cee 4674 airport planning and design geometric...
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CEE 4674 – Airport Planning and Design (copyright A. Trani)! 1 1
Dr. Antonio A. Trani Professor of Civil Engineering
Virginia Polytechnic Institute and State University
February 25, 2009
Blacksburg, Virginia
! CEE 4674 Airport Planning and Design
Geometric Design I
Addendum 1
CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Organization of this Presentation
• Geometric design standards for runway exits • Examples
• Design rationale for taxiways and taxilanes
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CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Geometric design Standards for Runway Exits
• Sources:
• FAA AC 5300-13 (Chapter 3)
• ICAO Aerodrome Manual Volumes 1 and 2
• Design principle:
• Provide ample space for aircraft to maneuver out of the runway
• Make the runway exits easily identifyable
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CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Right-Angle Exits
• Baseline centerline radius is 250 feet
• Pavement edge radius varies according to runway width
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CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Sample Implementation (ATL)
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R = 250 feet!
Runway!(150 feet wide)!
Parallel Taxiway!
90 degree!Runway Exit!
Source: Google Earth!
CEE 4674 – Airport Planning and Design (copyright A. Trani)!
45 Degree Angle Runway Exit
• Nominal 800 feet centerline radius
• 600 feet pavement edge radius
• Old design – FAA has dropped diagram from AC 5300-13
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CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Issues with 45 Degree Runway Exits
• Narrow width at tangency point (only 40 feet)
• Only useful for busy general aviation airports
• Since the FAA has dropped discussion of this design in the latest releases of the AC 5300-13 the geometry should be use with caution
• The 30 degree standard design seems to be favored in case peak operations exceed 30 per hour
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CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Acute Angle or High-Speed Runway Exit 30 Degree (Old Standard)
• Nominal 1800 feet centerline radius
• 1600 feet pavement edge radius
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CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Acute Angle or High-Speed Runway Exit 30 Degree (New Design)
• Nominal 1400 feet centerline spiral
• Can use the FAA computer program AD42.exe application for design (companion computer program to AC 5300-13)
• See example on page 48-1 in Chapter 4 of AC 5300-13
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CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Specification of a High-Speed Runway Exit
• x-y coordinates of centerline
• Left and right offset distances from the centerline
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CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Specification of High-Speed Runway Exit
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CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Example in AC 5300-13 (see page 48-1 in FAA AC 5300-13)
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CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Example Problem in AC 5300-13
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CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Example Problem in AC 5300-13
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CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Explanation
• The intersection angle is negative (-30 degrees) so this turn is to the left
• The offsets (both right and left) decrease as a function of station length to make the transition the runway exit width from 150 to 75 feet
• The centerline angle increases from zero at the start of the runway exit point to 30 degrees as required by the geometry
• The steering angle provides a measure of how much effort is required by the nose gear to keep with the centerline geometry
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CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Example Implementation (ATL) 30 Degree Angle Runway Exit
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Source: Google Earth!
1400 foot spiral!
Runway!(150 feet wide)!
Parallel Taxiway!
250 feet radius !reverse geometry!
800 feet radius!
CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Issues with 30 Degree Runway Exits
• The FAA recommends a minimum runway-taxiway separation of 600 feet for High-Speed runway exits
• Some airport have used 30 degree runway exits with down to 400 feet (avoid!)
• The result is low exits speeds and possible issues with busting hold lines
• Be careful and try to provide the minimum 600 foot recommended distance
• Limited pilot visibility while crossing active runways
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CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Sample Limited Visibility on High-Speed Runway Exit
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Final turning angle at hold line = 30 degrees!
CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Example of Limited Visibility due to Short Runway-Taxiway Distance
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CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Airbus A340-600 Visibility from Cockpit
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Source: Airbus!
CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Example of Limited Visibility Driven by Hold Line Location
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• Before the aircraft nose reaches the hold line, the aircraft wingtip violates the hold line distance!
CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Taxiway-Taxiway Junctions
• For dimensions consult FAA 150/5300-13 Table 4-2
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CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Table 4-2 in AC 5300-13 Taxiway Fillet Dimensions
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CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Taxiway-Taxiway Junctions
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• Sample solution shown for ADG VI
• For other groups consult FAA 150/5300-13 Table 4-2
CEE 4674 – Airport Planning and Design (copyright A. Trani)!
Sample Junction
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