MECHANICAL BACKUP

Applicable to: ALL
The purpose of the mechanical backup is to achieve all safety objectives
in MMEL dispatch condition:

To manage a temporary and total electrical loss,
the temporary loss of five fly-by-wire computers,
the loss of both elevators,
or the total loss of ailerons and spoilers.
It must be noted that it is very unlikely that
the mechanical backup will be used, due to the
fly-by-wire architecture. For example, in case of
electrical emergency configuration, or an all-engine
flameout, alternate law remains available.
In the unlikely event of such a failure,
mechanical backup enables the PF to safely stabilize the
aircraft, using the rudder and manual pitch trim,
while reconfiguring the systems

In such cases, the objective is not to fly the aircraft accurately,
but to maintain the aircraft attitude safe and stabilized,
in order to allow the restoration of lost systems.
The pitch trim wheel is used to control pitch.
Any action on the pitch trim wheel should be applied
smoothly, because the THS effect is significant due to its large size.
The rudder provides lateral control, and induces
a significant roll with a slight delay.
The PF should apply some rudder to turn, and wait for the aircraft reaction.
To stabilize and level the wings,
anticipate by releasing the rudder pedals.
A red “MAN PITCH TRIM ONLY” message appears on the PFD
to immediately inform the PF that the
mechanical backup is being used.

back-up indication on PFD

ABNORMAL ATTITUDES

Applicable to: ALL

If the aircraft is, for any reason, far outside
the normal flight envelope and reaches an abnormal
attitude, the normal controls are modified
and provide the PF with maximum efficiency in regaining
normal attitudes.
(An example of a typical reason for being far outside the
normal flight envelope would be the avoidance of a mid-air collision).

The so-called "abnormal attitude" law is :

• Pitch alternate with load factor protection (without autotrim)
• Lateral direct law with yaw alternate

These laws trigger, when extreme values are reached:

• Pitch (50 ° up, 30 ° down)
• Bank (125 °)
• AOA (30 °, -10 °)
• Speed (440 kt, 60 kt)
• Mach (0.96, 0.1).

It is very unlikely that the aircraft will reach these attitudes,
because fly-by-wire provides protection to
ensure rapid reaction far in advance.
This will minimize the effect and potential
for such aerodynamic upsets.
The effectiveness of fly-by-wire architecture,
and the existence of control laws, eliminate the need for
upset recovery maneuvers to be trained on protected Airbus aircraft.

SIDESTICK AND TAKEOVER P/B

Applicable to: ALL

When the Pilot Flying (PF) makes an input on the sidestick,
an order (an electrical signal) is sent to the fly-by-wire computer.
If the Pilot Not Flying (PNF) also acts on the stick,
then both signals/orders are added.

Therefore, as on any other aircraft type,
PF and PNF must not act on their sidesticks at the same time.
If the PNF (or Instructor) needs to take over,
the PNF must press the sidestick takeover pushbutton,
and announce: "I have control".
If a flight crewmember falls on a sidestick, or a mechanical failure leads
to a jammed stick (there is no associate ECAM caution),
the "failed" sidestick order is added to the "non failed" sidestick order.

In this case, the other not affected flight crewmember
must press the sidestick takeover pushbutton for at least 40 s,
in order to deactivate the "failed" sidestick.
A pilot can at any time reactivate a deactivated stick
by momentarily pressing the takeover pushbutton on either stick.

In case of a "SIDE STICK FAULT" ECAM warning, due to an electrical failure,
the affected sidestick order (sent to the computer) is forced to zero.
This automatically deactivates the affected sidestick.
This explains why there is no procedure associated with this warning.

AUTOPILOT/FLIGHT DIRECTOR

OBJECTIVE

The Auto Pilot (AP) and Flight Director (FD) assist the flight crew
to fly the aircraft within the normal flight envelope, in order to:

• Optimize performance in the takeoff, go-around, climb, or descent phases
• Follow ATC clearances (lateral or vertical)
• Repeatedly fly and land the aircraft with very high accuracy
in CAT II and CAT III conditions.

To achieve these objectives:

• The AP takes over routine tasks. This gives the Pilot Flying (PF)
the necessary time and resources to assess the overall operational situation.
• The FD provides adequate attitude or flight path orders, and enables the PF
to accurately fly the aircraft manually.

MANAGED AND SELECTED MODES

The choice of mode is a strategic decision that is taken by the PF.

Managed modes require:

• Good FMS navigation accuracy (or GPS PRIMARY)
• An appropriate ACTIVE F-PLN
(i.e. the intended lateral and vertical trajectory is entered, and
the sequencing of the F-PLN is monitored).

MAIN INTERFACES WITH THE AP/FD

*The DIR TO function is an exception to this rule.

OPERATIONAL RECOMMENDATION:

With the FMS, anticipate flight plan updates by preparing:

• EN ROUTE DIVERSIONS
• DIVERSION TO ALTN
• CIRCLING
• LATE CHANGE OF RWY in the SEC F-PLN.

This enables the MCDU to be used for short-term actions.

TASKSHARING AND COMMUNICATIONS

The FCU and MCDU must be used, in accordance with the rules outlined below,
in order to ensure:

• Safe operation (correct entries made)
• Effective inter-pilot communication (knowing each other's intentions)
• Comfortable operations (use "available hands", as appropriate)

AP/FD MONITORING

The FMA indicates the status of the AP, FD, and A/THR,
and their corresponding operating modes.

The PF must monitor the FMA, and announce any FMA changes.

The flight crew uses the FCU or MCDU to give orders to the AP/FD.

The aircraft is expected to fly in accordance with these orders.

The main concern for the flight crew should be:

WHAT IS THE AIRCRAFT EXPECTED TO FLY NOW ?
WHAT IS THE AIRCRAFT EXPECTED TO FLY NEXT ?

If the aircraft does not fly as expected:

‐ Or, disengage the AP, and fly the aircraft manually.

AUTOPILOT (AP) OPERATION

The AP can be engaged within the normal flight envelope,
5 s after liftoff and at least 100 ft.
It automatically disengages, when the aircraft flies
significantly outside the normal flight envelope limits.
The AP cannot be engaged, when the aircraft is outside the flight envelope.
Flight control laws are designed to assist the flight crew to
return within the flight envelope, in accordance with the selected strategy.

The AP may be used:

• For autoland: Down to the aircraft landing rollout,
in accordance with the limitations indicated in the FCOM

• For other approaches, down to:

‐ The MDA for straight in Non Precision Approach
‐ The DA for straight in LNAV/VNAV approach
‐ MDA - 100 ft for circling approach
‐ 160 ft for ILS approach with CAT1 displayed on FMA
‐ 500 ft for all others phases.

It may also be used, in case of:

• Engine failure: Without any restriction,
within the demonstrated limits, including autoland
• Abnormal configuration (e.g. slats/flaps failure):
Down to 500 ft AGL. Extra vigilance is required in these configurations.
The flight crew must be ready to take over, if the aircraft
deviates from its intended, safe flight path.

The sidestick's instinctive disconnect pushbutton should be used to disengage the AP.
Instinctive override action on the sidestick also disengages the AP.
It consists in pushing or pulling the sidestick beyond a given threshold.

The flight crew should use the FCU AP pushbutton when they
perform an AP switching (changeover from AP1(2) to AP2(1)).

RECOMMENDED PRACTICE FOR AUTOPILOT ENGAGEMENT

Before engaging the Autopilot (AP), the Flight Crew should:

‐ Fly the aircraft on the intended path
‐ Check on FMA that Flight Director (FD) is engaged
with the appropriate guidance modes for the intended flight path;
if not, select FD ON, and the appropriate guidance mode(s) as required
‐ Center the FD bars with the aircraft symbol on the PFD

Note:

Engaging the AP while large orders are required to achieve the intended flight path
may result in the AP overshooting the intended vertical and/or lateral target.

This situation may surprise the pilot due to the resulting
large pitch / roll changes and thrust variations.

USE OF THE FD WITHOUT THE AP

When manually flying the aircraft with the FDs on,
the FD bars or the FPD symbol provide lateral and vertical orders,
in accordance with the active modes that the flight crew selects.

Therefore:

‐ Fly with a centered FD or FPD
‐ If not using FD orders, turn off the FD.

It is strongly recommended to turn off both FDs,
to ensure that the A/THR is in SPEED mode, if
the A/THR is active.