Table 1
AP – A/THR Modes Integration
Design Objective
The design objective of the automatic flight system (AFS) is to provide assistance to the crew throughout the flight (within the normal flight envelope), by:
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Relieving the PF from routine handling tasks and thus allowing time and resources to enhance his/her situational awareness or for problem solving tasks; and,

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Providing the PF with adequate attitude and flight path guidance through the FD, for hand flying.

The AFS provides guidance to capture and maintain the selected targets and the defined flight path, in accordance with the modes engaged and the targets set by the flight crew on the FCU or on the FMS CDU.
The FCU constitutes the main interface between the pilot and the autoflight system for short-term guidance (i.e., for immediate guidance).
The FMS multi-purpose control and display unit (MCDU) constitutes the main interface between the pilot and the autoflight system for long-term guidance (i.e., for the current and subsequent flight phases).
On aircraft equipped with an FMS featuring both lateral and vertical navigation, two types of guidance (modes and associated targets) are available:
.  Selected guidance:
.  the aircraft is guided to acquire and maintain the targets set by the crew on the FCU, using the modes engaged on the FCU.
.  FMS (managed) guidance:
.  the aircraft is guided along the FMS lateral and vertical flight plan, speed profile and altitude targets, as managed by the FMS (accounting for altitude and speed constraints, as applicable).
Understanding Automated Systems
Understanding any automated system, but particularly the AFS and FMS, ideally would require answering the following fundamental questions:
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How is the system designed ?

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Why is the system designed this way ?

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How does the system interface and communicate with the pilot ?

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How to operate the system in normal and abnormal situations ?

The following aspects should be fully understood for an optimum use of automation:

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Integration of AP/FD and A/THR modes (i.e., pairing of modes);

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Mode transition and reversion sequences;

Optimum Use of Automation
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.  Pilot-system interfaces for:
.  Pilot-to-system communication (i.e., for modes engagement and target selections); and,
.  System-to-pilot feedback (i.e., for modes and targets cross-check).
In the context of this Briefing Note, the interface and communication between the flight crew and the system need to be emphasised.
Flight Crew / System Interface
When performing an action on the FCU or FMS CDU to give a command to the AFS, the pilot has an expectation of the aircraft reaction and, therefore, must have in mind the following questions:
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What do I want the aircraft to fly now ?