曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
These speeds may be used for weights less than or equal to the performance
limited weight.
The FMC will protect for minimum control speeds by increasing V1, VR
and V2 as required. However, the FMC will not compute takeoff speeds
for weights where the required speed increase exceeds the maximum
certified speed increase. This typically occurs at full rated thrust and light
weights. In this case, the message "V SPEEDS UNAVAILABLE" will
appear on the FMC scratchpad and the takeoff speed entries will be blank.
Takeoff is not permitted in this condition as certified limits have been
exceeded. The options are to select a smaller flap setting, select derate
thrust and/or add weight (fuel). Selecting derate thrust is the preferred
method as this will reduce the minimum control speeds. Note that the
assumed temperature method may not help this condition as the minimum
control speeds are determined at the actual temperature and therefore are
not reduced.
Clearway and Stopway V1 Adjustments
Takeoff speed corrections are to be applied to V1 when using takeoff
weights based on the use of clearway and stopway.
Adjust V1 by the amount shown in the table. The adjusted V1 must not
exceed VR. If V1 is greater than VR, VR may be increased to equal V1.
The resultant V2 will be increased by the same amount that VR was
increased.
Maximum allowable clearway limits are provided for guidance when more
precise data is not available.
787 Flight Crew Operations Manual
Performance Inflight
Text
FAA
Category A Brakes
PI.18.2 Boeing Proprietary
VREF Speeds
This table contains flaps 30, 25 and 20 reference speeds for a given weight.
Flap Maneuver Speeds
This table provides the flap speed schedule for recommended maneuver
speeds. Using VREF as the basis for the schedule makes it variable as a
function of weight and will provide adequate maneuver margin above stall
at all weights.
During flap retraction/extension, movement of the flap to the next position
should be initiated when within 20 knots of the recommended speed for
that position.
Slush/Standing Water
Experience has shown that aircraft performance may deteriorate
significantly on runways covered with snow, slush, standing water or ice.
Therefore, reductions in runway/obstacle limited takeoff weight and
revised takeoff speeds are necessary. The tables are intended for guidance
in accordance with advisory material and assume an engine failure at the
critical point during the takeoff.
The entire runway is assumed to be completely covered by a contaminant
of uniform thickness and density. Therefore this information is
conservative when operating under typical colder weather conditions
where patches of slush exist and some degree of sanding is common.
Takeoffs in slush depths greater than 13mm (0.5 inches) are not
recommended because of possible airplane damage as a result of slush
impingement on the airplane structure. The use of assumed temperature
for reduced thrust is not allowed on contaminated runways. Interpolation
for slush/standing water depths between the values shown is permitted.
Takeoff weight is determined as follows:
(1) Determine the dry field/obstacle limit weight for the takeoff flap
setting.
(2) Enter the Weight Adjustment table with the dry field/obstacle limit
weight to obtain the weight reduction for the slush/standing water depth
and airport pressure altitude.
(3) Adjust field length available for temperature by amount shown on
chart.
(4) Enter the V1(MCG) Limit Weight table with the field length and
pressure altitude to obtain the slush/standing water limit weight with
respect to minimum field length required for V1(MCG) speed.
787 Flight Crew Operations Manual
Performance Inflight
Text
FAA
Category A Brakes
Boeing Proprietary PI.18.3
The maximum allowable takeoff weight in slush/standing water is the
lesser of the limit weights found in steps 2 and 4.
Takeoff speed determination:
(1) Determine takeoff speeds V1, VR and V2 for actual brake release
weight using Takeoff Speeds from the Performance Dispatch chapter or
from the FMC.
(2) If V1(MCG) limited, set V1=V1(MCG). If not limited by V1(MCG)
considerations, enter the V1 Adjustment table with actual brake release
weight to determine the V1 reduction to apply to V1 speed. If the adjusted
V1 is less than V1(MCG), set V1=V1(MCG).
Slippery Runway
Airplane braking action is reported as good, medium or poor, depending
on existing runway conditions. If braking action is reported as good,
conditions should not be expected to be as good as on clean, dry runways.
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
787机组操作手册Flight Crew Operations Manual 1(91)
