carry heavy loads at high speeds for long distances. What was more, the

Such places are kept supplied wholly by air..
5. After World War П, bigger and faster airliners were introduced. 
Jet-propelled aircraft were first used in 1950. Air transport is very valuable 
for emergency medical work. The most important use of air transport 
besides carrying passengers is carrying mail. If the letters are sent by air 
mail, they are not long in coming. Although it is unlikely that aircraft will 
ever replace ships for carrying heavy and bulky cargoes such as oil, coal, 
minerals, grain and machinery, air transport is already proving a serious 
rival to passenger ships on some routes.
6. Helicopters are Hovercraft. 1 Helicopters are very useful in 
places where there is no room for long, flat runways. Madem turbo-jet 
airliners need a run of nearly two m iles lang to take off, but helicopters 
can use small fields, platfarms mounted on ships and the flat tops of 
buildings. Helicopters were first introduced for regular airline service 
1947. Later, helicopters were used for canying passengers and mail on 
short routes, and for taking airline passengers between the centres of cities 
and the main airports.
7. While helicopters gain in needing very little space for taking-off 
and landing, they lose because the speed at which they move forward is 
quite low. So the problem was to develop an aircraft combining the 
advantages of the helicopter with the high speed of an ordinary aircraft. If 
the designers could develop such a machine the problem would besalved. 
So far this purpose the hovercraft was designed. Hov ercrafts are likely to 
be useful for ferry services - for exam ple, in ferrying motor cars across 
the English Channel. They may also be useful for travel in roadless 
countries.

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