Minimum Aviation System Performance Standards for Aircraft ...

4.5.2 GIM-S
operations is the provision of precise guidance within the flight deck to enable the flight
crew to actively manage the spacing relative to the Target Aircraft. During IM
Operations, the controller retains responsibility for separation, while the flight crew is
responsible for using the FIM Equipment to achieve and/or maintain the ATC Assigned
Spacing Goal. This does not differ greatly from current operations when controllers
provide speed and turn clearances to manage traffic. With ASPA-FIM, however, the
flight crew has the capabilities and responsibility to actively manage the speed of the
aircraft to meet the operational goals set by the controller. Enabling flight crews to
manage their spacing using the FIM Equipment is expected to reduce controller workload
related to the IM Aircraft by relieving the controller of the need to communicate several
speed and/or vector instructions.
In response to projected increases in air traffic volume and complexity for the National
Airspace System (NAS), applications for Interval Management (IM) are being developed
to enhance interval management, including merging and spacing operations in en route
and terminal areas for the near-term and mid-term timeframes. These applications
include Flight deck-based IM (FIM), in which the flight crew makes use of specialized
avionics that provides speed and turn commands. The utilization of FIM in the NAS
presupposes the existence of appropriate and integrated Ground-based IM (GIM)
capabilities that provides controllers the capabilities to initiate, monitor, and terminate
FIM-S operations as well as manage non FIM equipped flights. During IM operations,
responsibility for separation may reside with the controller (referred to as spacing
applications or GIM/FIM-S) or with the flight crew (referred to as delegated separation
applications or GIM/FIM-DS). Figure 4.5.2 provides an overview of the various
applications that can be part of IM.
Interval Management –
Spacing (IM‐S)
Ground IM‐S
(GIM‐S)
Interval Management
Flight Deck
Based IM‐S
(FIM‐S)
Interval Management –
Delegated Separation (IM‐
DS)
Ground IM‐DS
(GIM‐DS)
Flight Deck Based
IM‐DS (FIM‐DS)
Figure 4.5.2a: Overview of IM Applications
FIM‐DS with Wake
Risk Management
GIM-S applications, either together with the use of FIM-S or by itself, improve aircraft
spacing during departure, arrival, and cruise phase of flight. The GIM-S applications
assist in reducing the effect of airborne congestion, while increasing runway throughput,
and increase the efficiency and capacity of interval management, including merging and
spacing operations. The GIM-S application utilizes Automatic Dependent Surveillance –
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