Section B In this section, there is 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. Remember to write the
answers on the answer sheet.
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. Birdstrikes 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 bird strike. It usually happens when an aircraft is close (51)
, and may result in significant damage of the aircraft or loss of the
aircraft and (52) 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 (53) Local authorities need to take care
when deciding on (54) 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 (55) in order to bring about changes in
land use.