曝光臺 注意防騙 網曝天貓店富美金盛家居專營店坑蒙拐騙欺詐消費者

reduced initially as much as 60%, since very little weight is on the wheels and
brake application may cause rapid anti-skid modulation.
Normally, speedbrakes are armed to extend automatically. Both pilots should
monitor speedbrake extension after touchdown. In the event auto extension fails,
the speedbrake should be manually extended immediately.
October 31, 2006
777/787 Flight Crew Training Manual
Landing
Copyright © The Boeing Company. See title page for details.
6.30 FCT 777/787 Preliminary (TM)
Pilot awareness of the position of the speedbrake lever during the landing phase is
important in the prevention of over-run. The position of the speedbrakes should be
announced during the landing phase by the PM. This improves the crew’s
situational awareness of the position of the spoilers during landing and builds
good habit patterns which can prevent failure to observe a malfunctioned or
disarmed spoiler system.
Directional Control and Braking during Landing Roll
If the nose wheels are not promptly lowered to the runway, braking and steering
capabilities are significantly degraded and no drag benefit is gained. Rudder
control is effective to approximately 60 knots. Rudder pedal steering is sufficient
for maintaining directional control during the rollout. Do not use the nose wheel
steering tiller until reaching taxi speed. In a crosswind, displace the control wheel
into the wind to maintain wings level which aids directional control. Perform the
landing roll procedure immediately after touchdown. Any delay markedly
increases the stopping distance.
Stopping distance varies with wind conditions and any deviation from
recommended approach speeds.
Factors Affecting Landing Distance
Advisory information for normal and non-normal configuration landing distances
is contained in the PI section of the QRH. Actual stopping distances for a
maximum effort stop are approximately 60% of the dry runway field length
requirement. Factors that affect stopping distance include: height and speed over
the threshold, glide slope angle, landing flare, lowering the nose to the runway, use
of reverse thrust, speedbrakes, wheel brakes and surface conditions of the runway.
Note: Reverse thrust and speedbrake drag are most effective during the high
speed portion of the landing. Deploy the speedbrake lever and activate
reverse thrust with as little time delay as possible.
Note: Speedbrakes fully deployed, in conjunction with maximum reverse thrust
and maximum manual anti-skid braking provides the minimum stopping
distance.
Floating above the runway before touchdown must be avoided because it uses a
large portion of the available runway. The airplane should be landed as near the
normal touchdown point as possible. Deceleration rate on the runway is
approximately three times greater than in the air.
Height of the airplane over the runway threshold also has a significant effect on
total landing distance. For example, on a 3° glide path, passing over the runway
threshold at 100 feet altitude rather than 50 feet could increase the total landing
distance by approximately 950 feet. This is due to the length of runway used up
before the airplane actually touches down.
October 31, 2006
777/787 Flight Crew Training Manual
Landing
Copyright © The Boeing Company. See title page for details.
FCT 777/787 Preliminary (TM) 6.31
Glide path angle also affects total landing distance. As the approach path becomes
flatter, even while maintaining proper height over the end of the runway, total
landing distance is increased.
Slippery Runway Landing Performance
When landing on slippery runways contaminated with ice, snow, slush or standing
water, the reported braking action must be considered. Advisory information for
reported braking actions of good, medium and poor is contained in the PI section
of the QRH. The performance level associated with good is representative of a wet
runway. The performance level associated with poor is representative of a wet ice
covered runway. Also provided in the QRH are stopping distances for the various
autobrake settings and for non-normal configurations. Pilots should use extreme
caution to ensure adequate runway length is available when poor braking action is
reported.
Pilots should keep in mind slippery/contaminated runway advisory information is
based on an assumption of uniform conditions over the entire runway. This means
a uniform depth for slush/standing water for a contaminated runway or a fixed
braking coefficient for a slippery runway. The data cannot cover all possible
slippery/contaminated runway combinations and does not consider factors such as
　
中國航空網 www.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：787機組訓練手冊Flight Crew Training Manual 787(100)