Section D This section consists of one passage
followed by a summary. Read the passage carefully and complete the summary below
by choosing no more than three words from the passage for each blank. Remember
to write the answers on the answer sheet. Questions 61 to 65 are based on the following
passage. Collision between an aircraft and one or more
birds is termed a bird-strike. Pilots sometimes record a birdstrike while at
cruising altitudes, but most of them happen when an aircraft is relatively close
to the ground, usually in proximity to an airport and during the circling,
descent to land or take-off phases of a flight. bird-strikes may
cause significant damage to an aircraft and/or, if the birds are ingested into a
jet engine, a significant and sudden loss of power. If this were to happen
during take-off or initial climb of a fully loaded passenger aircraft the
results could be catastrophic--loss of the aircraft and the lives of those on
board. Any bird is a potential hazard to aircraft and this is especially true as
bird numbers and bird size increase. Unfortunately airports
themselves can be attractive to birds-rodents, insects and other small animals
are a food source often found in flat grassed areas such as the runway strips.
Even so, this problem can be reduced by careful habitat management or bird
harassment techniques practised by airport maintenance and safety
personnel. Further problems may arise because the airport is
located on bird migration routes. These may have existed prior to the airport
site selection--but may not have been taken into account because the problem was
not understood at the time--or have only been recently established because the
birds have found an attractive new food source. Care needs to be taken by local
authorities in deciding the location of rubbish tips, or when permitting other
land uses that may be attractive to birds in this way. Of course these effects
cannot always be anticipated with certainty since birds such as gulls have been
recorded as travelling 50 kilometres or more from their roosting area to an
attractive food source. Agricultural uses may be thought
desirable because they are compatible with high levels of noise exposure, but
they can have an adverse effect on air-craft operations if birds are attracted
during seeding or crop cultivation. Birds may also be attracted to pig farms
where garbage is used as fodder. Even tree plantings can present a hazard if the
species provides an attractive food source or nesting habitat.
Local authority planning schemes often apply strict controls on
developments such as abattoirs, cattle feed lots, grain handling, piggeries,
canals and marina developments, fish farms, and suchlike. In most cases these
uses will not be permitted without a full environmental study. That study should
be required to deal with the question of likely bird hazards if the proposed
location is in proximity to an airport. In some instances it may
be necessary to consider ways of managing a particular land use in order to
reduce its attractiveness to birds, for example the adoption of land-fill
measures at garbage tips, or enclosed rather than open-air activity. Specialist
ornithological opinion may be necessary. In such cases it may not be possible to
implement immediate changes in land use, but this should not inhibit the
adoption of long-term measures which are designed to achieve this. Summary: A collision between an aircraft
and one or more birds is known as a birdstrike. It usually happens when an
aircraft is (61) , and may result in significant damage of
the aircraft or loss of the aircraft and (62) of passengers
and crew if they occur during take-off or initial climb. Because birds can find
plenty food in flat grassed areas, airports are especially attractive to birds.
However, the danger can be minimized by (63) Local
authorities need to take care when deciding on (64) It is
suggested that a full environmental study should be made before making plans of
developments on the land in proximity to an airport. Local authorities should
get advice from specialists and take (65) in order to bring
about changes in land use.