Airfield Apron and Ramp Surface Markings (2023)

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

35   Case Examples The results of the industry survey were leveraged to identify multiple case examples to con- duct to further identify and document unique apron/ramp marking practices used at airports across the United States. Airports of various sizes and in different locations were asked to partici- pate. The case examples were separated into the same marking categories established for the industry survey. However, an additional case example was added for markings on Customs and Border Protection (CBP) aprons. The following list shows the case example categories and the airport(s) participating in each case example: • Terminal Gate Area Markings – Case Example #1—Cincinnati/Northern Kentucky International Airport (CVG) – Case Example #2—Hollywood Burbank Airport (BUR) • Taxilane/Apron Markings – Case Example #3—Seattle-Tacoma International Airport (SEA) – Case Example #4—Denver International Airport (DEN) • Aircraft Hardstand Markings – Case Example #5—Multiple Airports (SFO and CLT) • Deicing Apron Markings – Case Example #6—Multiple Airports (ATL and CLE) • Airside Roadway Markings – Case Example #7—Multiple Airports (ATL, DEN, CVG) • Helicopter/eVTOL/Electric Aircraft Markings – Case Example #8—Multiple Airports (Dallas Vertiport and SUS) • CBP Apron Markings – Case Example #9—Multiple Airports (SAT and LEX) Airports were selected for case examples based on the uniqueness of the apron/ramp markings discussed in their survey responses. Several case examples include multiple airports in an effort to document different industry practices. Based on feedback from the project panel, two case examples on terminal gate area markings and taxilane/apron markings were completed. In addition to the airport case examples, interviews were conducted with A4A, United Airlines, Southwest Airlines, and an ALPA representative for the ALPA Airport and Ground Environment Group. While the case examples were being developed, it was determined that some airports have created unique apron/ramp marking standards, while others primarily establish apron/ramp markings standards through construction or apron remarking projects. For example, SEA maintains a document that describes current apron/ramp marking standards at the airport. This document is updated from time to time, and it is used when apron areas are remarked or changed. However, the majority of airports interviewed as part of the case examples do not C H A P T E R 4

36 Airfield Apron and Ramp Surface Markings maintain stand-alone apron/ramp marking standards as SEA does. Most airports that were inter- viewed established their initial apron/ramp marking standards through construction or com- prehensive apron remarking projects. Subsequently, the markings were sometimes amended or changed based on user feedback. However, in both situations, airports reported that it was chal- lenging to maintain documentation regarding ongoing changes that are made to their apron/ ramp marking scheme over the course of time. Marking changes are sometimes made but not documented for future reference. A side-by-side comparison of some of the markings found in these case examples is shown in Appendix C. 4.1 Terminal Gate Area Markings: Case Example #1— Cincinnati/Northern Kentucky International Airport The Cincinnati/Northern Kentucky International Airport (CVG) is a medium-hub commer- cial service airport located in Hebron, Kentucky. The airport has multiple commercial service airline terminals and is served by an array of airlines. An interview was conducted with CVG staff to discuss not only the various terminal gate apron markings used at the airport but also the specific challenges and opportunities related to markings in the terminal gate apron area. CVG staff reported that there are current variations in the terminal gate apron markings used at the airport. These variations stem primarily from different standards/requirements estab- lished by airlines for the gates that they lease or from which they commonly operate at the air- port. However, CVG is seeking to establish standards related to terminal gate apron markings to promote consistency between gates and to simplify maintenance activities. As part of this effort, the airport has established an Airfield Change Request form and process to support the proper review and approval of changes to the airport’s marking standards and practices. The form and process are applicable to portions of the airfield beyond the apron/ramp area. Figures 13 and 14 depict some of the unique marking practices associated with terminal gates at CVG. The variations are noted with numbers that correspond to the descriptions that follow. The following elements that are unique to each terminal gate marking schemes were noted: • #1. Coloration of Gate Designation Markings. The surface-painted gate designations shown in Figure 13 have a black inscription on a yellow background. The markings in Figure 14 have a yellow inscription on a black background. #1 #2 #3 #4 #5 #7 Figure 13. CVG terminal gate apron markings— Terminal B. Source: Google Earth.

Case Examples 37 • #2. Marking Patterns and Coloration for Alternative Lead-In Line Markings. The alter- native lead-in line markings shown in Figure 13 are yellow with a black outline, while the alternative lead-in line shown in Figure 14 is a black dashed line. • #3. Marking Coloration for Aircraft Safety Envelopes. The aircraft safety envelope shown in Figure 13 consists of white and red lines, while the aircraft safety envelope shown in Figure 14 consists of yellow and red lines. • #4. Alternative Aircraft Safety Envelope Is Painted in a Different Color. In Figure 13, the alternative lead-in line parking position is accompanied by a blue aircraft safety envelope marking that is separate from the safety envelope painted for the primary parking position. • #5. Coloration of Stop Line Designation Markings. In Figure 13, aircraft designations asso- ciated with each stop line have black text on a yellow background. In Figure 14, the same inscription is yellow with a black background. • #6. Emergency Ingress/Egress Area. While this area is not depicted in Figure 13, Figure 14 identifies a no parking area protected for the ingress/egress of emergency vehicles. The area is outlined in red and includes red crosshatching. Similar markings are used to designate no parking areas around fire hydrants in the terminal area. • #7. Supplemental Aircraft Safety Envelope Marking. A supplemental aircraft safety enve- lope marking is depicted in Figure 13 for aircraft that must stop closer to the terminal building for parking. This marking has the same coloration as the primary aircraft safety envelope but is dashed. In general, CVG staff stated that they would like to more fully standardize terminal gate apron markings at the airport, as the different marking schemes require additional maintenance and have the potential to create confusion. CVG staff stated that they would like to have painted markings for GSE storage areas to better delineate where GSE should park. The airport has regular discussions with their stakeholders (airlines, ground handlers, and so forth) regarding terminal gate apron markings as part of their monthly airfield safety meetings. 4.2 Terminal Gate Area Markings: Case Example #2— Hollywood Burbank Airport The Hollywood Burbank Airport (BUR) is a medium-hub commercial service airport located in Burbank, California. The airport has two commercial service airline terminals and is served by an array of airlines. An interview was conducted with BUR staff to discuss both the various #1 #2 #3 #5 #6 Figure 14. CVG terminal gate apron markings— Terminal A. Source: Google Earth.

38 Airfield Apron and Ramp Surface Markings terminal gate apron markings used at the airport and the specific challenges and opportunities related to markings in the terminal gate apron area. BUR’s terminal facility is in close proximity to both of the airport’s runways. This layout creates an array of operational challenges in the termi- nal environment that BUR has addressed with markings in the terminal apron area. Figure 15 depicts a portion of the existing apron area and identifies some of the unique markings that have been established. The following unique elements were noted in the terminal gate marking scheme: • #1. Push-back Guidance Markings. BUR has established blue dashed markings (outlined in white) behind several gates to provide guidance to ground crews regarding how aircraft should be oriented for taxi once they are pushed back from the gate. The orientation of the dashed marking shows the desired alignment of the body of the aircraft once it is pushed back. BUR reported that these markings have sometimes been confused with taxiway centerlines. Consequently, the airport plans to change this marking in the future. • #2. Aircraft Parking Limit Line. A solid white aircraft parking limit line has been established behind a portion of the terminal gate area to identify the boundary within which the tail of all parked aircraft must be. The line is also used as a point of reference for vehicle and GSE opera- tors. If operators see an aircraft taxiing on the terminal taxilane, they should position their apparatus behind the aircraft parking limit line until the aircraft passes. • #3. Pedestrian Walkways. BUR’s terminal does not have passenger boarding bridges and consequently loads and unloads passengers from aircraft via air stairs. As a result, the airport does have surface-painted pedestrian walkways at some gates. The walkways are outlined in white with no crosshatching. However, the airport reported that many of the pedestrian walkways are not used, as the airlines prefer to use vertical stanchions and personnel to guide passengers to and from the aircraft. • #4. Alternative Turning Lines. To provide enough flexibility for the types of aircraft that can use each gate, BUR uses alternative turning lines at some gates to aid aircraft in positioning themselves properly within the aircraft safety envelope. The primary turning line is shown in solid yellow, while the alternative line is dashed. • #5. Apron Control Point Marking. BUR has two apron control point markings that are used as a point of reference for aircraft holding and to guide the movement of aircraft in the terminal area. The markings conform to the guidelines in FAA AC 150/5340-1M (FAA 2019). All the terminal gates at BUR are common-use gates (not leased to an individual airline). However, there are variations in the terminal gate marking schemes based on the airline(s) that #1 #2 #3 #4 #5 Figure 15. BUR terminal gate apron markings. Source: Google Earth.

Case Examples 39 commonly use the gates. For example, some aircraft safety envelopes come to a point where the aircraft nose would be parked, while others are flat. Additionally, some parking positions include engine ingestion zone markings, while others do not. In 2019, the airport completed a terminal apron rehabilitation project. As part of the project, BUR coordinated closely with each airline on the terminal gate apron markings. Through this process, detailed policies were created on the types of aircraft permitted to use each gate and on the gate markings (dashed or solid) that each aircraft type should follow. To enable new airline entrants to better understand the markings, BUR provides the policies to these airlines before they begin service. Additionally, the airport meets with the chief pilot for new airline entrants to review and discuss the meaning and use of the established terminal area markings. BUR staff indicated that this practice has improved the familiarity of airline flight crews with the unique marking practices used at BUR. 4.3 Taxilane/Apron Markings: Case Example #3— Seattle-Tacoma International Airport The Seattle-Tacoma International Airport (SEA) is a large-hub commercial service airport located in Seattle, Washington. An interview was conducted with SEA staff to discuss both the various taxilane/apron markings used at the airport and the specific challenges and opportuni- ties related to markings in the taxilane apron area. Throughout the non-movement area at SEA, the majority of taxilane centerline markings are outlined in green instead of black. This marking practice was adopted to aid pilots in distinguish- ing between the limits of the movement and non-movement areas at SEA. The practice is shown in Figure 16. Other than where the taxilane centerline leads directly to the non-movement area boundary marking, the centerline is outlined in green. SEA staff reported that this marking practice has improved pilot awareness of whether they are in the movement or non-movement area. Additionally, around Concourse N at the north end of the terminal area complex, SEA has three parallel taxilane centerlines that are each outlined in a different color (green, blue, and orange). The terminal apron area at SEA is managed by a ramp tower, and the parallel taxilane Green Outlines for Taxilane Centerlines Figure 16. SEA non-movement area centerlines. Source: Google Earth.

40 Airfield Apron and Ramp Surface Markings centerlines separate aircraft traffic of various sizes that use the apron area. The different colors help ramp controllers to communicate to pilots about which taxilane centerline they should fol- low. A graphic of the taxilane centerline markings is shown in Figure 17, and an aerial image is shown in Figure 18. Simultaneous ADG III operations can occur on the orange and blue outlined taxilane centerlines, while the green can be used for aircraft larger than ADG III. To aid ground crews in pushing back aircraft into the proper position, SEA has also estab- lished surface-painted push-back diamonds along some taxilane areas. The diamonds represent the preferred location for the aircraft nose upon push-back. A graphic of the diamonds is shown in Figure 17. SEA parallel taxilane centerline specifications. Source: Port of Seattle 2021. Green Outlines Orange Outlines Blue Outlines Figure 18. SEA parallel taxilane centerlines. Source: Google Earth.

Case Examples 41 Figure 19, and an aerial image is provided in Figure 20. The order of the diamond outline colors may vary. In addition, to provide guidance to pilots and ground crews when pushing back an aircraft from the gate, SEA has established engine start position markings. The markings indicate to pilots and ground crews the point at which it is safe to start the engines of an aircraft. A graphic of the engine start marking is shown in Figure 21, and a photo is provided in Figure 22. In some taxilane areas, SEA has also installed surface-painted hold signs where aircraft should hold before receiving non-movement area taxi clearance from ramp control. A graphic of the hold marking is shown in Figure 23, and an aerial photo is provided in Figure 24. SEA maintains a set of published standards related to apron/ramp markings at the airport. The standards include taxilane apron markings as well as terminal gate apron markings. The standards are updated regularly, and any deviations from the standards require a safety risk Figure 19. SEA push-back diamond specifications. Source: Port of Seattle 2021. Push-Back Diamonds Push-Back Diamonds Figure 20. SEA push-back diamonds. Source: Google Earth.

42 Airfield Apron and Ramp Surface Markings Figure 22. SEA engine start markings. Source: SEA staff. Figure 21. SEA engine start marking specifications. Source: Port of Seattle 2021.

Case Examples 43 Figure 23. SEA hold marking specifications. Source: Port of Seattle 2021. Hold Marking Figure 24. SEA hold marking. Source: Google Earth. assessment (SRA) under the airport’s Safety Management System (SMS) program. SEA collabo- rates with Jeppesen to ensure that the meaning of its various apron/ramp markings are commu- nicated to pilots through Jeppesen’s 10-7 pages, which airlines typically provide to their pilots. SEA staff reported that some of their biggest challenges related to taxilane/apron markings are ensuring that they are properly maintained and that apron areas do not become overly busy with markings. 4.4 Taxilane/Apron Markings: Case Example #4— Denver International Airport The Denver International Airport (DEN) is a large-hub commercial service airport located in Denver, Colorado. An interview was conducted with DEN staff to discuss both the various taxilane/apron markings used at the airport and the specific challenges and opportunities related to markings in the taxilane apron area. Similar to SEA, DEN outlines some of its parallel taxilane centerlines in a different color (other than black) to aid pilots in distinguishing between different taxilane centerlines. The taxilane

44 Airfield Apron and Ramp Surface Markings centerlines outlined in a different color are primarily used as bypass taxilanes that allow aircraft to pass around other aircraft that are using the main taxilane. Figure 25 shows this layout. The terminal apron area at DEN is managed by a ramp tower, and the different colors help ramp controllers communicate to pilots which taxilane centerline they should follow. However, instead of outlining both sides of the centerline with a different color, only one side of the pri- mary and secondary centerlines are outlined. The two colors used at DEN are purple and green. This practice is depicted in Figures 26 and 27. DEN has also established FOMO lines along many of its terminal parking areas to protect the TLOFA associated with the primary taxilane. It does this by providing a visual reference to ground crews and the ramp tower regarding the boundary that aircraft should not be pushed past during a push-back operation. If an aircraft is not pushed beyond the FOMO marking, the taxilane adjacent to the FOMO marking remains usable. A standard photo and an aerial photo of the FOMO marking are shown in Figures 28 and 29. Main Taxilane Centerline Outlined in Black Secondary Taxilane Centerline Outlined in a Different Color Figure 25. DEN taxilane centerlines outlined in a different color. Source: Google Earth. Figure 26. DEN taxilane centerline with purple outline. Source: Google Earth.

Case Examples 45 Figure 27. DEN taxilane centerline with green outline. Source: DEN staff. FOMO Marking Figure 29. DEN FOMO marking aerial. Source: Google Earth. FOMO Marking Figure 28. DEN FOMO marking. Source: DEN staff.

46 Airfield Apron and Ramp Surface Markings 4.5 Taxilane/Apron Markings: Other Examples A number of other unique taxilane/apron marking practices were identified as part of the synthesis, but full case examples were not completed. These unique taxilane/apron markings are: • Dashed Taxilane Centerlines. Multiple airports reported using dashed taxilane centerlines in combination with solid taxilane centerlines to communicate to pilots the centerline that they should follow based on the size of their aircraft. Figure 30 is an example of this practice at Miami International Airport (MIA). The dashed taxilane centerline is used by widebody aircraft, while the solid centerlines are used by Boeing 757 or smaller aircraft. • Diamond Imposed Taxilane Centerlines. The San Francisco International Airport (SFO) uses a taxilane centerline imposed with yellow diamonds to denote the centerline that should be used by Group VI aircraft. Figure 31 depicts this practice. • Different Colors for Taxilane Centerlines. The San Marcos Regional Airport (HYI) is a general aviation airport located in San Marcos, Texas. The airport painted the taxilane center- lines on its primary apron in different colors to aid pilots in better navigating the large expanse of pavement. This practice is shown in Figure 32. • Different Colors of Apron Designation Markings for Aircraft Holding. Several airports use different colors of markings with alpha-numeric designations to help identify locations where aircraft may be asked to hold in the non-movement area. For example, SFO uses blue markings with a white inscription to identify potential holding points in the non-movement area. Figure 33 depicts this practice. • “T” Markings to Identify the Positioning of Aircraft When Pushed Back from the Gate. Some airports reported that they installed small surface-painted “T” markings to help ground crews identify the desired position of the nose wheel of an aircraft upon push-back. An example of this marking at Dallas/Fort Worth International Airport (DFW) is shown in Figure 34. • Wingspan Limitation Markings. Several airports reported that they installed wingspan or ADG limitation markings adjacent to taxiway centerlines to communicate to pilots any wing- span restrictions. An example of this marking at the Greenville-Spartanburg International Airport (GSP) is shown in Figure 35. Figure 30. MIA dashed taxilane centerline markings. Source: Google Earth.

Case Examples 47 ADG VI Diamond Centerline Figure 31. SFO diamond ADG VI taxilane centerline marking. Source: Google Earth. Red Centerline Figure 32. HYI red taxilane centerline marking. Source: Google Earth.

48 Airfield Apron and Ramp Surface Markings Figure 33. SFO blue holding boxes. Source: Google Earth. T Marking T Marking Figure 34. DFW T-markings. Source: Google Earth. Figure 35. GSP wingspan restriction markings. Source: Google Earth.

Case Examples 49 4.6 Aircraft Hardstand Markings: Case Example #5— San Francisco International Airport and Charlotte Douglas International Airport Through the industry survey, SFO and the Charlotte Douglas International Airport (CLT) were identified as having used some unique aircraft hardstand marking practices. These prac- tices are discussed as part of this case example. SFO is a large-hub airport located in San Francisco, California, that serves a variety of domestic and international flights. SFO has hardstand aircraft parking positions in its terminal area that are used for a variety of purposes, including aircraft parking, holding, and passenger loading/ unloading. As a result, these areas contain a number of unique markings to support the safety and efficiency of the operation. The northern hardstand area and some of the markings used at this location are shown in Figure 36. The following unique elements related to the hardstand marking scheme were noted: • #1. Full Aircraft Safety Envelope. SFO uses a full aircraft safety envelope marking around some hardstand positions. The markings consist of a red line outlined by two white lines. The majority of hardstand locations that were reviewed as part of this synthesis did not include aircraft safety envelope markings similar to these markings. SFO does not use full aircraft safety envelopes on all hardstand parking locations. • #2. GSE Staging-Only Markings. GSE staging area markings have been established to identify the specific location where GSE should be parked/staged. The markings consist of a white dashed line that borders the aircraft safety envelope on one side and is surrounded by a solid white line where the dashed does not abut the aircraft safety envelope. The words “GSE STAGING ONLY” are painted in the center of each area. • #3. One-Way Vehicle Roadway Markings. To support the safe and efficient flow of vehicles around the hardstand area, one-way roadways have been established. These roadways are denoted with white arrows located in the center of the vehicle service road (VSR). • #4. Keep Clear Markings. The words “KEEP CLEAR” are painted in large letters on the areas between the aircraft safety envelopes to ensure that vehicles and equipment are not parked in this location. • #5. Fuel Truck Only Markings. Adjacent to the hardstand area, two solid white boxes are painted on the surface to identify where fuel trucks should park. The words “FUEL TRUCK PARKING” are painted in white block letters in the middle of the area. #1 #2 #3 #4 #5 Figure 36. SFO hardstand markings—1. Source: Google Earth.

50 Airfield Apron and Ramp Surface Markings Figure 37 depicts a second hardstand parking area at SFO that includes some additional markings. The following unique elements related to the hardstand marking scheme were noted: • #1. Underground Facility Node Protected Area. Large red boxes are painted around under- ground facility connection points (such as fuel hydrants) to aid pilots and ground crews in identifying and avoiding these locations. • #2. Aircraft Apron Hold Positions. The blue boxes with white inscriptions that are co-located with a blue dashed line identify locations where aircraft may be required to hold prior to taxiing to a gate. • #3A and #3B. Bi-Direction Aircraft Lead-In Line. The lead-in lines at this location are bi-directional, meaning that aircraft can be parked with their nose facing toward or away from the GSE. This was done to provide flexibility with respect to the size of aircraft that can use the hardstand location. Figure 38 depicts a third aircraft hardstand parking area at SFO. This area is used to hardstand aircraft for passenger loading/unloading via buses. Consequently, the area includes markings that show the specific locations where buses should park. The markings consist of the words “BUS ONLY” in large block letters. The area is also outlined in green, and “piano key” style white and green stripes identify the area in which passengers should load/unload from the buses. Aircraft safety envelopes are not provided in this location to allow for maximum flexibility with respect to the size of aircraft that can park in this location. #1 #2 #3B #3A Figure 37. SFO hardstand markings—2. Source: Google Earth. Bus Parking Areas Figure 38. SFO hardstand markings—3. Source: Google Earth.

Case Examples 51 Figure 39 depicts a cargo hardstand apron at SFO that is located adjacent to the passenger terminal area. This area includes a number of unique hardstand markings but does not include aircraft safety envelopes. The following unique elements related to the cargo hardstand marking scheme were noted: • #1. Keep Clear Areas. Areas that are expected to remain clear and free from parked aircraft or equipment are denoted with white crosshatching. The words “KEEP CLEAR” are painted multiple times on every third line. • #2. Directional Signage for Parking Locations. Surface-painted signage aids aircraft in locating their hardstand parking position. These signs are yellow with a black inscription. They are painted adjacent to the lead-in line that would direct an aircraft to its parking position. • #3. Secured Area Boundary Line. A red crosshatched area denotes the limits of the secured area associated with the passenger terminal facility. Vehicles and personnel must not cross this line. Personnel and equipment are required to pass through a guard post located south of the area shown in the figure. Figure 40 depicts a general aviation hardstand apron at SFO. This apron is located on the north end of the airfield. #1 #2 #3 Figure 39. SFO hardstand markings—cargo apron. Source: Google Earth. #1A #2 #1B Figure 40. SFO hardstand markings—general aviation area. Source: Google Earth.

52 Airfield Apron and Ramp Surface Markings The following unique elements related to the general aviation (GA) hardstand marking scheme were noted: • #1A and #1B. Primary and Secondary Lead-In Lines. Similar to terminal gates, primary aircraft parking positions are denoted by solid yellow lines. Alternative parking alignments are identified with a dashed yellow line. • #2. Security Line. This marking consists of parallel red lines with the words “SECURITY LINE DO NOT CROSS” painted in between the lines. The line informs personnel that they should not cross it unless they are properly badged. Charlotte Douglas International Airport (CLT) is a large-hub airport located in Charlotte, North Carolina. The airport has a western hardstand apron employing some unique marking practices that enable the apron to be used by various combinations of aircraft and for different purposes. The apron is shown in Figure 41. The apron has three distinct marking types that correlate with the size of aircraft that are authorized to use each parking location, with the manner in which the aircraft must be parked, or both (e.g., taxi or towed). The following is a short description of each marking type: • #1. T-Parking Positions. All aircraft parking positions that are depicted in orange and denoted with a “T” require that the aircraft be towed to/from the parking location. Aircraft may taxi onto the parking location if wing walkers are used. Otherwise, aircraft are not allowed to taxi to/from these positions. Narrowbody aircraft may use these spots. • #2. H-Parking Positions. All aircraft parking positions depicted in yellow and denoted with an “H” can be used by narrowbody aircraft waiting either to park at a gate or for depar- ture clearance. Aircraft are allowed to taxi to/from these parking positions under their own power. Aircraft may park nose to tail in this area or with their nose facing out. If aircraft park nose to tail, the first aircraft must move before the second aircraft (e.g., the one behind it) can move. • #3. HX-Parking Positions. All aircraft parking positions depicted in yellow and denoted with an “H” at the beginning and an “X” at the end can be used by widebody aircraft waiting either to park at a gate or for departure clearance. Aircraft are allowed to taxi to/from these parking positions under their own power. The lead-in lines associated with all these markings are yellow. However, dashed lead-in lines are used to denote locations to be used by widebody aircraft. The parking designations associ- ated with the “H” and “HX” positions are bi-directional, meaning that the aircraft can park facing either direction. Figures 42, 43, and 44 show the various combinations of aircraft that can use the parking positions. In Figure 42, the aircraft parking on the orange “T” spots would be required to be #1 #2 #3 Figure 41. CLT west hardstand markings. Source: Google Earth.

Case Examples 53 Figure 42. CLT west hardstand T-markings. Source: CLT staff. Figure 43. CLT west hardstand H-markings. Source: CLT staff.

54 Airfield Apron and Ramp Surface Markings towed to/from the parking location or could taxi to the location if wing walkers were present. In Figure 43, the aircraft parking on the yellow “H” spots would be allowed to taxi to/from the parking position. In Figure 44, the aircraft parking on the yellow “HX” spots would be allowed to taxi to/from the parking position. The airport has established an aircraft parking matrix that can be used to determine which spots are not available when aircraft are occupying adjacent spots. The same marking coloration standards (e.g., orange for tow/wing walkers and yellow for taxi) are used at other hardstand locations in the terminal area. The north hardstand, shown in Figure 45, has the same marking scheme. However, the spots are denoted with Ns instead of Ts because the hardstand is in the north apron. Figure 44. CLT west hardstand HX-markings. Source: CLT staff. Tow In/Out Spots Taxi In/Out Spots Figure 45. CLT north hardstand markings. Source: Google Earth.

Case Examples 55 4.7 Deicing Apron Markings: Case Example #6— Hartsfield-Jackson Atlanta International Airport and Cleveland-Hopkins International Airport During deicing operations, deicing aprons can play an important role in maintaining an air- port’s operational capacity. Based on the results of the industry survey, several airports use a number of common deicing apron marking practices as set forth in FAA AC 150/5300-14D. However, to overcome specific challenges, some airports have established marking practices that are unique to deicing. ATL uses green markings with white outlines for its deicing aprons. Pilots are directed to fol- low these centerlines to have their aircraft deiced. Each spot includes a unique letter identifier. The bracket markings (e.g., four right-angled lines) identify where deicing trucks should be posi- tioned during deicing operations. Examples of these deicing markings are shown in Figures 46 and 47. Each deicing pad at the airport has been established to accommodate aircraft of different sizes. For example, the deicing pad shown in Figure 46 is intended to be used by aircraft up to the size of a Boeing 757. A close-up picture of the marking is shown in Figure 48. Similar to the markings at other airports, the intent of these markings is communicated to pilots via the Jeppesen 10-7 pages. ATL staff indicated that the markings have not reportedly created any confusion. While not a subject of this case example, DEN also uses green taxilane centerlines to support aircraft deicing operations. However, these centerlines are used only under Deicing Centerline Spot Designation Deicing Vehicle Area Boundaries Figure 46. ATL deicing apron markings—1. Source: Google Earth. Deicing Centerline Spot Designation Deicing Vehicle Area Boundaries Figure 47. ATL deicing apron markings—2. Source: Google Earth.

56 Airfield Apron and Ramp Surface Markings specific wind conditions when the regular deicing apron markings cannot be used. These deicing apron markings are shown in Figure 49. The Cleveland-Hopkins International Airport (CLE) has a large deicing pad that serves as the primary deicing facility for the majority of aircraft that use the airport. The deicing pad is shown in Figures 50 and 51. Up to two ADG III aircraft may park nose to tail using each of the taxilane centerlines designated as 1, 3, 4, 6, 7, and 9 (i.e., 12 total aircraft). Aircraft that are ADG IV and above must use the taxilane centerlines designated as 2, 5, and 8. Only one aircraft that is ADG IV or above can use each of these centerlines at a time. When the taxilanes designated as 2, 5, or 8 are used by aircraft that is ADG IV or above, the adjacent centerlines (1, 3, 4, 6, 7, and 9) are not available. A unique marking practice related to the pad is that apron entrance point markings as described in FAA AC 150/5340-1M are used to denote each centerline leading into the deicing Figure 48. ATL deicing apron markings—3. Source: ATL staff. Alternate Deicing Marking Figure 49. DEN alternate deicing markings. Source: DEN staff.

Case Examples 57 pad. CLE staff indicated that the markings associated with the deicing pad have not reportedly created any confusion for pilots. 4.8 Airside Roadway Markings: Case Example #7— Hartsfield-Jackson Atlanta International Airport, Denver International Airport, and the Cincinnati/ Northern Kentucky International Airport Airside roadway markings can play a critical role in the safety of vehicle and pedestrian operations in the airfield environment. While standards for airside roadway markings are set forth in FAA AC 150/5340-1M, some airports have adopted unique markings practices. For example, ATL uses a red/white zipper marking as shown in Figure 52 and 53 to denote the limits of the non-movement area. The marking is used in place of a non-movement boundary mark- ing. Figure 53 also shows a new surface-painted marking recently added at ATL. The marking is a large sign that says, “CAUTION ACTIVE TAXIWAY NO VEHICLE TRAFFIC.” This sign has been painted in an area that was historically prone to vehicle/pedestrian deviations. Prior to the installation of the sign, vehicle operators would frequently cross into the movement area without authorization. Figure 50. CLE deicing apron markings—1. Source: Google Earth. Figure 51. CLE deicing apron markings—2. Source: Google Earth.

58 Airfield Apron and Ramp Surface Markings ATL also uses surface-painted “STOP FOR AIRCRAFT” signs along its airside service roads to improve drivers’ awareness when they are entering areas in which aircraft may be crossing. Examples of these signs are shown in Figure 54 and 55. Additionally, behind the gates operated by Delta Air Lines, ATL has a surface-painted red line with a white inscription that says “STOP.” The line is painted behind aircraft gates adjacent to the vehicle service road to remind vehicle operators to stop and look for traffic before accessing this road. The line is shown in Figure 56 and 57. To restrict access to certain areas, DEN has established limited access routes (LARs) within its network of vehicle service roads. The LARs are marked with a vehicle roadway centerline that is outlined in blue, as shown in Figure 58. Access to LARs is restricted to individuals who have been trained specifically to operate in these areas. LARs are primarily located along vehicle services roads that connect to active taxiways or that are adjacent to navigational aids (NAVAIDs). Red/White Zipper Marking Figure 52. ATL red/white zipper markings—1. Source: Google Earth. Figure 53. ATL red/white zipper markings—2. Source: ATL staff.

Case Examples 59 Figure 54. ATL stop for aircraft—yellow. Source: ATL staff. Figure 55. ATL stop for aircraft—white. Source: ATL staff. Figure 56. ATL stop line—1. Source: ATL staff.

60 Airfield Apron and Ramp Surface Markings Similar to the LARs at DEN, CVG has outlined some of its vehicle service roads in red, as shown in Figure 59. This is done where vehicle service roads cross active taxilanes to heighten driver awareness that they are crossing an area in which aircraft could be traversing. On each side of the vehicle service road where it crosses a taxilane, there is a surface-painted sign that says, ““YIELD TO AIRCRAFT.” Beyond the case examples, multiple airports have surface-painted informational signs for drivers; the signs vary in layout and form. • Speed Limit Signs. The form and layout of surface-painted speed limit signs vary from air- port to airport. Some airports have signs that show the speed limit and followed by the letters “MPH.” Others, such as SFO, use a white circle with a black inscription showing the speed limit, as shown in Figure 60. • Stop Signs. Some airports surface paint the word “STOP” in white block letters, shown in Figure 60, while other airports paint red stop markings, as shown in Figure 59 (CVG). Additionally, SEA and the Buffalo Niagara International Airport (BUF) have a vehicle control line that is located inside the non-movement area and provides a boundary that vehicles without proper authorization/training should not cross. Figure 61 shows the vehicle control line at SEA. Stop Line Figure 57. ATL stop line—2. Source: Google Earth. Figure 58. DEN limited access route. Source: DEN staff.

Case Examples 61 Vehicle Stop Yield to Aircraft Red VSR Outline Figure 59. CVG vehicle service road taxilane crossing. Source: DEN staff. Speed Limit Stop Marking Figure 60. SFO speed limit and stop markings. Source: Google Earth. Vehicle Control Line Figure 61. SEA vehicle control line. Source: Google Earth.

62 Airfield Apron and Ramp Surface Markings 4.9 Helicopter/eVTOL/Electric Aircraft Markings: Case Example #8—Dallas CBD Vertiport and Spirit of St. Louis Airport Some apron/ramp areas may have unique markings related to helicopter operations, eVTOLs, and/or electric aircraft. This case example includes a summary of the helicopter markings that were identified at the Spirit of St. Louis Airport (SUS), which is a GA airport in Chesterfield, Missouri, and the Dallas CBD Vertiport (49T) located at the Convention Center in Dallas, Texas. No airports reported in the survey that they have markings specific to eVTOLs or electric aircraft. Multiple airports did, however, report in the survey that they have some markings specific to helicopter operations. Nevertheless, the level of detail and alignment with the marking stan- dards in FAA AC 150/5390-2C (FAA 2012) varies. SUS has two helipad markings located on its fixed-base operator (FBO) apron that are used by helicopter traffic. The markings include the helipad designation, FATO, and TLOF markings, as shown in Figure 62. The Dallas CBD Vertiport facility is an elevated heliport/vertiport facility that is primarily used by helicopters. The facility includes two landing positions and five aircraft parking posi- tions. According to vertiport personnel, the marking scheme for this facility was originally based on guidelines provided in FAA AC 150/5390-3: Vertiport Design, which was canceled in 2010. The facility and its markings are shown in Figure 63. Some unique marking elements at the vertiport are: • #1. Heading Designation. Each landing position has a designated heading that aircraft should follow when approaching that position. The landing position painted with a “4” indicates that aircraft should approach the position using a heading of 40 degrees. The “31” painted at the other landing position shown in Figure 63 indicates that aircraft should approach the position using a heading of 310 degrees. • #2. Weight-Bearing Capacity. Each landing position has a designated weight-bearing capac- ity of 43,000 pounds, as represented by the surface-painted “43.” • #3. Touchdown and Positioning Triangle. Similar to a TDPC, each landing position has a triangle that is oriented to show the direction from which aircraft should approach and how they should orient their helicopter when landing. • #4. Parking Positions. Five aircraft parking positions are identified with white T-markings and are outlined with a box outlined in white. • #5. Chevrons. Yellow chevrons have been painted adjacent to the building to show areas that are not available for helicopters. Figure 62. SUS helipad markings. Source: Google Earth. TLOF FATO Helipad Designation Marking

Case Examples 63 4.10 CBP Apron Markings: Case Example #9— San Antonio International Airport and Blue Grass Airport Multiple airports reported that they use blue apron/ramp markings related to CBP and CBP facilities. In general, the blue CBP markings reviewed for this synthesis were used to identify the location where general aviation aircraft should park when they are clearing customs. At Blue Grass Airport (LEX), a blue box is painted on the apron. Aircraft that are clearing customs are supposed to park inside the box, and only CBP personnel are allowed inside the box when an aircraft is parked there. This marking is shown in Figure 64. Figure 63. Dallas CBD vertiport. Source: Google Earth. #1 #3 #2 #4 #5 Figure 64. LEX CBP blue aircraft parking box. Source: Google Earth. Blue CBP Box

64 Airfield Apron and Ramp Surface Markings San Antonio International Airport (SAT) also has blue apron/ramp markings associated with its general aviation CBP facility. However, unlike the markings at LEX, SAT’s markings provide guidance to pilots regarding the desired parking alignment of their aircraft. These markings are shown in Figure 65. 4.11 Industry Interviews: Airline Pilots Association, United Airlines, A4A, and Southwest Airlines As part of the study process, interviews were conducted with A4A, United Airlines, South- west Airlines, and an Airline Pilots Association (ALPA) representative from the ALPA Airport and Ground Environment Group. With respect to apron/ramp markings, the following points/ recommendations were made by each group: • ALPA Airport and Ground Environment Group – Importance of Jeppesen 10-7 pages—Airports should notate any unique apron mark- ings in the Jeppesen 10-7 pages. This will ensure that the information is provided to flight crews. – Show wingspan restriction in feet—The interviewee recommended that airports show any surface-painted wingspan restriction signs in feet instead of by ADG. Most pilots do not know the wingspans associated with various ADG categories. – Lead-in lines from taxilane centerline—The interviewee indicated that pilots generally prefer lead-in lines that stretch all the way from the taxilane centerline to the stop bar at the gate. This practice reduces the amount of judgment a pilot must exercise when pulling into a terminal gate. • United Airlines – Airlines have different marking requirements—Each airline has its own unique gate marking standards and separation requirements. Some airlines have more stringent sepa- ration requirements than others. – Standardization would be beneficial—More standardization in apron/ramp markings across the industry would likely be beneficial in terms of safety. • A4A – Marking congestion concerns—Multiple participants in the A4A interview identified concerns related to an overabundance of apron markings. They stated that airports some- times have too many apron markings in a given area, which can be confusing for pilots. CBP Parking Location #1 CBP Parking Location #2 Figure 65. SAT CBP blue aircraft parking markings. Source: Google Earth.

Case Examples 65 The participants recommended that airports work with their airline partners to ensure that the apron markings at their airport are not overly complex. – Increased standardization would be beneficial—Similar to the feedback provided by United Airlines, all the members of the A4A interview panel indicated that greater standardization related to apron/ramp markings across the industry would be beneficial. – Marking coloration—The interview participants were asked whether certain colors of markings are more difficult to see. They responded that, to their knowledge, no specific colors are better or worse regarding visibility. However, they recommended that the effective- ness of various marking colors should be further researched. • Southwest Airlines – Airports should coordinate with airlines on terminal apron marking decisions—When airports revise or make changes to their terminal apron marking scheme, it is typically beneficial for airlines to be engaged in the decision-making process. – Airline safety risk management processes—Airlines typically have a safety risk manage- ment process that may need to be engaged if a terminal apron gate that they will be using does not meet their marking standards.