CHAPTER 7

Section 1(c) of Public Law 100-91 mandates that the National Park Service assess the safety of on-ground visitors relative to aircraft overflights :

"The research at each such [park] unit shall provide information and an evaluation regarding each of the following:

(1) the impacts of aircraft noise on the safety of the park system users, including hikers, rock-climbers, and boaters....”

The NPS addressed this question through the Park Manager Survey, the system-wide Visitor Survey, and by contacting numerous outdoor recreation organizations who might have knowledge of the issue. Results are discussed in the following sections.

7.1 Concerns of Park Management

Visitor safety is a major concern of NPS managers and park staff. In order to obtain the broadest possible perspective about these concerns as they may be related to aircraft overflights, the Park Manager Survey (HBRS, Inc., 1993) included questions about aircraft and visitor safety. Questionnaires were sent to 98 park managers whose units had previously been identified as having aircraft overflight concerns. Of the 98 parks, 91 provided detailed responses. The responses provided by these managers give insight into the nature and extent of the perceived problem in the National Park System. Although statistical inference cannot be made to the entire System, the NPS is confident that this information is representative of the nature and extent of agency concerns and certainly reflects those situations where aircraft overflights have generated a level of management concern.

Managers were asked their opinion on how much of a problem aircraft overflights posed to visitor and staff safety at their park. Figure 7.1 reports the results. Of the 91 parks responding, 62 percent of the managers either said that overflights were not a safety problem, or that they were only a slight problem. Another 20 percent indicated overflights were a moderate safety problem. The remaining 18 percent, however, responded that overflights were a serious or very serious safety problem. Table 7.1 identifies the parks where serious and very serious problems are perceived.

In the same survey, managers were also asked to provide some detail as to the nature of their safety concerns. Table 7.2 provides an alphabetical listing of the parks from Table 7.1, the nature of management's safety concerns, and the type of aircraft typically involved. This table shows a diverse range of safety issues. The NPS recommends that these situations be investigated by the FAA.

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Table 7.1 Parks Where Safety is Perceived as a Serious, or Very Serious Problem

VERY SERIOUS PROBLEM

Chaco Culture National Historic Park

City of Rocks National Reserve

Fort Vancouver National Historic Site

Gateway National Recreation Area

Glen Canyon National Recreation Area

Sequoia & Kings Canyon National Parks

Pipe Spring National Monument

Prince William Forest Park

Statue of Liberty National Monument

SERIOUS PROBLEM

Big Bend National Park

Bryce Canyon National Park

Channel Islands National Park

Fire Island National Seashore

Gulf Islands National Seashore

John Day Fossil Beds National Monument

Perry's Victory & International Peace Memorial

The NPS needs to further evaluate situations where moderate problems are perceived to exist. Moderate problem priorities would include Hawaii Volcanoes National Park where aircraft are believed to be flying dangerously low over visitors and molten lava and where visitors have been struck by gravel, wind, and rotor wash and the Great Smoky Mountains National Park where helicopters have been reported to have spooked trail horses and the superintendent is concerned about a possible mid-air collision.

The FAA is already looking at the safety situation in Hawaii where from 1991-1993 there have been 46 sightseeing aircraft and rotorcraft accidents resulting in 46 injuries and 37 fatalities. FAA inspectors have accompanied park rangers and resource managers to document instances of inappropriate and dangerous flying over Hawaii Volcanoes National Park, including flying through volcanic fumes and low over molten lava.

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Table 7.2 Visitor Safety Concerns Reported to Park Management During FY 1992

Managers were also asked to indicate the degree to which they perceive visitors and park staff are concerned about their own safety as a result of aircraft overflights over their park. The results are shown in Figure 7.2. In general, the result shows that managers believe visitor and staff concerns to be about the same. About 74 percent of the managers felt that staff and visitors were not concerned or were only slightly concerned about personal safety. Approximately 10 percent felt these two groups were moderately concerned; only 6 percent of the managers felt that visitors and staff were very or extremely concerned about safety in their park.

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The difference in perception between managers and visitors is, in part, a function of the managers’ responsibility for visitor safety, but it also may reflect the number of crashes that have occurred in NPS areas.¹ Through the survey, managers provided a listing of aircraft incidents (crashes) that occurred in their parks during the past 5 years. A summary of the information provided is presented in Figure 7.3. The figure shows the number of incidents, in terms of type of activity, reported by the managers. This figure shows blocks of varying heights which indicate the total number of incidents. Propeller-driven general aviation airplanes, propeller-driven sightseeing airplanes, and military jets were the types of aircraft most frequently involved.²

Conclusion 7.1

Relatively few park managers perceive safety concerns to park visitors and staff from aircraft overflying their parks. Attention needs to be given to those few parks where serious or very serious safety issues are perceived.

7.2 Concerns of Park Visitors

Similar questions were included in the survey of park visitors that was conducted in 1992 (McDonald et al. 1994) at 39 parks representing the National Park System (excluding Alaska). In the mail survey that was sent to selected survey participants were questions relating to visitors’ perceptions on safety from aircraft flying overhead.

In one series of questions, visitors were asked how hearing or seeing aircraft affected their visit to the park. A specific question asked how concerned they were about their safety from aircraft flying overhead. The responses are shown in Figure 7.4. Visitors indicated their degree of concern by selecting one of the five categories shown at the bottom of the graph. The figure shows that 99 percent of the respondents were either not at all or only slightly concerned. Just 1 percent of the visitors reported being moderately concerned about their safety, and none reported being very or extremely concerned. This is a good indicator that any safety problems are occurring in relatively few places and very infrequently at that. The greater degree of concern among managers as compared to visitors is also undoubtedly related to a long term exposure to overflight incidents and their overall responsibility for visitor safety. Short-term visitors simply don't have that exposure or responsibility.

In a counter-question, visitors were also asked if aircraft overflights made them feel safer in case they needed rescue. Figure 7.5 shows the responses. For this question, 90 percent of the respondents said that aircraft proximity did not increase their feeling of safety, or if so only slightly. However, 10 percent of the visitors did report an increased feeling of safety, to a "moderate", "very", or "extreme" degree.

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1. It is the understanding of the NPS that all these incidents were reported to the FAA and investigated by the National Transportation Safety Board (NTSB).

2 .Miscellaneous incidents include those involving ultra-light aircraft, a glider, a hot air balloon, and a blimp whose tether line struck the Statue of Liberty.

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Conclusion 7.2

Virtually no visitors perceive concern for their safety from aircraft overflights, an indicator suggesting that any safety problems are occurring in relatively few places and infrequently.

7.3 Outdoor Recreation Community Concerns

In 1993 the NPS wrote to a broad array of outdoor recreation groups to inquire whether they could identify any on-the-ground safety issues related to aircraft overflights of the National Park System during the last 10 years. Groups contacted included, among others, the following organizations:

 

American Alpine Club	The Wilderness Society
Colorado Mountain Club	Sierra Club
American Mountain Guides Association	National Outdoor Leadership School
Colorado Outward Bound	Backcountry Horseman of America

A limited number of written and verbal responses were received. Most of the comments dealt with the startle effect of aircraft on themselves, clients, or friends. No serious or lasting injuries were reported. Several comments dealt with the inherent incompatibility of horses and helicopters and offered examples of this incompatibility. The writers of the letters also used the opportunity to voice concern about wildlife harassment by aircraft and the impact of aircraft on visitors’ experience in remote areas of parks.

Conclusion 7.3

Although some outdoor recreation organizations indicated a low level of concern on safety related to aircraft overflights, this level again suggests local or infrequent problems as well as concerns for other types of impacts. Ensuring a segregation between helicopters and horse traffic in some situations may be desirable.

7.4 Temporary Flight Restriction (TFR) Problems 

Low-level airspace over public lands can sometimes be very busy. This airspace can be attractive to air tour operators as well as to general aviation. It is at these altitudes that much military tactical training occurs. They are the same altitudes where the NPS and other land management agencies conduct wildlife surveys, animal capture and control flights, law enforcement flights and aerial firefighting. The potential for conflict is significant, especially in bad fire years. In 1992, 59 airspace conflicts involving Department of the Interior aircraft were reported. Of these, 39 were near mid-air collisions---11 with military aircraft and 28 with civilian aircraft. Characteristically, conflicts with military aircraft generally occur in the Western United States where there is a concentration of military training routes and unlit operations areas. Conflicts with civilian aircraft more often occur in the higher density air traffic areas along the Eastern seaboard.

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The FAA, Department of Defense, and Department of Interior have already begun to work on this issue. Apparently the key to resolving this safety problem is dissemination of the Temporary Flight Restriction (TFR) information to pilots who are already in the air when the notice is issued. TFR'S are issued through the FAA (Federal Aviation Regulation 91.37A) and distributed to pilots using FAA's "Notice to Airmen" (NOTAM) system. Great numbers of these NOTAMS are issued every day dealing with a myriad of topics which make it difficult for pilots to identify which ones will affect their routes. This is especially true of unlit pilots who may be flying across the country.

Communication is the crux of the issue. Direct coordination, especially with the military would help, but it is difficult for the NPS and other land management agencies to know with whom they should talk. A simple, national level system is needed to rapidly disseminate airspace information to all pilots. Progress has been made:

• The Bureau of Land Management and the Forest Service are developing a "Computer-aided Aviation Hazard Identification System" (CAHIS) to assist natural resource agencies in planning air operations in areas which have a high volume of military activity.
   
• ( The Department of Interior has petitioned the FAA to create a separate and distinct transponder code to be used by natural resource aircraft for radar identification. This transponder code would be available in the near future.
   
• The Department of Defense is exploring communication links for scheduling military training routes and special use airspace.

   Conclusion 7.4

  As airspace over public lands becomes more congested, the potential for conflicts is increasing. Although progress is being made in resolving these airspace issues, the 39 near-misses in 1992 indicate the need for improved communication links at an operational level between FAA, Department of Defense agencies, the NPS and other land management agencies.

7.5 Summary

There is no evidence of any serious or wide spread safety problem for on-ground visitors or park employees tied to aircraft overflight. There are problems in a limited number of areas that should to be addressed. Problems in a number of other areas should be evaluated further. Only a few managers and virtually no visitors perceived any safety problem related to aircraft overflight. Some elements in the outdoor recreation community expressed concern, but the incidents triggering these concerns are probably isolated and could be dealt with in the context of a better reporting system. Procedures and communications are currently lacking, and this is a problem that the involved agencies can address if they are willing to work together to prevent problems. The potential seriousness of the situation should not, however, be ignored. On the Pacific Crest Trail in 1988, an Oregon couple were thrown from their horses as a result of a low level flight; the man had a fractured skull and his wife broke her back, collarbone, and a rib.

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The NPS and other land management agencies should work with the DOD and FAA to develop procedures for use in dealing with the airspace / park use issues that occur in complex airspace (i.e. special use airspace, unlit operations areas and unlit training routes) especially during fire fighting or other major incidents. important steps have been taken, but communication at an operational level should be significantly improved.

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