Runway-Area Topographic Considerations In Airport Licensing

By

Mr. Brian Hatcher, Mr. Todd Sullivan, Mr. Jeff Tedder, Mr. Jon Williams, and Dr. Charles D. Haynes

Department of Civil and Environmental Engineering The University of Alabama

Tuscaloosa, Alabama

Prepared by

UTCA University Transportation Center for Alabama

The University of Alabama, The University of Alabama at Birmingham, and The University of Alabama in Huntsville

UTCA Report Number 03108

December 31, 2003

Technical Report Documentation Page

1. Report No FHWA/CA/OR-

2. Government Accession No. 3. Recipient Catalog No.

5. Report Date December 31, 2003

4. Title and Subtitle Runway-area Topographic Considerations In Airport Licensing 6. Performing Organization Code

7. Authors Mr. Brian Hatcher, Mr. Todd Sullivan, Mr. Jeff Tedder, and Dr. Charles Haynes

8. Performing Organization Report No. UTCA Final Report 03108

10. Work Unit No.

9. Performing Organization Name and Address The University of Alabama Department of Civil and Environmental Engineering P.O Box 870205 Tuscaloosa, AL 35487-0205

11. Contract or Grant No. DTSR002324 13. Type of Report and Period Covered Final Report: January 1 – December 31, 2003

12. Sponsoring Agency Name and Address University Transportation Center for Alabama The University of Alabama Department of Civil and Environmental Engineering P.O Box 870205 Tuscaloosa, AL 35487-0205

14. Sponsoring Agency Code

15. Supplementary Notes 16. Abstract Alabama’s general use airports were studied by traditional surveying and global positioning satellite techniques to determine if natural or manmade topographic hazards existed in their runway protection zones (RPZ). The severity of obstructions in the RPZ was rated on a scale of 1-5, with the severity increasing with number. Many of the airports surveyed have significant obstructions in their RPZ and are a hazard to approaching and departing aircraft. The results of this study point to the use of a RPZ obstruction rating as part of the Alabama Department of Transportation (ALDOT) airport design algorithm. The data generated during this project was compiled as a Technical Appendix, published in two companion reports for this project (UTCA Reports 03108-A and 03108-B). Photographs were taken of runway-end conditions during the project; these were provided to the ALDOT Aviation Bureau. 17. Key Words Runway, approach, departure, airport design, topography, Protection zones

18. Distribution Statement

19. Security Class (of this report)

N/A

20. Security Class (of this page)

N/A

21. No of Pages

22. Price

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Contents Topic Page Contents …………………………………………………………………………… iii List of Tables ……………………………………………………………………… iv List of Figures …………………………………………………………………... v Executive Summary ……………………………………………………………….. vi 1.0 Introduction ……………………………………………………………………. 1 1.1 Study Purpose ……………………………………………………………... 1 1.2 Project Approach ………………………………………………………….. 2 2.0 General Aviation Overview 2.1 General Aviation Airports and Their Community …………………………. 3 2.2 Safety Impacts ……………………………………………………………… 3 3.0 Methodology ……………………………………………………………………. 5 3.1 Aerial Photographs and Topographic Pictures …………………………. …. 5 3.2 Field Surveying ……………………………………………………….......... 5 3.2.1 Stadia Survey ………………………………………………………… 5 3.2.2 GPS Verified Survey ………………………………………………… 6 3.2.3 Sight Verified Survey ………………………………………..... ……. 6 4.0 Project Results …………………………………………………………………. 7 5.0 Project Conclusions and Recommendations …………………………………… 13 6.0 References ……………………………………………………………………... 14 7.0 Technical Appendix

Appendix 1: Airport Diagrams and Surveys ...…………………………….. 15 Appendix 2: Runway Protection Zone Obstruction Photographs ………..... 15

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List of Tables

2-1 Obstructions Struck in Overrun Accidents……………………………………. 4

4-1 Airport Rankings………………………………………………………………. 8

List of Figures 2.1 Location of Runway Environment Accidents………………………………… 4

3.1 Safe Runway-End Topography, Marion County (Hamilton) Runway 18….... 7

3.2 Unsafe Runway-End Topography, George Downer (Aliceville) Runway 24… 7

4.1 Runway Topographic Data Form……………………………………………… 12

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Executive Summary A study was performed to assess and rank the runway-area topography of Alabama’s general use airports. Traditional surveying and global positioning satellite techniques were used to identify topographic features that pose hazards to arriving and departing aircraft. Such hazards included, but were not restricted to: ditches, uneven terrain, adverse slopes, standing water, tree stumps, and manmade obstructions. The obstructions described above were ranked on a scale of 1-5, with larger numbers corresponding to more severe situations. Many airports were deemed to have sufficient obstructions to pose hazards to aircraft that might undershoot or overshoot the runway. Because of the number of topographic obstructions found in this study, it is recommended that runway-area topography be considered in the licensing algorithm for Alabama’s general use airports. The inspection data generated during this project was compiled as a Technical Appendix, which was published in two companion reports for this project (UTCA Reports 03108-A and 03108-B). Photographs taken of runway-end conditions were provided to the ALDOT Aviation Bureau.

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Section 1 1.0 Introduction Over the last century, aviation has been a catalyst for economic growth and has enriched the quality of life for all Americans. It has connected every sector of business and every region of the world with its speed and convenience. As aviation grows, safety becomes the primary concern of communities and persons utilizing aviation facilities and opportunities. These concerns have caused the formation of agencies at state and federal levels focusing on safety, capacity, and efficiency. Civil aviation includes all commercial airline operations and general aviation (GA). GA, the focus of this project, includes all flights which are not scheduled or chartered. GA supports over 1.3 million high-skill, high-wage jobs comprising over one percent of the U.S. gross domestic product. The number of people using small aircraft for personal, business, and recreational purposes in the United States has increased to over 145 million passengers a year causing a corresponding increase in the demand for adequate GA airports. GA passengers currently have access to over 5,400 public use (or general use) airports located all over America. These public use airports are the responsibility of state governments that determine and apply safety criteria to ensure that airports in their responsible care operate according to these criteria (www.gaservingamerica. 2003). 1.1 Study Purpose The majority of aircraft accidents occur in the runway environment through loss of directional control because of mechanical failure, reverse thrust failure or misapplication, braking systems malfunction, and pilot error. When this happens, it sometimes results in excursions off the paved runway surface onto the runway end areas or locations adjacent to the runway. Obstructions such as large rocks, stumps, earth mounds, depressions, and manmade obstacles can turn what the FAA refers to as an “incident” into a full-blown accident. Federal guidelines for airport design specify certain grade limits at the end of runway centerlines as well as perpendicular to the centerline. These runway–end areas are termed runway protection zones (RPZ). State guidelines for new general use airport licensing follow federal guidelines (Horonjeff, et al. 1994), but older airports were often not designed for, or brought up to, these standards. Under current Alabama airport licensing conditions, inspection emphasis is given to obstacle clearance for runway approaches but not necessarily to the runway-end environment. This allows airports with unsafe terrain in the runway protection zones to obtain licensing while operating with unsafe conditions. Beginning January 1, 2005, Alabama inspection criteria will require that the land area beneath the approach and departure path for all publicly owned

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runways, nominally 1,000 feet from the runway ends, be owned and/or managed by the airport owner. Currently, this control is encouraged but not enforced. This project inspected 82 Alabama GA airports to determine if unsafe topographic features existed in the runway environment. This generally included all property within 1,000 feet of a runway threshold. The primary objectives for this project were to:

1. Alert pilots of potentially unsafe runway-area obstructions conditions that may not be current in federal guides or consumer-oriented web sites such as AirNav.Com (AirNav.Com. 2003).

2. Rank the severity of these obstructions using a simple scale. 3. Determine if topographic features in the runway environment should be included in general use airport licensing criteria.

1.2 Project Approach The following work tasks were used to accomplish the project objectives:

1. Inventory runway-area topographies for 82 general use airports in Alabama. This hands-on phase created a runway topography survey data sheet for these airports. All hazardous topographical features in the runway-end environment were included in the database.

2. Incorporate topographic data into the Alabama Department of Transportation (ALDOT) Aviation Bureau licensing database.

3. Depending on the severity of the obstructions found in the runway-end environment, determine if these data should be included in the revised weighted airport-licensing procedures for Alabama’s general use airports.

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Section 2

2.0 General Aviation Overview Public and private airports that do not offer regularly-scheduled commercial flight services are classified as general use airports. The condition, facilities, and services of these airports vary significantly. Most have paved runways but in some cases the runway is turf or gravel. Many general aviation airports do not have lighted runways and navigational aids. Even with these shortcomings, however, these airports provide a vital link between businesses and smaller communities. The United States averages approximately one airport for every 700 square miles, most of which fall under the category of general use airports. 2.1 Impacts of General Aviation on a Community General aviation benefits users of transportation services as well as communities’ economy. It improves efficiency and productivity of business by reducing point-to-point travel time. It also provides public health services and supports public safety activities. Perhaps general aviation’s largest role in our society is its ability to increase the competitiveness of local businesses. Companies seeking new office and factory sites usually locate in the vicinity of a general aviation airport. One state recently found that more than 70 percent of new or expanded companies intentionally located within ten miles of a general aviation airport (www.gaservingamerica. 2003). The Small Aircraft Transportation System recently being promoted by NASA points to the increasing importance of general aviation in augmenting the serious shortage of scheduled and charter flights to rural areas (Nickerson, J, et al. 2002). 2.2 Safety Impacts With the increasing number of current and proposed passengers using general aviation, new emphasis has been placed on the safety of all public airports. These airports must be safe for the surrounding community along with the passengers arriving and departing the airport. Since safety conditions vary widely at public airports, knowledge of current airport safety information is a key element for pilots planning a flight to a public airport. International Civil Aviation Organization accident data show that 80 percent of aviation accidents take place within 500 feet of the active runway centerline and 3,000 feet of runway thresholds. Airport accidents are usually divided into three general categories:

• Undershoots: the aircraft contacts the ground or an obstruction prior to reaching the runway.

• Veeroffs: the aircraft loses directional control on the runway • Overrun: the aircraft hydroplanes, skids, or has excess landing speed. Included in this

category are rejected takeoffs where the plane leaves the paved runway surface (Ashford, et. Al. 1992).

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A National Transportation Safety Board survey found that in 41 of 50 accidents, aircraft hit obstructions in overrun areas. The obstructions and occurrences noted during the survey are listed in Table 2-1 and shown in Figure 2-1 (Nickerson, J, et al. 2002). Table 2-1

Accidents in the runway environment

Obstructions Occurrences Lights and Stanchions 10 Embankments and Dikes 7 Fences 6 Trees 4 Boulders 3 Hills and Mounds 3 Navigation Facilities 2 Other Aircraft 2 Automobiles 2 Building 1 Roadway 1

Figure 2-1 Location of runway environment accidents (Ashford, et al. 1992)

According to Federal Aviation Administration (FAA) guidelines for Runway Protection Zones, only lights, stanchions, and navigational aids can be located in the RPZ. When these obstructions are located in the RPZ, they must contain a breakaway support system.

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Section 3

3.0 Methodology This section outlines the procedure used to investigate the runway-end environment of Alabama’s general aviation airports according to the FAA guidelines. Also provided is an overview of the use of aerial photography, topographic maps, and field surveys to compare grading and obstructions to federal guidelines. 3.1 Aerial Photographs and Topographic Maps Aerial photographs and topographic maps were the first to be used in this investigation of runway-area topography. Using aerial photographs from www.topozone.com, possible obstructions and property lines were noted before a field survey was made. However, an aerial photograph was not applicable for every airport, because they were either out of date or had insufficient clarity. Topographic maps from DeLorme TopoQuad 3D® proved to be a very useful tool in locating airports and studying their surrounding topographic environment. Knowledge of an airport’s surrounding topographic features allowed a decision about the type of survey required and provided a basic knowledge of the airport prior to the site visit. All topographic maps used in this project are shown in the Technical Appendix, published as UTCA Reports 03108-A and 03801-B. 3.2 Field Surveying A field survey was conducted at 82 general use airports in Alabama. Each of these airports was examined for obstructions and surface grading problems. A variety of methods were used, including:

(1) Stadia Surveying (2) Global Positioning Survey (GPS) Verified Surveying (3) Sight Verified Surveying

3.2.1 Stadia Surveying The majority of surveys in this project used the stadia surveying method. Stadia is a form of distance measurement that relies on fixed angle intercepts to optically measure the distance along the sight path. Stadia is ideally suited to determine the location of natural features that cannot be precisely defined or located alone. The use of a surveyor’s theodolite allowed a sufficiently precise determination of distances along with reference angles to pinpoint obstructions and topographic changes located in the runway-end environment.

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The first step in the stadia surveying method involved choosing a reference point for the survey. A point located on the runway threshold, whether on its edge or centerline, proved to be an acceptable reference. Measurements were then taken from a reference elevation of zero on the runway surface. Instead of surveying a set interval of distances and offsets, obstructions and topographic changes were chosen and surveyed. From these readings, a diagram was constructed showing obstructions and topographic properties. 3.2.2 GPS Verified Surveying GPS verified surveying was performed using a handheld Garmin GPS unit. This method was used to perform stadia surveying without the use of the theodolite equipment. A reference point on the runway end was located and its elevation found. Using this elevation, other elevations were found with respect to the reference elevation. Since this form could not give exact angles of reference, a method of offset distances was used. First, a distance was found perpendicular to the runway centerline and then a distance parallel to the runway was found to locate an obstruction or elevation change. From these readings, a diagram was constructed showing obstructions and topographic features. 3.2.3 Sight Verified Surveying Sight verified surveying was rarely used in the project. Researchers confined this method of surveying to airports that appeared to have no obstruction problems or those that had non-controlled property located close to the runway threshold. An example of an airport with no apparent problems was the Marion County Airport in Hamilton, Alabama. This airport has a paved overrun and complies with the desired 1000 feet extensions from either end of the runway with no obstructions or grading problems (Figure 3-1). This method was also used at George Downer Airport in Aliceville, Alabama due to a 4-foot high fence and farm equipment parked less than 150 feet from the threshold of Runway 24 (Figure 3-2).

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Figure 3-1 Safe runway-end topography, Marion County (Hamilton) Runway 18

Figure 3-2 Objects in runway-end topography, George Downer (Aliceville) Runway 24

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Section 4

4.0 Project Results Upon completion of field surveying, a ranking system was formulated based on an arbitrary scale of one to five. This system ranks each runway-end environment based on grading problems, obstructions, and property limitations. The ranking system was designed using the criteria in Table 4-1:

Table 4-1 Ranking scale and criteria Ranking Number Criteria

1 No problems to very miniscule problems 2 Small topographic grading problems and/or small obstructions that are easily

correctable 3 Small topographic grading problems and/or small obstructions. Property line

ends prior to 1,000’ beyond threshold. 4 Large topographic grading problems and/or large obstructions. Property line

ends prior to 1,000’ beyond threshold. 5 Large topographic grading problems and/or large obstructions that would

cause major aircraft damage in the off-runway areas.

A list of surveyed general use airports and their respective rankings are provided in Table 4-2. Along with these rankings, a generic airport survey form (Figure 4-1) was completed for each airport. These surveys were designed to gather information in a simple format that can inform pilots of obstructions or hazards, and are suitable for placing on the Alabama Department of Transportation Aeronautics Bureau website. A diagram was drawn for each general use airport displaying the location of obstructions, and in some cases a topographic map was also included. Appendix A of this report contains sample materials from an airport visit conducted during this project (topographic may, diagram, and completed rating forms). Due to the volume of this information and collected data, the results from the survey form and diagrams were placed in a Technical Appendix. The reader is encouraged to review this Appendix to obtain the full benefits of the project (UTCA Reports 03108-A and 03108-B).

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Table 4-2 Runway ratings (part 1 of 3)

City RWY No. Rating City

RWY No. Rating

Abbeville 35 5 Chatom 30 4 17 5 12 4

Addison Grass Clanton 26 4 Alabaster No access 8 2

Addison Grass Clayton 27 3 Albertville 5 3 9 4

23 1 Courtland 17 1 Alexander City 36 1 35 1 18 3 13 1 Aliceville 4 31 1

5 Cullman 2 3 Andalusia/Opp 11 20 3

29 ILS

Dauphin Island 12 4 Anniston 30 4

ILS

Decatur 18 1 Ardmore 3 36 3

5 Demopolis 22 3 Ashland/Lineville 9 3 4 4

27 3 Double Springs 3 5 Atmore 30 4 21 5

12 5 Chatom 30 4 Auburn 10 4 12 4

28 4 Clanton 26 4 36 4 8 2

18 4 Clayton 27 3 Bay Minette 8 4 9 4

26 Closed Elba 19 5 Brewton 18 4 1 5 36 5 Enterprise 23 1 29 4 5 3 6 5 Eufaula 36 4 12 2 18 4 30 1 Eutaw 34 5 Butler 29 3 16 3 11 4 Evergreen 28 3 Camden 18 4 10 3 36 3 Fairhope 19 3 Centre 27 4 1 3 6 3 Fayette 36 2 Centreville 28 3 18 3

10 1 Florala 22 4 4 3

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Tale 4-2 Runway ratings (part 2 of 3)

City RWY No. Rating City RWY

No. Rating

Evergreen 28 3 Jasper 27 3 10 3 9 1

Fairhope 19 3 Lanett 8 4 1 3 26 5 Fayette 36 2 Luverne 22 2 18 3 9 4

Florala 22 4 Marion (Vaiden) 16 1 4 3 34 1

Foley 18 3 Mobile (Downtown) ILS

36 3

Fort Deposit N/A N/A Mobile (Skywest) ILS

N/A N/A

Fort Payne 22 4 Monroeville ILS

4 3

Gadsden 6 1 Muscle Shoals ILS

24 4

Geneva 29 4 Oneonta 5 3 11 3 23 3

Greensboro 36 3 Ozark 12 1 18 3 30 5

Greenville 14 5 Jasper 27 3 32 4 9 1 Grove Hill 13 4 Lanett 8 4 31 3 26 5

Gulf Shores No access Luverne 22 2 Guntersville 3 1 9 4 21 4 Marion (Vaiden) 16 1 Haleyville 18 3 34 1

36 3 Mobile (Downtown) ILS

Hamilton 18 1 Mobile (Skywest) ILS

36 1 Pell City N/A N/A Hartselle 36 3 N/A N/A 18 4 Pine Hill 9 3 Hazel Green 7 3 27 3

25 4 Prattville 9 3

Headland 27 4 27 1

9 3 Reform 1 2

Huntsville (Moontown) Grass 19 1

Pell City N/A N/A

Huntsville (Madison Co.) 18 2 N/A N/A

36 2 Pine Hill 9 3

Jackson 36 4 27 3

18 1

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Table 4-2 (part 3 of 3)

City RWY No. Rating

Pell City N/A N/A N/A N/A

Pine Hill 9 3 27 3

Prattville 9 3 27 1 Reform 1 2 19 1

Roanoke 29 4 11 3

Russellville 1 N/A 19 N/A

Saint Elmo 6 1 24 1 Scottsboro 3 5 21 2 Selma 15 1 33 1

Stevenson 5 1

23 1

Sylacauga 27 N/A

9 3

Talladega ILS

Tallassee 31 5

13 5

Troy ILS

Tuskegee 31 3

13 3

Union Springs 14 N/A

32 N/A Vernon 16 5 34 5 Weaver 26 3 8 3

Wetumpka 27 4

9 4

11

Figure 4.1 Generic airport rating form

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Section 5

5.0 Project Conclusions and Recommendations Although land availability near airports is usually scarce, guidelines for the runway end safety area have been published (Ashford, et al. 1992). These guidelines suggest 3,000 feet beyond the runway end, 1,000 feet in width at the threshold, and 2,000 feet in width at the boundary. This area should be cleared of all obstructions except for navigational facilities. A smooth transitional area should be constructed between the safety areas and the surrounding terrain. Particular attention should be given to streams and drainage ditches, both of which are natural obstructions in the runway end environment. If it is assumed that a runway rating of “3” in this project expresses concern for the runway topographic environment, then Alabama’s general use airport system is in need of improvement. Again, using a rating of “3” as a threshold of concern, over 82 percent of Alabama’s general use airports surveyed in this project had topographic problems or obstructions in the runway-end environment. The magnitude of this problem implies that a runway-end topographic rating should be included in state airport licensing criteria. Airports in Alabama will soon be required to own or control all property up to 1,000 feet beyond a runway threshold. Based on the results of this study, 76.4 percent of state GA airports do not currently meet this requirement. The runway-end area topography acquired in this study can be provided to pilots planning flights to state airports, through the Alabama Department of Transportation Aeronautics Bureau website. These data would allow pilots to be aware of potential hazards in the runway environment during their flight planning activities.

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Section 6

6.0 Bibliography General Aviation Serving America, http://www.gaservingamerica.com, accessed February 2003 Horonjeff, Robert and McKelvey, Francis: Planning and Design of Airports, 4th Edition,

McGraw Hill, 1994 AirNav.Com, http://airnav.com, accessed Feb 2003 Alabama Department of Transportation, Aeronautics Bureau web site,

http://www.dot.state.al.us/bureau/aeronautics, accessed February 2003 Kazda, Antonin, and Caves, Robert: Airport Design and Operation, Pergamon Press, 2000. Ashford, Norman, and Wright, Paul: Airport Engineering, 3rd Edition, Wiley Interscience, 1992. Federal Aviation Administration, Advisory Circular AC 150/5300-13 Nickerson, J, et al: Innovatively Saving the Future of Transportation: Small Aircraft

Transportation System (SATS), Journal of Public Transportation, Vol. 5, No. 3, Center for Urban Transportation Research, 2002.

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Section 7

7.0 Technical Appendix As previously mentioned in the body of this report, the information and data collected were so voluminous that they were placed in as a separate technical appendix to accompany this report. The technical appendix has been published UTCA Reports 03108-A and 03108-B. For each GA airport surveyed, the Technical Appendix contains the following:

• Runway Area Obstruction Survey Form • TopoQuad 3D® Topographic Maps • Topographic Maps of Surveyed Areas Showing Obstructions • Line drawings of obstructions in the airport runway environment

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Appendix A

Sample Materials from Field Survey (Abbeville Municipal Airport)

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Figure A-1 Sample topographic map

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Figure A-2 Sample site drawing

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Figure A-3 Sample runway end rating form

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Figure A-4 Sample runway end rating form

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