TCAS II V7.1 Intro booklet

Table 6. Recommended Phraseology for
Reporting RAs Within U.S. Airspace
Situation
Responding to an
RA
Initial RA report
issued after RA is
completed
Initial RA report
issued after returning
to assigned clearance
Unable to follow a
newly issued
clearance because
of an RA
Controller
acknowledgement of
any TCAS report
Phraseology
“TCAS Climb” or
“TCAS Descend”
“TCAS Climb (or
descent), returning
to [assigned
clearance]”
“TCAS Climb (or
descent) completed,
[assigned clearance]
resumed”
“Unable to comply,
TCAS resolution
advisory”
No specific
phraseology is
defined
The phraseology shown in Table 6 is
suggested and should contain: (1) name of
the ATC facility, (2) aircraft identification
(ID), and (3) that the aircraft is responding
to a TCAS RA. When a flight crew receives
a TCAS RA to either climb or descend from
their assigned altitude, or the RA otherwise
affects their ATC clearance, or their pending
maneuver or maneuver in progress, the crew
should inform ATC when beginning the
excursion from clearance or as soon as
workload allows in the following manner:
“XYZ Center, (Aircraft ID), TCAS
Climb/Descent”.
Following such a communication, the
designated air traffic facility is not required
to provide approved standard separation to
the TCAS maneuvering aircraft until the
TCAS encounter is cleared and standard
ATC separation is achieved. If workload
permits, traffic information may be provided
by the controller in accordance with FAA
Order 7110.65. When the RA is removed,
the flight crew should advise ATC that they
are returning to their previously assigned
clearance or subsequent amended clearance.
When the deviating aircraft has renegotiated
its clearance with ATC, the designated air
traffic facility is expected to resume
providing appropriate separation services in
accordance with FAA Order 7110.65.
Note: Communication is not required if the
pilot is able to satisfy the RA guidance and
maintain the appropriate ATC clearance.
A significant number of unnecessary RAs
are generated when aircraft converge with
high vertical rates. Guidance in the U.S.
Airman’s Information Manual (AIM), and
recently adopted by some international
agencies, direct that the rate of climb or
descent be reduced during the last 1000 feet
of climb or descent.
The AIM, for example says “attempt to
descend or climb at a rate of between 500
and 1,500 fpm until the assigned altitude is
reached” whereas EUROCONTROL
recommends reducing the rate to 1000 fpm.
Modern aircraft auto flight systems produce
higher vertical rates during this phase of
flight in order to achieve maximum fuel
efficiency. Many operators of these systems
are reluctant to direct their crews to interfere
with the auto flight guidance during the last
1000 feet of climb or descent, either because
of reduced fuel efficiency or concern that
the assigned altitude might not be captured.
This policy may be satisfactory for most
climbs and descents, however when an
aircraft is climbing or descending to an
assigned altitude where there is traffic at an
adjacent altitude, an unnecessary RA may be
generated.
While some operators do not address this
issue in their Airplane Flight Manuals
(AFMs) or Training Programs some do
address the issue during Line Operations
Training with the result that some pilots
follow the recommended guidance while
most do not. Operational experience shows
that good results are obtained by allowing
the auto flight system to fly the last 1000
feet of climb or descent, except when there
is known traffic at the adjacent altitude. At
this time the pilot should reduce the vertical
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