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
Part I, Chapter 1 of this manual also describes the relevant provisions contained in Annex 6
concerning oxygen in flight and fitness of flight crew members, as well as limitations of flight time
intended to ensure that fatigue does not endanger the safety of a flight.
Annex 6, Part I, 6.12 describes the relevant provisions concerning radiation indicators to be carried by
ICAO Preliminary Unedited Version — October 2008 II-1-2
aeroplanes intended to be operated above 15 000 m (49 000 ft).
Figure 1.— Flight deck of an Airbus 330 (courtesy – Airbus)
Working environment
The designated medical examiner must be familiar with the design and operation of aircraft cockpits and
air traffic control towers, so as to enable an adequate assessment of licence holders. Aircraft cockpits are
designed in such a way that the flight crew member can function optimally not only under normal but also
under critical conditions such as peak workloads. The main factors to consider in this working
environment are graphically depicted in Figure 1. The major portion of information gathering is by vision;
therefore limitations of human vision with respect to both acuity, the size and shape of the peripheral
visual fields, and colour perception must be considered against the problems of access to visual
information presented from both inside and outside the cockpit.
The position and operation of controls and flight instruments are fundamental. All controls should be
within easy reach of the crew and all instruments should be easy to read. This will permit the pilot to
acquire the information without interference (sensory acquisition) and permit him to operate all the
controls efficiently (effector function).
The air traffic controller’s workload is subject to wide variation. It depends on such factors as the
number of aircraft supervised, the complexity of air traffic routes, individual aircraft speed and relative
aircraft movement comprising fast and slow aircraft, arrivals, departures and en-route traffic.
ICAO Preliminary Unedited Version — October 2008 II-1-3
An example of the working environment of air traffic controllers is shown in Figure 2. It should be
noted that good manual dexterity and neuromuscular co-ordination are required of controllers in the
discharge of their duties. Good visual acuity, both at distance and for reading is required, and the amount
of colour coded information makes good colour perception necessary. Furthermore, air traffic controllers
should be capable of spreading their attention over a number of tasks simultaneously.
Figure 2.— Air Traffic Controllers at their work stations
PHYSICS OF THE ATMOSPHERE
Barometric pressure
The earth is surrounded by a thin layer of gases and vapours in which two forces counteract: the kinetic
energy of the gas molecules leading them away from each other, and the gravitational attraction due to the
mass of the earth. This attraction is inversely proportional to the square of the distance. The action of
these two forces results in a decrease, with increasing altitude, in the density of the atmosphere and
therefore a decrease in the resulting barometric pressure which follows an exponential curve with
increasing altitude. Associated with this pressure event are other phenomena such as a temperature drop
and an increase in the intensity of solar radiation. From a biological viewpoint, the barometric pressure
drop is the most specific feature of the altitude climate. The manifestations directly related to reduced
barometric pressure per se are of two types:
a) mechanical (expansion of trapped gases); and
ICAO Preliminary Unedited Version — October 2008 II-1-4
0.2094 2
= × O B P P
( 47) 0.2094 2
= − × O B P P
b) biological (drop in oxygen partial pressure).
The chemical composition of the atmosphere remains constant up to an altitude of about 25 km
(82 000 ft). The oxygen fraction is about 20.94 per cent and the partial pressure (pO2) changes in direct
proportion to the total barometric pressure (PB) and can be calculated for dry gas as follows:
(1)
On entering the airways, the inspired gas becomes immediately saturated with water vapour at body
temperature. The partial pressure exerted by the water vapour at 37°C (98.6°F) is always 47 mm Hg
regardless of the total barometric pressure. This fact poses a special problem in aviation medicine because
it is obvious that with increasing altitude, the water vapour pressure represents an increasing proportion of
the inhaled gaseous constituents of the atmosphere. When considering the water vapour pressure, formula
(1) has to be modified as follows:
(2)
Since aviation operations are carried out in an environment different from the regular habitat of
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
Manual of Civil Aviation Medicine 1(57)
