If you haven’t noticed, last month Addison Airport removed a light pole and sign from the north side of the Jetport ramp and the south side of Taxiway Victor. Perhaps the pilots of larger aircraft, like the Gulfstream G650, with its 99-foot-7-inch wingspan, or the Boeing 737 variants, whose wings span from 93 to 117 feet 5 inches (with winglets), were the first to notice—and appreciate—the added width.
Removing the sign was another example of the small, dynamic details that are part of airport operations. In airport parlance it is an Object Free Area (OFA). FAA Advisory Circular 150/5300-12, Airport Design, defines it as “an area on the ground centered on a runway, taxiway, or taxilane centerline provided to enhance the safety of aircraft operations by having the area free of objects, except for objects that need to be located in the OFA for air navigation or aircraft ground maneuvering purposes.”
The aircraft using the pavement determine how much horizontal and vertical area must be object free. Aircraft are sorted into six Airplane Design Groups by their wingspan and total height, measured in feet. Group I starts the scale with wingspan less than 49 feet and total height of less than 20 feet. Membership in Group VI calls for a wingspan of 214 to less than 262 feet and a height of 66 to less than 80 feet. The G650 and 737 are in Group III, for aircraft with wingspans of 79 to less than 118 feet and heights of 30 to less than 45 feet.
Technically, Victor is a “taxilane” because it connects aircraft parking areas to taxiways, in this case Taxiway Alpha, which is a “defined path established for the taxiing of aircraft from one part of the airport to another.” For Group III, the taxilane OFA width is 162 feet and the taxiway requirement is 186 feet.