INTRODUCTION
During the Second World War, many military airports were built in the United States (USA) and
Canada for logistics, air support and fighter pilot training. After the war, these airports were
converted to civilian airports and handed over to the Civil Aeronautical Administration (CAA)
and the Civil Aeronautics Board (CAB), the forerunner of the present Federal Aviation
Administration (FAA) for operation and management. The land around most of these airports
was not used for residential use until late in the 1970s. As builders began to construct houses on
land adjacent to the airport, these airports found that they were sitting in the middle of residential
areas where local residents complained about noise to the FAA. Environmental control and
noise pollution became a significant concern, and many airports were forced to curtail nighttime
operations. This happened not only in the USA, but also in England and Europe. Even today,
Dallas/Fort Worth (DFW) airport shuts down specific runway operations to reduce noise along
certain arrival or departure routes after 9 p.m. At Heathrow airport, London, United Kingdom
(UK), and several other European airports, no arrival is scheduled before 6 a.m. in the morning.
This led to the development of noise monitoring systems and other enforcement technologies to
monitor airport operations and protect people living close to the airport property. Scientific
advancements in noise monitoring include determining the height that an aircraft arrives or
departs from an airport. ASR-9 radar and other surface monitoring systems provide information
on the location of aircraft on the approach path or departure route near the airfield.
Runway safety, especially runway incursions, poses a significant operational concern for
airports. At DFW and most other parallel runway airports, planes are currently forced to cross
active runways when either arriving or departing. Since this creates conflict points, the risk of a
runway incursion or collision hazard is higher for this type of airport operations. Recently, a
new strategy, the perimeter taxiway (PT) or end around taxiway (EAT), has been
developed to
try to address these safety concerns and possibly improve operations.
In 1996, this concept first emerged as a possible solution to improve runway safety, reduce
runway incursion opportunities and to increase runway capacity. Leigh Fisher Associates (LFA)
[1] studied the concept and proposed several design alternatives for use at DFW, with regard to
location, type and speed of aircraft on the PT. Davis [2,3] analyzed the concept in detail in 2002
and 2003, to determine the Obstruction Free Zone (OFZ) criteria and recommended that the PT
centerline be set at 2,650 from the end of the north-south parallel runways (18R/36L, 18L/36R,
17R/35L, and 17C/35C) at DFW. Further detailed evaluation occurred at the NASA Ames B747
flight simulator at Moffet Field in California in 2003 [4] and a decision by the FAA/Airport
Operations Safety Committee (AOSC) in 2006 [5, 6] led to the start of construction of the PT on
the SE quadrant of the airfield at DFW (Figure 1).
Establishing the height that an aircraft will fly over the PT during the arrival (descent) and the
departure (climb) phase is critical for safe operation. To accurately determine the aircraft height
over the PT centerline, the authors use historical, real time flight data, which is maintained by the
DFW/Environmental Affairs Department (EAD). The data is for five separate days with one day
selected at random for each year from 2001 to 2005; the selected days are 1-3-2001, 7-17-2002,
8-6-2003, 7-29-2004 and 8-2-2005. The data collected has information on date, time, flight
number, aircraft type, runway assignment, navigational fix, type of operation (arrival or
departure) and elevation above Mean Sea Level (MSL). The average ground elevation (GL) of
the airport is set at 600 feet above MSL by software for aircraft height computations.
Satyamurti and Mattingly
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