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5.4 – Wind Shear Awareness,
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8.1 - Preventing Runway Excursions and Overruns,
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8.3 - Factors Affecting Landing Distances,
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8.4 - Optimum Use of Braking Devices.
Regulatory References
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FAA AC 120-29 – Criteria For Approval of Category I and Category II Landing Weather Mimima for FAR 121 Operators.
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FAA AC 120-28D – Criteria For Approval of Category III Weather Mimima for Takeoff, Landing and Rollout.
The Final Approach Speed
Page 5
AIRBUS INDUSTRIE Getting to Grips with
Flight Operations Support Approach-and-Landing Accidents Reduction
Introduction
Runway overruns are involved in 12 % of approach-and-landing accidents.
Understanding the factors affecting landing distance can contribute to reducing the number of runway-overrun events.
This Briefing Note is supplemented by the Briefing Notes 8.2 – The Final Approach Speed and
8.4 - Optimum Use of Braking Devices .
Defining the Landing Distance
When referring to the landing distance, two definitions must be considered:
.
The actual landing distance achieved to land and come to a complete stop (on a dry runway) after crossing the runway threshold at 50 ft.
The actual landing distance is used as reference for any in-flight assessment of the landing distance.
.
The required landing distance is obtained by applying a regulatory factor to the actual landing distance.
The required landing distance is used for dispatch purposes (i.e., for selecting the destination, alternate and diversion airports).
Actual landing distances are demonstrated during certification flight tests without the use of thrust reversers.
Figure 1 and Figure 2 illustrate the actual and required landing distances, as defined by the European JAA / U.S. FAA and by the U.K. CAA.
Required Landing Distance - JAA / FAA
Required runway length (dry) = Actual landing distance (dry) x
1.67 Required runway length (wet) = Actual landing distance (dry) x
Figure 1
Required Landing Distance - UK CAA
Dry or Wet runway
Actual landing Regulatory
Distance ( dry )Factor = 1.92
50 ft at threshold
Required runway length (dry or wet) = Actual landing distance (dry) x
1.92
Figure 2
Factors Affecting Landing Distance
Page 1
AIRBUS INDUSTRIE
Flight Operations Support
Factors Affecting Landing Distance
The actual landing distance is affected by various operational factors; thus reducing the regulatory margins, this includes:
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Airfield elevation or low QNH condition (i.e., increased ground speed);
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Runway profile (i.e., downhill slope);
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Runway condition (i.e., nature and depth of contaminant; wet runway or runway contaminated by standing water, slush, snow or ice);
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Wind conditions (e.g., tailwind component);
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Type of braking used (i.e., pedal braking or autobrake, use of thrust reversers);
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Anti-skid failure;
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Incremental addition of all speed corrections on the final approach speed;
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Deviation from the final approach speed;
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Landing techniques (i.e., height and speed at threshold, thrust reduction and flare technique);
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Deviations from SOPs (e.g., failure to arm ground spoilers);
