Visitor Perception Study
Aircraft Over the Grand Canyon
This report documents a study of the perception of aircraft and the attitude toward them held by backcountry hikers at Grand Canyon National Park, Arizona. A total of 1,769 usable questionnaires were collected, using both mail and field survey methods. The study was initiated by the National Park Service in response to Public Law 93-620, the Grand Canyon Enlargement Act. Some of the applicable regulations are discussed and prior research on the issue is chronicled.
In all, five separate surveys were conducted. Three were taken in the field; two surveying inner canyon hikers and one capturing a small sample of river runners. The two remaining surveys were conducted through the mail, one covering all individuals who secured a backcountry use permit during April, May, or the first half of June 1983 and the other covering the time period from December l983 to February 1984. While the first covers the peak backcountry use season, the latter was used to contrast the viewpoints of those who hiked in the off-season. Since most of the data was collected in the spring 1983 mail survey and because responses cover all major backcountry trails, these results are analyzed in detail, although results from the other surveys are contrasted throughout the report.
Results from the spring mail survey reveal that, overall, almost one third of the survey participants reported being dissatisfied with the number of aircraft they heard flying over the canyon (Figure 1). Just over 15 percent indicated that they were satisfied, while another 3 percent responded by indicating that they had not heard any aircraft. Participants who hiked the Bass Trail seemed particularly disturbed; 55 percent reported feeling dissatisfied.
FIGURE 1
| Satisfaction with # of Aircraft Heard | Number | Percent |
| Did Not Occur | 31 | 3.1% |
| Dissatisfied | 323 | 32.1% |
| Slightly Dissatisfied | 268 | 26.6% |
| Neutral | 160 | 15.9% |
| Slightly Satisfied | 70 | 7.0% |
| Satisfied | 154 | 15.3% |
When asked how satisfied they were with the number of aircraft they saw, 27 percent responded “DISSATISFIED” and 18 percent marked the response “SATISFIED” (Figure 2). Again, hikers on the Bass trail seemed more impacted with half reporting feelings of dissatisfaction.
FIGURE 2
| Satisfaction with # of Aircraft Seen | Number | Percent |
| Did Not Occur | 31 | 3.1% |
| Dissatisfied | 272 | 27.0% |
| Slightly Dissatisfied | 261 | 25.9% |
| Neutral | 210 | 20.9% |
| Slightly Satisfied | 54 | 5.4% |
| Satisfied | 179 | 17.8% |
Commercial jets seem to have relatively little effect on the hiking experience, although some photographers have commented on the presence of contrails. In all, 56 percent of the participants indicated commercial jets had a neutral effect on the hiking experience (Figure 3). On a scale of one to seven, with one being a “BETTER EXPERIENCE” and seven being a “WORSE EXPERIENCE”, 23 percent responded with five, another 8 percent answered with six, and 7 percent responded with a seven.
FIGURE 3
| Effect of Commercial Jets | Scale | Number | Percent |
| Better Experience | 1 | 12 | 1.2% |
| 2 | 16 | 1.6% | |
| 3 | 16 | 1.6% | |
| No Effect | 4 | 563 | 56.5% |
| 5 | 233 | 23.4% | |
| 6 | 83 | 8.3% | |
| Worse Experience | 7 | 73 | 7.3% |
Rated on the same scale, helicopters appeared much more intrusive; almost one third of the survey participants felt that they created a worse hiking experience (Figure 4). Another 21 percent responded with six, 17 percent with five, and 24 percent recorded a neutral response of four.
FIGURE 4
| Effect of Helicopters | Scale | Number | Percent |
| Better Experience | 1 | 9 | .9% |
| 2 | 17 | 1.7% | |
| 3 | 28 | 2.8% | |
| Neutral | 4 | 236 | 24.0% |
| 5 | 167 | 17.0% | |
| 6 | 206 | 21.0% | |
| Worse Experience | 7 | 320 | 32.6% |
Small propeller driven craft were also rated in the same manner (Figure 5). Approximately 24 percent of the people surveyed responded to each of the response classes four through seven.
FIGURE 5
| Effect of Fixed Wing Propeller Aircraft | Scale | Number | Percent |
| Better Experience | 1 | 7 | .7% |
| 2 | 18 | 1.8% | |
| 3 | 23 | 2.3% | |
| Neutral | 4 | 246 | 24.8% |
| 5 | 227 | 22.9% | |
| 6 | 236 | 23.8% | |
| Worse Experience | 7 | 236 | 23.8% |
When asked how they thought aircraft should be managed, only 22 percent felt they should be managed as present. Almost 86 percent felt that they should be managed to reduce impacts on wildlife, such as the peregrine falcon (Falco peregrinus) although no specific species was mentioned in the questionnaire. Over 69 percent thought sectors of the park should be closed to overflights and also that aircraft should be required to maintain higher altitudes. While 60 percent felt that aircraft should be limited by a curfew of some type, only 29 percent believed aircraft should be eliminated from Grand Canyon’s airspace. Results for the management alternative items are shown in Figure 6.
FIGURE 6
| Management Alternatives | Yes | No |
|---|---|---|
| Should aircraft be managed as present? | 212 | 735 |
| Percent | 22.4% | 77.6% |
| Should aircraft be managed at higher altitudes? | 651 | 294 |
| Percent | 68.9% | 31.1% |
| Should aircraft be managed by closing sections? | 652 | 290 |
| Percent | 69.2% | 30.8% |
| Should aircraft be limited to certain times? | 564 | 370 |
| Percent | 60.4% | 39.6% |
| Should aircraft be managed to reduce wildlife interference? | 793 | 130 |
| Percent | 85.9% | 14.1% |
| Should aircraft flights be eliminated? | 270 | 664 |
| Percent | 28.9% | 71.1% |
Survey participants were also asked what uses of aircraft they felt were justified in flying over Grand Canyon. An overwhelming majority supported the continued use of aircraft for emergency medical evacuation. Almost 80 percent were in favor of continued flights for administration and management purposes and 78 percent favored flights for backcountry maintenance purposes. Three fourths of the respondents felt research overflights were justified. While almost 73 percent felt scenic tours over Grand Canyon should be offered to the handicapped, only 44 percent thought scenic tours in general were a justifiable use of Grand Canyon’s airspace. Figure 7 shows the results for the six items.
Figure 7
| Purposes for Aircraft Use | Yes | No |
|---|---|---|
| Evacuating people with medical emergencies? | 999 | 8 |
| Percent | 99.2% | 0.8% |
| Flying over the canyon for administrative or management purposes? | 784 | 199 |
| Percent | 79.8% | 20.2% |
| Upkeep of trails, removing sewage, or other backcountry maintenance? | 772 | 218 |
| Percent | 78.0% | 22.0% |
| Conducting scientific research? | 732 | 243 |
| Percent | 75.1% | 24.9% |
| Transporting the handicapped or physically impaired over the canyon? | 702 | 265 |
| Percent | 72.6% | 27.4% |
| Conducting scenic tours of Grand Canyon? | 415 | 532 |
| Percent | 43.8% | 56.2% |
When asked whether they personally were willing to give up the opportunity to see Grand Canyon from the air, 84 percent of the survey participants indicated that they would. Only 62 percent were willing to deny this same opportunity to others (Figure 8).
Figure 8
| Options | Yes | No |
|---|---|---|
| Give up the opportunity to see Grand Canyon by air? | 830 | 156 |
| Percent | 84.2% | 15.8% |
| Deny others the opportunity to see Grand Canyon by air? | 590 | 366 |
| Percent | 61.7% | 38.3% |
In the body of the report, respondents were divided into various groups and the results were compared with the overall response. The first examination was by use area giving an indication of how the effect of aircraft differed throughout the park. In general, Bass Canyon, Thunder Falls/Deer Creek, and Tanner Trail show up as being somewhat more negatively impacted, although this is probably as much a result of the type of individuals who hike these more remote sections of the park as a reflection of the density of aerial overflights. Respondents were also subdivided as a function of whether they had taken a flight over the canyon, and also whether they had flown with a scenic tour. As could be anticipated, those who had flown in a scenic tour were generally more favorably inclined toward such uses of aircraft.
Hikers were also classified depending on the number of previous hiking trips into Grand Canyon. Though not evident in the responses for all items, the greater the number of previous hiking trips, the more respondents felt aircraft represented an intrusion into their backcountry experience.
Appendix 1 discusses the effect of urban, suburban, or rural residence on the responses given. As a generalization, rural residents seemed to be the most sensitive to aircraft intrusions.
Results for Arizona state residents are broken out in Appendix 2 as are the responses for local area residents, which were identified by the Zip-code prefix of 860. While local residents indicated a somewhat higher level of concern about park uses of aircraft they were generally less supportive of aircraft restrictions and the majority, 53 percent, opposed eliminating scenic tours.
Appendix 3 contains the comments received from a random sample of questionnaires from the spring mail survey. Many respondents put considerable thought into the issue, as is reflected in many of the written responses.
A brief comment on the significance of the results; if two populations could be contrasted, one which had experienced aircraft on the hike and another which had not been subjected to overflights, the groups could be compared and a determination made as to whether or not statistically significant differences were produced. Given the situation in the canyon, the latter group did not exist. As a result, only the percentage of the population with each given viewpoint could be reported. Since the Grand Canyon Enlargement act requires the Secretary of the Interior to have “reason to believe” that aircraft or helicopter activity is likely to cause “a significant adverse effect on the natural quiet and experience of the park”, the term significance acquires a different, non-statistical meaning. At what point the results documented here become “significant” is a matter to be determined in the political, social, and economic realm.
Mi Mayan Hamaca 