This video provides an overview of End-Around Taxiways
by the Office of Airports at the Federal Aviation Administration.
For information on End-Around Taxiways,
refer to Advisory Circular (AC) 150/5300-13, Airport Design,
for specific design standards.
See www.faa.gov.
Images in this video are graphical representations only and are not to scale.
Discussion topics include
Overview,
Aircraft,
Departure and Approach Surfaces,
Visual Screen,
and End-Around-Taxiway Examples.
Overview
To increase operational capacity,
many airports have added multiple parallel runways.
Delays often occur when traffic lands on an outboard runway
and crosses an inboard departure runway.
The forecasted growth
in national airport operations may further increase these delays.
An End-Around Taxiway, or EAT,
allows taxiing aircraft to cross the extended runway centerline
without specific clearance from Air Traffic Control.
This improves the efficiency of airport operations
and provides an alternative to taxiing aircraft across a runway.
A properly designed EAT,
with its associated visual screen,
does not interfere with navigational aids, safety areas,
or runway approach and departure surfaces.
The EAT’s design considers parameters unique to
each airport and each runway.
It is recommended practice to construct the EAT
below the runway end elevation.
This minimizes the necessary distance between
the end of the runway and points along that portion of
the EAT crossing the extended runway centerline.
The aircraft types are important EAT design factors.
Consider these three aircraft dimensions when designing an EAT.
The H sub Eye dimension
is the height of the pilot’s eye above the pavement
for the critical aircraft taking off on the runway.
The H sub Nacelle dimension
is the height of the engine’s nacelle above the pavement
for the critical aircraft on the EAT.
The H sub Tail dimension
is the tail height above the pavement of the critical aircraft on the EAT.
Departure and Approach Surfaces
This plan view shows the relationship of an aircraft on the runway,
an aircraft on the EAT, and the visual screen.
V1 is the aircraft speed at the point which a pilot decides
to abort a takeoff if the aircraft is going to stop on the runway.
The pilot can clearly determine
that the taxiing aircraft is either on the EAT
or crossing the end of the runway.
The visual screen aids in this determination by masking
the departing pilot's view of the taxiing aircraft's engine nacelle.
Using this information,
the pilot decides whether or not to proceed with the takeoff.
This is a cockpit view of an aircraft taking off.
Before the V1 point,
an aircraft enters the field of view from the left.
Upon reaching the V1 point,
the pilot clearly determines that the taxiing aircraft
is not crossing the runway when the visual screen masks
the view of the engine’s nacelle.
With this information,
the pilot establishes that the passing aircraft
is not on the runway,
allowing the pilot to proceed with the take-off.
This is a plan view of an EAT displaying the departure surfaces.
The Airport Design AC
contains guidance on approach and departure surfaces information
for the initial planning and design of an EAT.
Runways with instrument procedures
involve a final review by the Flight Procedures Team
to ensure taxiing aircraft do not conflict with these procedures.
As the aircraft taxis on the EAT,
neither its wings nor tail may penetrate
the approach and departure surfaces.
At a certain distance from the runway,
the aircraft can taxi under these surfaces without conflict.
Consider all elevations of the runway end and the taxiway.
Locate the EAT to ensure that the 40:1 departure surface
is free of penetrations.
With clear EAT approach and departure surfaces,
the airport can simultaneously
conduct taxiing and take-off operations.
A visual screen is an important element for an EAT.
The screen’s size and diagonal red and white stripes
are conspicuous and recognizable to pilots.
Through a partial or complete masking effect,
the visual screen informs pilots on the runway
whether an aircraft is crossing the active runway
or operating on the EAT.
The use of reflective screen material negates
the need for additional nighttime lighting.
A visual screen is not necessary if the airport’s terrain
masks the pilot’s eye-level view of the EAT aircraft’s engine nacelle.
Design EATs for local conditions.
Refer to AC 150/5300-13 for detailed information
regarding equations and calculations for EAT and visual screen design.
In the following three real-world examples,
the EATs may look different,
but their designs use the same criteria
explained in this video and the AC.
The first example is an EAT
at Detroit Metropolitan Wayne County Airport.
This configuration uses a single visual screen.
The second example is an EAT
at Dallas/Fort Worth International Airport.
Because this EAT traverses through two extended
runway centerlines, this configuration uses two visual screens.
The third example is an EAT
at Hartsfield-Jackson Atlanta International Airport.
A visual screen is not necessary for this EAT.
The EAT’s elevation is low enough,
compared to the runway end elevation,
that the airport's ground terrain sufficiently blocks
the pilot's view of the aircraft on the EAT.
These reference materials provide guidance on
End-Around Taxiway design.
Please visit www.faa.gov
to find documents, videos, and other related resources.
The FAA appreciates your interest.
Safe flying.