Look through the text and pick out the items of a weather report.

Weather and Air Traffic Control Accurate weather forecasts are essential to aviation. A pilot before taking off obtains a weather forecast giving him the weather conditions which are expected along the route of the flight and at the destination. As weather conditions affect aircraft in flight, meteorologists provide pilots and air traffic controllers with special aviation forecasts. The basic weather report follows a standard format. First comes the wind speed and direction, usually in knots or meters per second, then the visibility in meters when less than 5 000m and in kilometers when 5000m or greater.	The next item is the weather, for example, rain, fog, mist, haze, snow, etc. Cloud base is measured by means of a cloud base recorder which scans the sky overhead with a laser. Pilots’ reports can be requested to confirm the base. Cloud amount is measured in oktas but it is passed to a pilot like this: sky clear, 1-2 oktas as few, 3-4 oktas as scattered, 5-7 oktas as broken, and 8 oktas as overcast. A major weather problem is thunderstorm, which presents a variety of hazards to aircraft. Aircraft will avoid thunderstorms that can cause delays as routes are closed due to thunderstorms. This information is passed as a forth group.
Air temperature is given in degrees Celsius. The dew point is also important because if the two figures are close together fog may soon form. As for QFE and QNH, they are passed in hectopascals. Where the weather conditions meet particular criteria – visibility of 10 km or more, no precipitation, no thunderstorm or shallow fog, no cloud below a level of 1 500 m and no CB at any level – the word “CAVOK” is passed. In foggy conditions Runway Visual Range, or RVR is passed. It means how far the pilot is likely to be able to see along the RW. Measurement only begins when the meteorological report gives a general visibility of 1 500 m or less, and the pilot decides whether or not it is within the limits known as “company minima”(a pilot’s minima of a certain airline company) for landing or take-off. RVR is measured at touchdown, mid-point and stop end by the human observer method or by means of electronic equipment.	Windshear presents a serious danger as it is invisible and it might cause the aircraft to stall or undershoot the RW. The information about wind shear is included in the ATIS broadcast. Another major hazard to aircraft is easier to measure. This is poor braking action. When the RW is icy, or if there is snow or slush on the RW. Pilots usually report any unexpected weather phenomena which they encounter, severe turbulence or icing, any condition they think may affect the safety of flight. At many busy airports the current weather is transmitted on the terminal VOR frequency. This service is known as ATIS. As well as the weather report it may include useful information such as a type of approach, any holding delays, etc. Each ATIS broadcast has an identifying letter which a pilot must report to an air traffic controller on first contact.

 

 

7. Read the text again, look through the following statements and say if they are true or false:

1.In the basic weather report the wind speed and direction come first. 2.The visibility is always given in kilometers. 3.QFE and QNH are passed in millimeters. 4.When weather conditions are perfect for flight the word “CAVOK” is passed.   5. RVR is measured only at touchdown by means of electronic equipment.   6.The information about wind shear isn’t included in the ATIS broadcast. 7.The higher is the figure of the braking action, the better is the braking action.   8.ATIS includes only information about current weather.

8. Elicit the information from the text given above and answer the following questions. You can use your own experience. 1) Why is accurate weather forecast important for safe flying? 2) Where can a pilot get information about weather conditions? 3) What weather conditions are dangerous for flight? Why?

4) What are perfect flying conditions? 5) What information about RW condition is necessary for a pilot? 6) What unexpected phenomena can a pilot encounter in flights? 7) Is ATIS information available only in one language? 8) What information does an ATIS message include? 9) Who provides a pilot with weather information if ATIS is not available?

Listening and Speaking Bank.

Unit 5A. Exercise 9-10.

Read the instructions and do the task.

VIDEO # 21

Warm up. ¸ Watch a video and guess what we are going to discuss now.

 

1. Look through the text and answer the following question:

Q Why are wind speed and direction very important for flight?

 

WIND IN AVIATION A pilot needs to know wind direction and speed as wind might affect flight negatively. En route the headwind may delay the arrival of flights and is to be avoided if possible. The tailwind can be of a great advantage as it increases the ground speed and results in reduction of fuel consumption. As for the cross wind it is extremely dangerous for an aircraft, especially on landing. An aircraft loses speed and might not get on the RW. What is more, it can cause a crash of the aircraft. Winds vary with altitude and also from one place to another, so information about wind is very important.

2. Read the text and answer the following questions. You can use your own experience.   a) What types of wind do you know in aviation? b) Is cross wind dangerous for take off/landing and at flight level? c) What is cross the wind speed limit for safe flying? d) Is tail wind good for all stages of flight? Why? Why not? e) How can head wind affect flying? f) Do you know any real situation when wind caused an incident or an accident?

 

 

3. Look at the table and check if you are right.

 

	Take off	Landing	At flight level
Cross wind (12-15 mps)	An aircraft loses speed, can drift and cannot get on the RW; lifting power reduces and it might cause crash of the aircraft.	It can cause a deviation from the route.
Tail wind (more than 5 mps)	It is very dangerous; ground speed increases and the length of the RW might be not enough; (it depends on the RW length) the aircraft might roll off the RW.	It is good because speed increases, the aircraft saves fuel and it can get the destination quicker.
Head wind (25 – 30 mps)	It is good because at landing ground speed reduces and the aircraft can stop quicker. At taking off lifting power increases and the aircraft can take off quicker.	It is not good; fuel consumption increases because the aircraft has to resist the wind. The aircraft might be low on fuel.

4. Look through the text and find the definition of windshear. _________________________________ _________________________________ _________________________________ _________________________________ _________________________________
WINDSHEAR Windshear is a sudden and unexpected change in wind speed and direction. Windshear itself is a meteorological phenomenon occurring over a very small distance, but it can be associated with line squalls and cold fronts.	Windshear influences greatly aircraft take-offs and landings due to its effects on steering of the aircraft. Low level windshear can affect aircraft airspeed during take off and landing in dangerous ways.

 

What is more, the additional hazard of turbulence is often associated with windshear. Windshear is also a danger for an aircraft making steep turns near the ground. The different airspeed experienced by each wing tip can result in an aerodynamic stall on one wing, causing a loss of control. As the result of the accidents in the 1970s and 1980s, in 1988 the U.S. Federal Aviation Administration mandated that all commercial aircraft had to be equipped with on-board windshear detection systems. Since 1995, the number of major civil aircraft accidents caused by windshear has dropped to approximately one every ten years.

5. Read the text again and answer the following questions. You can use your own experience. 1. To what extent is windshear dangerous for aviation? 2. At what stages of flight does windshear affect an aircraft most? 3. What are possible results of windshear? 4. What measures are taken to reduce windshear influence in aviation?   6. Round-table talk. 1. How often do pilots report about windshear at your airport? 2. Where can a pilot obtain information about windshear? 3. Is there any special equipment to forecast windshear at your airport? 4. Do you think people will be able to reduce windshear influence on the flight in the future? 5. Speak about any real situation when windshear caused a serious aviation event.

 

VIDEO # 22

Warm up. ¸ Watch a video and guess what we are going to discuss now.

1. Read the text and answer the following questions. You can use your own experience. 1. Why is information about visibility important for flights? 2. How does visibility affect flights? 3. What weather phenomena influence visibility? 4. Under what weather conditions is landing prohibited?

Visibility is often reduced by air pollution and high humidity. Various weather stations report these phenomena as haze or mist. Fog and smoke can reduce visibility to near zero, making flights extremely dangerous. Heavy rain causes not only low visibility, but the inability to brake quickly. The international definition of fog is visibility of less than 1 km; mist is visibility of between 1 and 2 km and haze from 2 to 5 km. Visibility of less than 100 meters or ^1/16^th of a mile is usually reported as zero. Under these conditions, airports might be closed. If visibility or ceiling is below minima a controller doesn’t clear a pilot to descend from transition level and gives instructions to go around. A captain sometimes decides to divert to the alternate.

VISIBILITY In meteorology, visibility is the distance at which an object or light can be clearly seen. It is important for all forms of traffic, especially for aviation.

Listening and Speaking Bank. Unit 5C. Exercise 2-3. Read the instructions and do the task.

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