Super 80 Professional – AOM
WARNING SYSTEMS
Section 24 Page 11
Super 80 Professional – Aircraft Operating Manual
Coolsky, 2018
Protection Envelopes
TCAS provide two envelopes of protection
around the aircraft:
Closure protection (time based protection
envelope).
•
TCAS projects closure rate and future
altitude separation based on
bearing, range and altitude
information from the other altitude
reporting aircraft.
•
A TA is issued if IFR separation will be
compromised and the time of the
closure is less than 45 seconds.
•
An RA is issued when the conflicting
aircraft is less than 35 seconds away
and the conflicting traffic is
determined to be a threat.
Perimeter Protection (distance based
protection envelope)
•
TCAS has two range perimeters. The
outer perimeter varies with altitude
from half a mile at low altitudes, to
one and a half mile at high altitudes.
The inner perimeter is 1200 feet less
than the outer perimeter.
•
A TA is issued when the outer
perimeter is penetrated and altitude
separation is compromised.
•
A RA is issued when the inner
perimeter is penetrated and altitude
separation is compromised.