6 Read an article about the giant concrete arrows that have been found in the USA.
Match sentences A–G with gaps 1–5. There are two extra sentences.
Follow the arrow
If you have even been inside the cockpit of a plane, you will have noticed the large number of
instruments on the walls and ceiling around the pilot’s seat. Many of these buttons, dials and
screens are used in navigation. Unlike car drivers, pilots do not have the luxury of signs and
arrows telling them where to go. 1___ So how were pilots able to find their way in the days
before radio and satellite communication?
In the USA, the problem of navigation first arose when the airmail postal service was
introduced in 1911. In the beginning, huge bonfires were lit to show pilots where to land in the
dark. Later, a more practical solution was found: the construction of giant concrete arrows on
the ground. The arrows were 21 m long and painted bright yellow. 2___ The top light turned
around to attract the pilot’s attention, and two others lit up the arrow and flashed a code to
identify its location.
The first of these arrows was laid in 1924, and by 1929, there were around 1,500 of them.
They formed an illuminated path for airmail pilots stretching from New York to San
Francisco. 3___ But by the 1940s, new navigation techniques were being discovered and
soon, the arrows and their towers were no longer needed. They were gradually abandoned
and some of them were removed completely.
However, not all of the arrows have disappeared. In the state of Montana, they are still used
for guiding pilots through the mountains. 4___ Yet either because of their size or due to their
bad condition, the arrows are not easy to find. In many cases, if you want to see one, it is a
question of knowing where to look.
Which is where retired couple Brian and Charlotte Smith can help. The two are devoted fans
of the arrows and spend much of their time hunting them down. So far, they have located
more than a hundred of them. 5___ Their aim is to preserve the memory of these historical
structures and prevent them from being lost forever.
A Once they find an arrow, they map its location, photograph it and upload the details onto their website.
B To enable pilots to see them at night, a steel tower with lights was built in the middle.
C By the following year, the arrows had reached New York.
D The arrows were spaced about 16 km apart and were an important part of the Transcontinental Airway System.
E Instead, they rely on sophisticated GPS systems.
F Many of the planes were flown by former army pilots.
G Some are still visible in the empty areas of other states such as Utah, Wyoming and Indiana.
If you have even been inside the cockpit of a plane, you will have noticed the large number of instruments on the walls and ceiling around the pilot’s seat. Many of these buttons, dials and screens are used in navigation. Unlike car drivers, pilots do not have the luxury of signs and arrows telling them where to go. Instead, they rely on sophisticated GPS systems. So how were pilots able to find their way in the days before radio and satellite communication?
In the USA, the problem of navigation first arose when the airmail postal service was introduced in 1911. In the beginning, huge bonfires were lit to show pilots where to land in the dark. Later, a more practical solution was found: the construction of giant concrete arrows on the ground. The arrows were 21 m long and painted bright yellow. To enable pilots to see them at night, a steel tower with lights was built in the middle. The top light turned around to attract the pilot’s attention, and two others lit up the arrow and flashed a code to identify its location.
The first of these arrows was laid in 1924, and by 1929, there were around 1,500 of them. They formed an illuminated path for airmail pilots stretching from New York to San Francisco. The arrows were spaced about 16 km apart and were an important part of the Transcontinental Airway System. But by the 1940s, new navigation techniques were being discovered and soon, the arrows and their towers were no longer needed. They were gradually abandoned and some of them were removed completely.
However, not all of the arrows have disappeared. In the state of Montana, they are still used for guiding pilots through the mountains. Some are still visible in the empty areas of other states such as Utah, Wyoming and Indiana. Yet either because of their size or due to their bad condition, the arrows are not easy to find. In many cases, if you want to see one, it is a question of knowing where to look.
Which is where retired couple Brian and Charlotte Smith can help. The two are devoted fans of the arrows and spend much of their time hunting them down. So far, they have located more than a hundred of them. Once they find an arrow, they map its location, photograph it and upload the details onto their website. Their aim is to preserve the memory of these historical structures and prevent them from being lost forever.