NORMAL OPERATIONS
TAXI
A318/A319/A320/A321
FLIGHT CREW TRAINING MANUAL
Proper centerline following
If both pilots act on the tiller or pedals, their inputs are added until the maximum value of the steering angle (programmed within the BSCU) is reached.
When the seating position is correct, the cut-off angle is 20 °, and the visual ground geometry provides an obscured segment of 42 ft (12.5 m). During taxi, a turn must be initiated before an obstacle approaches the obscured segment. This provides both wing and tail clearance, with symmetric thrust and no differential braking.
Asymmetric thrust can be used to initiate a tight turn and to keep the aircraft moving during the turn. If nosewheel lateral skidding occurs while turning, reduce taxi speed or increase turn radius. Avoid stopping the aircraft in a turn, because excessive thrust will be required to start the aircraft moving again.
The flight crew should be aware that the main gear on the inside of a turn will always cut the corner and track inside of the nosewheel track. For this reason, the oversteering technique may be considered especially for A321 where main gear is 20 m behind the pilot.
NORMAL OPERATIONS
TAXI
A318/A319/A320/A321
FLIGHT CREW TRAINING MANUAL
Oversteering technique
When exiting a tight turn, the pilot should anticipate the steer out. Additionally, the pilot should allow the aircraft to roll forward for a short distance to minimize the stress on the main gears.
In the event that one or more tires is/are deflated on the main landing gear, the maximum permitted
steering angle will be limited by the aircraft speed. Therefore, with one tire deflated, the aircraft speed is limited to 7 kt and nosewheel steering can be used. With two tires deflated, the aircraft speed is limited to 3 ktand nosewheel steering angle should be limited to 30 °.
For turns of 90 ° or more, the aircraft speed should be less than 10 kt.
180 ° TURN
For turn of 180°, the following procedure is recommended for making a turn in the most efficient way.
For the CM1
? Taxi on the right hand side of the runway and turn left to establish a 25 ° divergence from the runway axis (using the ND or PFD) with a ground speed between 5 kt and 8 kt
? When CM1 assesses to be physically over the runway edge, smoothly initiate a full deflection turn to the right
? Asymmetric thrust will be used during the turn. Anticipation is required to ensure that asymmetric thrust is established before the turn is commenced, between 30 % and 35 % (or 1.02 and 1.03 EPR), to maintain a continuous speed of approximately 5 to 8 kt throughout the manoeuvre
? It is essential to keep minimum ground speed during the turn in order not to need to increase the thrust too significantly so as not to get stuck. It is a good practice that the CM2 calls the GS from ND while in turn
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