

Statutory Basis for Incentives

    Comment: Several commenters representing recreational and 
environmental interests questioned the authority for QT incentives and 
expressed concern about the consistency of this seasonal relief 
incentive with other laws protecting national parks. The air tour 
interests offered their view of Congressional intent and criticized the 
agencies for delay in implementing the legislative directive.
    FAA and NPS Response: This QT incentive is offered pursuant to MAP-
21 and to implement Section 804(c) of NPATMA, as described in this 
notice. MAP-21 and NPATMA include protections to Grand Canyon National 
Park, namely that the cumulative impact of QT operations relieved from 
allocations must not increase noise at the park and that the 
achievement of substantial restoration of natural quiet

[[Page 22609]]

and experience at the park shall not be relieved or diminished. This 
latter provision in NPATMA ensures that this QT incentive is consistent 
with the mandate in the 1987 Overflights Act to achieve substantial 
restoration of natural quiet. Further, the NPS has an affirmative 
responsibility to protect the resources and values of national park 
units, including park soundscapes. To that end, since this measure 
provides incentive for air tour operators and owners to improve their 
fleets commensurate with industry advancements in quiet aircraft 
technology, this incentive holds promise for the continual reduction of 
noise in Grand Canyon National Park. The FAA and the NPS describe the 
history of events that affected the time line of QT incentives in the 
Background section of this notice.

Quiet Technology Incentives

    Comment: Commenters questioned whether the proposed incentive is 
necessary in light of other incentives and the fact that operators are 
already converting to QT. Some commenters representing recreational and 
environmental interests objected to what they view as subsidizing a 
private industry and suggested that operators should pay the cost of 
converting to QT. The air tour interests noted that over $200 million 
has been invested in QT aircraft by the air tour industry.
    FAA and NPS Response: Both NPATMA and MAP-21 contemplate allowing 
increased flights, i.e., relief from allocations or operational caps, 
by QT. This incentive addresses those provisions, i.e., it creates an 
incentive for air tour operators to maximize use of QT aircraft by 
allowing them to fly additional air tours beyond their current 
allocations. Operators are financially responsible for the aircraft 
they use for air tours and have already acquired a significant number 
of QT aircraft at their own cost. MAP-21 requires all commercial air 
tour aircraft operating in Grand Canyon National Park to fully convert 
to QT not later than 2027.
    Comment: Some commenters representing recreational and 
environmental interests suggested the proposal actually gives an 
incentive to retain and operate noisier helicopters. The air tour 
interests commented that operators already need to maximize use of QT 
to recoup costs.
    FAA and NPS Response: Air tour operators that have already 
converted to QT aircraft will have an additional incentive to maximize 
use of those aircraft; other operators will have an incentive to 
convert to QT. Because the cumulative impact of the incentive will be 
evaluated based on the annual commercial air tour operations conducted 
in the Dragon and Zuni Point corridors, the use of QT aircraft at any 
time of the year will contribute to a determination that noise has not 
increased and will increase the potential for the incentive to be 
continued and extended to the fourth quarter in subsequent years.
    Comment: Commenters questioned the basis for classifying aircraft 
as QT and asked who would validate aircraft in an air tour operator's 
fleet as QT.
    FAA and NPS Response: Appendix A to Subpart U of 14 CFR part 93 
contains the procedures for determining the QT designation status for 
each aircraft. Additional guidance can be found in the FAA's Advisory 
Circular 93-2, Noise Levels for Aircraft used for Commercial Operations 
in Grand Canyon National Park Special Flight Rules Area. The FAA is 
responsible for designating aircraft as QT and for determining which 
aircraft comply with that designation.
    Comment: Some commenters suggested that air tour operators should 
be required by regulations to use QT aircraft all of the time or 
convert over a period of time, while others called for a transition as 
soon as possible to QT.
    FAA and NPS Response: MAP-21 requires all commercial air tour 
aircraft operating in the Grand Canyon National Park Special Flight 
Rules Area to fully convert to QT not later than 2027. In the meantime, 
MAP-21 directs the FAA and the NPS to provide QT incentives to 
encourage earlier conversion and use of QT.
    Comment: Some commenters representing recreational and 
environmental interests suggested that flights using ``saved'' 
allocations should use QT. Other commenters suggested that each QT 
flight should use a fraction of an allocation.
    FAA and NPS Response: The agencies structured this incentive to be 
consistent with the NPATMA Sec. 804(c) provision relieving commercial 
air tour operations by QT from operational flight allocations, subject 
to protections with respect to noise and substantial restoration of 
natural quiet in the park, and with the MAP-21 provision that 
references increasing flight allocations consistent with NPATMA Sec. 
804(c). Neither NPATMA nor MAP-21 requires additional conditions to be 
placed on flights using allocations, as suggested by commenters. As a 
practical matter, the FAA expects an air tour operator's fleet to 
include the same proportion of QT for an entire year that it uses in 
the first quarter of the year, which means that QT would be used for 
allocations. Furthermore, the overall air tour activity in the Dragon 
and Zuni Point corridors, whether using QT or non-QT, cannot increase 
noise at the park.
    Comment: Some commenters representing recreational and 
environmental interests advocated a 1-2 year trial period for the 
incentive that expires on date certain. The air tour interests 
suggested that the incentive include the fourth quarter at the outset.
    FAA and NPS Response: The agencies have determined that providing 
this incentive initially in the first quarter of the year is a prudent 
action that gives the FAA and the NPS an opportunity to evaluate the 
noise impact of the incentive, which will depend not only on the first 
quarter QT use but also on the extent to which commercial air tour 
operators continue to use QT in the remainder of the year. The 
incentive may be modified or discontinued as determined necessary to 
comply with the statutory condition at the end of the first year or any 
subsequent year.

Noise Calculation and Impact

    Comment: Some commenters were uncertain as to what the 
LEQ12 58.1 dB metric represents and asked how the baseline 
was developed.
    FAA and NPS Response: The LEQ12 58.1 decibels (dB) 
reference criterion is a basis for judging changes to the noise 
environment, and is not intended to represent a value which may be 
experienced by visitors to the park on any particular day. Additional 
information has been provided in this final notice, and a more detailed 
technical description of the LEQ12 58.1 dB reference 
criterion, including how it was calculated, has been placed in the 
docket.
    Comment: Some commenters representing recreational and 
environmental interests disagreed with using a cumulative metric or 
annual average and said that noise increases should be measured based 
on peak day or each and every day. Commenters also suggested that 
supplemental noise metrics be considered.
    FAA and NPS Response: The statutory language ``cumulative impact of 
such flights'' calls for a metric that calculates noise cumulatively 
over a period of time. LEQ12 is one of several metrics that 
is used to evaluate air tour noise in Grand Canyon and other national 
parks and was selected by technical experts in the FAA and the NPS as 
the most appropriate to use to determine cumulative impact. A daily 
noise calculation is not appropriate for this purpose. Substantial 
restoration of natural quiet, another required criterion,

[[Page 22610]]

will continue to be calculated based on the peak day of air tour 
operations using the percent time audible metric.
    Comment: One commenter suggested that the annual evaluation of the 
incentive's impact should reflect conversion to any QT aircraft that 
produces more noise than an aircraft in the baseline.
    FAA and NPS Response: The annual evaluation will calculate the 
noise of all QT and all non-QT aircraft and will account for any 
additional noise, whether from a noisier aircraft or from more aircraft 
operations.
    Comment: Commenters questioned the baseline against which the 
cumulative impact of QT operations will be compared (i.e., the annual 
noise of commercial air tour allocations in the Dragon and Zuni Point 
corridors as flown with the 2012 commercial air tour fleet mix and 
route structure). Commenters representing recreational and 
environmental interests suggested there should be an improvement in the 
noise level over the status quo measured by actual operations rather 
than allocations. The air tour interests questioned use of a 2012 fleet 
mix rather than a fleet mix representative of either the year 2000 or 
2005 and suggested that the comparison should be to sound levels that 
would have been present if all aircraft were non-QT. The air tour 
interests also suggested that the baseline should be substantial 
restoration of natural quiet.
    FAA and NPS Response: Both NPATMA and MAP-21 include the QT 
limiting provision: ``. . . provided that the cumulative impact of such 
operations does not increase noise . . .'' at the park. Neither statute 
provides for further reductions in noise with respect to QT incentives. 
The prohibition on increasing noise is not defined or elaborated on in 
either statute. The FAA and the NPS considered various possible 
baselines and determined that the baseline should reflect the amount of 
noise that can be generated by the number of commercial air tour 
operations that are permitted under the current allocation system. If 
noise exceeds a level that is currently permitted under the allocation 
system, the agencies will consider it to be an increase in noise. The 
alternative selection of a noise baseline using the actual level of air 
tour operations in 2012, as recreational and environmental interests 
suggested, would constitute a reduction from what is currently allowed 
since the actual 2012 level of air tour operations was lower than what 
is authorized. It would not be a QT incentive to set a baseline that is 
lower than what air tour operators would be allowed to do under the 
current allocation system. In addition, the agencies chose 2012 as the 
year to model baseline noise. MAP-21 provided renewed direction for QT 
incentives in July 2012 and directed the agencies to provide such 
incentives not later than 60 days after the date of enactment of MAP-
21. While the agencies could not meet the 60-day time frame, it was 
clear that the Congress gave meaning to 2012 with respect to QT 
incentives. An additional consideration by the agencies was the 
availability and currency of air tour fleet and operational data in 
2012, as opposed to looking back to previous years. The alternative of 
selecting either the year 2000 or 2005, as the air tour interests 
suggested, was considered by the agencies, but was not adopted because 
of concerns about re-creating earlier data for modeling input to obtain 
a noise baseline and whether the selection of a past year would 
adequately ensure no increase in noise and no diminishment of the 
achievement of substantial restoration of natural quiet. This latter 
consideration was involved in deciding not to model the noise baseline 
with an all non-QT fleet, which would not reflect the noise environment 
in the Dragon and Zuni Point corridors in 2012. The agencies are also 
cognizant that an incentive must be based on a stable baseline that can 
be relied on by air tour operators as they make QT conversion 
decisions; therefore, the 2012 noise baseline will continue to be used 
for this seasonal relief incentive in future years. With respect to 
using a baseline of substantial restoration of natural quiet, this is a 
separate applicable standard in NPATMA; not a substitute for the no 
cumulative noise increase requirement. Both requirements must be met. 
To ensure that this incentive will not diminish the achievement of 
substantial restoration of natural quiet by exposing new areas of the 
park to air tour noise, all commercial air tour aircraft, including QT, 
must adhere to the existing route structure in the park.
    Comment: The air tour interests suggested that any noise increase 
should be substantial or perceptible in order to justify discontinuing 
the incentive. Commenters representing recreational and environmental 
interests called for transparency and accountability, continued 
modeling and/or monitoring to ensure noise does not increase, and 
suggested that noise data should be made public.
    FAA and NPS Response: The FAA and the NPS are responsible and 
accountable for ensuring that this QT incentive does not increase noise 
at the park or diminish the achievement of substantial restoration of 
natural quiet. The LEQ12 58.1 dB baseline is a fixed 
baseline against which noise increases will be judged. Noise above the 
baseline level will be considered to be an increase, regardless of 
whether it is considered to be either ``substantial'' or 
``perceptible''. The agencies will monitor the air tour operators' use 
of QT for air tours as required to be reported in the operators' 
quarterly reports submitted to the FAA, and will annually model noise 
as described in this notice. Annual noise results will be publicly 
available. In addition, the NPS will use periodic on site monitoring 
consistent with industry standards. The NPS routinely uses monitoring 
to supplement modeling results. Monitoring data would enable the NPS to 
check the number of flights flown on each route segment, providing 
cross-validation for the numbers reported by air tour operators. 
Monitoring data also would provide the single event level (SEL) and 
maximum sound level (Lmax) for each flight, enabling the NPS to confirm 
the benefits of QT aircraft.
    Comment: Some commenters noted that ambient noise levels at the 
Grand Canyon are very low and even QT aircraft can be heard. Commenters 
representing recreational and environmental interests expressed concern 
that overall noise will increase even if QT operations result in a 
reduction in noise per flight and that park visitors will be in worse 
position if the result is more constant noise from more frequent 
flights.
    FAA and NPS Response: The overall noise cannot increase under the 
statutory mandate that provides for the QT incentive to be allowed 
subject to the cumulative impact not increasing noise at the park. The 
LEQ12 metric used to evaluate cumulative impact takes into 
account aircraft noise levels, the number of aircraft operations, and 
the duration of noise. In addition, the incentive cannot, by statute, 
diminish the achievement of substantial restoration of natural quiet at 
the park.
    Comment: Commenters representing recreational and environmental 
interests expressed concern that noise would increase in backcountry or 
elsewhere in the Grand Canyon; that noise would increase in off-season 
when backpacking and hiking is most comfortable and visitors enjoy a 
respite from noise; or that the incentive would result in increased 
flights of loud aircraft in summer.
    FAA and NPS Response: There are statutory protections to preclude 
an overall, i.e., cumulative, increase in noise and to prevent 
diminishing the achievement of substantial restoration of

[[Page 22611]]

natural quiet, as described in this notice and in the response to the 
previous comment. QT aircraft must adhere to the current route 
structure defined for air tour operations; no new areas of the Grand 
Canyon will be opened to air tours under this incentive. The agencies 
do not anticipate a significant increase in the number of air tours 
operated in the winter months when tour demand is low. The incentive 
should increase the proportion of QT aircraft used for air tours in the 
Dragon and Zuni Point corridors and decrease the number of louder non-
QT aircraft. Air tour operators that convert or have converted to QT 
for the seasonal relief are anticipated to continue to operate those 
quieter fleets during the summer season. Seasonal relief allows air 
tour operators to save allocations that would have been used in the 
first quarter of the year and to use them during times of year when air 
tour demand is higher; therefore, there may be increases in the number 
of air tour flights at other times of year above the number that has 
been allowed under the allocation system. If an increase in the number 
of flights rises to the level that results in a cumulative increase in 
noise, the seasonal relief incentive will be modified to reduce noise 
or will be discontinued.
    Comment: Commenters suggest agencies mandate one ``quiet day'' per 
month.
    FAA and NPS Response: This suggestion would presumably involve a 
prohibition on air tours for one day each month, which is outside the 
scope of approved measures currently in place at the park and is not a 
QT incentive.
    Comment: One commenter called for assurance that incentives will 
not degrade substantial restoration of natural quiet.
    FAA and NPS Response: The agencies will ensure that this incentive 
does not diminish substantial restoration of natural quiet as required 
by NPATMA.

Impact on air tour operations

    Comment: Commenters representing recreational and environmental 
interests suggest this is an attempt to increase number of operations 
by labeling them as quieter. The air tour interests express concern 
that operators who have already converted to QT may not see a permanent 
increase in their allocations. Commenters representing recreational and 
environmental interests noted that they expected to see flights shift 
from peak to off-peak as part of a QT incentive. One commenter 
expressed the view that the seasonal relief incentive will result in 
vigorous marketing of air tours in January through March.
    FAA and NPS Response: Currently, air tour operators can use 
allocations at any time throughout the year based on the demand for air 
tours and individual business decisions. This incentive does not change 
that situation. The demand for air tours is expected to remain highest 
in the peak season.
    Comment: Commenters representing recreational and environmental 
interests advocated a cap on operations.
    FAA and NPS Response: Rather than imposing a numerical cap, the 
statutory noise conditions effectively provide a limit.
    Comment: Commenters asserted that more frequent flights will 
produce more air emissions.
    FAA and NPS Response: FAA and NPS air quality specialists do not 
expect air tours to significantly affect air quality in national parks.

V. Implementation Steps

    The FAA and the NPS will use the quarterly reports that are 
currently required to be submitted by the operators to determine the 
number of QT flights flown during the first quarter that will not count 
against their annual allocations. The FAA will implement the incentive 
by amending the operations specifications of commercial air tour 
operators holding allocations in the Dragon and Zuni Point corridors to 
allow them to conduct air tours with QT aircraft without using an 
allocation for such tours in the specified seasonal time periods. The 
FAA and the NPS will cooperatively ensure that the statutory conditions 
protecting the park are met.

VI. Environmental Considerations

    This action involving the FAA's amendment of operations 
specifications is categorically excluded from more detailed 
environmental review because it would not have a significant effect on 
the environment. The FAA and the NPS have designed this incentive to 
ensure compliance with the statutory conditions that the cumulative 
impact of QT operating without allocations does not increase noise and 
that the incentive does not diminish the statutory mandate to achieve 
the substantial restoration of natural quiet at the park.

    Issued in Hawthorne, CA, on March 19, 2015.
Glen A. Martin,
Regional Administrator, Western-Pacific Region, Federal Aviation 
Administration.
    Issued in Lakewood, CO, on March 23, 2015.
Sue E. Masica,
Regional Director, Intermountain Region, National Park Service.
[FR Doc. 2015-09380 Filed 4-21-15; 8:45 am]
 BILLING CODE 4910-13-P