.
Event resulting from an incorrect flare technique;
.
Events resulting from unanticipated or more-severe-than-expected adverse weather conditions;
.
Events resulting from reduced or loss of lift dumping or braking efficiency;
.
Events resulting from an abnormal configuration, including:
. aircraft dispatch under minimum equipment list [MEL] / dispatch deviation guide [DDG]; or,
. in-flight malfunction; and,
.
Events resulting from incorrect crew action and coordination, under adverse technical or weather conditions.
Corresponding company prevention strategies and individual lines-of-defense can be developed for each family through:
.
Strict adherence to SOPs;
.
Enhanced awareness of environmental factors;
.
Enhanced understanding of aircraft performance and handling techniques; and,
.
Enhanced alertness for:
. flight-parameters monitoring:
. excessive-deviation callouts; and,
. mutual cross-check and back-up.
Preventing Runway Excursions and Overruns
Page 4
Associated Briefing Notes
The following specific Briefing Notes provide expanded information to supplement the above overview:
.
1.1 - Operating Philosophy - SOPs,
.
1.4 - Standard Calls,
.
6.4 - Bouncing Recovery – Rejected Landing,
.
7.1 - Flying Stabilized Approaches,
.
8.2 - The Final Approach Speed,
.
8.3 - Factors Affecting Landing Distances,
.
8.4 - Optimum Use of Braking Devices,
.
8.5 - Operation on Wet or Contaminated Runway,
.
8.6 - About Wind Information,
.
8.7 - Crosswind Landing.
Preventing Runway Excursions and Overruns
Page 5
Introduction
Assuring a safe landing requires achieving a balanced distribution of safety margins between:
.
The computed final approach speed; and,
.
The resulting landing distance.
This Briefing Note provides an overview of:
.
The definition of the final approach speed;
.
Factors affecting the computation of this target speed; and,
.
Rule applied for the combination of speed corrections.
Statistical Data
The assessment of the final approach speed rarely is a factor in approach-and-landing incidents and accidents (even in runway overrun events), but
approaching at a speed significantly faster than the computed target speed often is cited as a causal factor.
Defining the Final Approach Speed
The final approach speed is the speed to be maintained down to 50 ft over the runway threshold.
The final approach speed computation is the result of a tactical choice performed by the flight crew to assure the safest approach and landing for the prevailing conditions in terms of:
.
Gross weight;
.
Wind conditions;
.
Flaps configuration (when several flaps configuration are certified for landing);
.
Aircraft configuration (speed corrections for abnormal configurations);
.
Icing conditions;
.
Use of A/THR in SPD mode; or,
.
Autoland.
The final approach speed V APP can be computed based on the reference threshold speed V REF or on the minimum selectable speed V LS (as available).
V REF is defined as:
V REF = 1.X (*) x (stall speed with full landing flaps* )
V LS is defined as:
V LS = 1.X (*) x (stall speed in actual configuration* )
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