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
1.2 The number of runways to be provided in each direction
depends on the number of aircraft movements to be
catered to.
2. Clearways and stopways
2.1 The decision to provide a stopway andlor a clearway
as an alternative to an increased length of runway will depend
on the physical characteristics of the area beyond the runway
ANNEX 14 -VOLUME I ATT A-1
Annex 14 -Aerodromes Volume Z
end, and on the operating performance requirements of the
prospective aeroplanes. The runway, stopway and clearway
lengths to be provided are determined by the aeroplane takeoff
performance, but a check should also. be made of the
landing distance required by the aeroplanes using the runway
to ensure that adequate runway length is provided for landing.
The length of a clearway, however, cannot exceed half the
length of take-off run available.
2.2 The aeroplane performance operating limitations
require a length which is enough to ensure that the aeroplane
can, after starting a take-off, either be brought safely to a stop
or complete the take-off safely. For the purpose of discussion
it is supposed that the runway, stopway and clearway lengths
provided at the aerodrome are only just adequate for the
aeroplane requiring the longest take-off and accelerate-stop
distances, taking into account its take-off mass, runway
characteristics and ambient atmospheric conditions. Under
these circumstances there is, for each take-off, a speed, called
the decision speed; below this speed, the take-off must be
abandoned if an engine fails, while above it the take-off must
be completed. A very long take-off run and take-off distance
would be required to complete a take-off when an engine fails
before the decision speed is reached, because of the
insufficient speed and the reduced power available. There
would be no difficulty in stopping in the remaining acceleratestop
distance available provided action is taken immediately.
In these circumstances the correct course of action would be to
abandon the take-off.
2.3 On the other hand, if an engine fails after the decision
speed is reached, the aeroplane will have sufficient speed and
power available to complete the take-off safely in the remaining
take-off distance available. However, because of the high
speed, there would be difficulty in stopping the aeroplane in
the remaining accelerate-stop distance available.
2.4 The decision speed is not a fixed speed for any
aeroplane, but can be selected by the pilot within limits to suit
the accelerate-stop and take-off distance available, aeroplane
take-off mass, runway characteristics, and ambient atmospheric
conditions at the aerodrome. Normally, a higher decision speed
is selected as the accelerate-stop distance available increases.
2.5 A variety of combinations of accelerate-stop distances
required and take-off distances required can be obtained to
accommodate a particular aeroplane, taking into account the
aeroplane take-off mass, runway characteristics, and ambient
atmospheric conditions. Each combination requires its
particular length of take-off run.
2.6 The most familiar case is where the decision speed is
such that the take-off distance required is equal to the
accelerate-stop distance required; this value is known as the
balanced field length. Where stopway and clearway are not
provided, these distances are both equal to the runway length.
However, if landing distance is for the moment ignored,
runway is not essential for the whole of the balanced field
length, as the take-off run required is, of course, less than the
balanced field length. The balanced field length can, therefore,
be provided by a runway supplemented by an equal length of
clearway and stopway, instead of wholly as a runway. If the
runway is used for take-off in both directions, an equal length
of clearway and stopway has to be provided at each runway
end. The saving in runway length is, therefore, bought at the
cost of a greater overall length.
2.7 In case economic considerations preclude the
provision of stopway and, as a result, only runway and
clearway are to be provided, the runway length (neglecting
landing requirements) should be equal to the accelerate-stop
distance required or the take-off run required, whichever is the
greater. The take-off distance available will be the length of
the runway plus the length of clearway.
2.8 The minimum runway length and the maximum stopway
or clearway length to be provided may be determined as
follows, from the data in the aeroplane flight manual for the
aeroplane considered to be critical from the viewpoint of
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
附件14-机场an14_v1_4ed(112)
