Page 89 - Planning and Design of Airports

Air craft Characteristics Related to Airport Design 61

“2D/2D2” “3D” “2D/3D2”
Double dual tandem Triple tandem Dual tandem plus
Boeing 747 Boeing 777 triple tandem
Airbus A-380
FIGURE 2-4 Complex landing gear confi gurations (Federal Aviation Administration).

The complexity of landing configurations prompted the FAA to adopt
standard naming conventions for aircraft landing gear configurations
[60]. Examples of this naming convention are represented in quotes in
Figs. 2-3 and 2-4.
The landing gear configuration plays a critical role in distributing
the weight of an aircraft on the ground it sits on, and thus in turn has
a significant impact on the design of airfield pavements. Specifically,
the more wheels on a landing gear, the heavier an aircraft can be and
still be supported on a ramp, taxiway, or runway of a given pavement
strength.

Aircraft Weight
While the concept of aircraft weight may be thought to be a simple
one, the measurement of the weight of a given aircraft is actually rel-
atively complex. An aircraft will in fact be measured with a certain
number of weight measurements, depending on its level of loading
with fuel, payload, and crew, and assigned maximum allowable
weight values for takeoff, landing, and at rest.
These various measurements of aircraft weight are important to
airport planning and design, in particular the facilities such as ramps,
taxiways, and runways that are designed to support the aircraft.
While it is rare that any two aircraft, even those of the same model
and configuration, have the same weight measurements (as there are
almost always variations between aircraft in equipment, seating con-
figurations, galleys, and other objects), most manufactures will assign
typical weights to their aircraft for planning and design purposes.
These weights are as follows.
The “lightest” measure of an aircraft’s weight is known as the oper-
ating empty weight (OEW), the basic weight of the aircraft including
crew and all the necessary gear required for flight but not including