How do weather conditions affect aircraft endurance

PrivateFly Blog

With record-breaking high temperatures across much of Europe this week, the weather is on the minds of our Jet Card and private jetВ charter clients, many of whom are travelling more frequently over the summer period.

But how do changes in the weather impact flight operations?

Whatever the weather, our expert team is available to discuss your travel plans and our Jet Card and premium charter solutions. ContactВ us or call +44 (0)20 7100 6960.

ConsiderationВ and constant monitoringВ of the day-to-day weather situation forms a key part of handling any flight. Our Client Services team works closely with the aircraft operators and crew when organising your flight,В adjustingВ the route and calculating the timings using a number of weatherВ planning tools and systems.

Different weather conditions impact your flight in different ways – from the everyday consideration of wind strength and direction, to the more unusual challenges of extreme heat, heavy fog or ice and snow. Here’s how.

Aircraft can operate perfectly safely in hot and sunny weather, in very highВ temperatures (up to 53C, depending on the aircraft type). But a high air temperature does change the performance of the aircraft.

Hot air is thinner than cooler air. And this affects the output of the aircraft’s engines as well as aerodynamic capabilities, increasing the required runway distance and reducing climb performance and the maximum payload. Pilots can opt to use a higher engine thrust setting when it’s particularly hot.

So while it’s rarely hot enough for flights to be grounded, it’s something that needs to be factored into the flight plan.

Of course, however hot (or cold) it may be outside, the cabin temperature of a private jet is always set to the passengers’ preference.

Ice & snow

So when it comes to factoring inВ ice or snow, the major focus is the condition of the runway and taxiway at the airport. And on de-icing the aircraft prior to the flight.

De-icing is a legal and safety requirement, for all private jet flights. And de-icing costs can add to the cost of a charter flight – so this is something we always discuss with clients before a flight during colder weather. Find out more about de-icing a private jet.

Private jets are less impacted than airline flightsВ by heavy snowfallВ as they can use smaller airports, where snow clearing andВ de-icingВ can oftenВ take placeВ quicker that at major hubs. There is a much smaller area of taxiway and fewer aircraft to keep clear (plus many private jets are kept out of the cold in hangars which reduces de-icing requirements).

And if all flights are grounded due to extreme snow, theВ agility of private charter means flights can return to normal immediately after restrictions are lifted. Whereas airline schedules often take days to recover.

All aircraft, including private jets, are affected by fog and poor visibility, which can cause flight delays. Although many commercial aircraft are equipped with auto-land autopilots (that can land the aircraft in zero visibility), it is on the ground and during the take off phase that most of the air traffic delaysВ occur.

When the visibility at an airport drops below 1,500m (described by pilots and airports as RVR – Runway Visual Range) the airport enforces Low Visibility Procedures (LVPs). During LVPs, Air Traffic will reduce the number of aircraft taxing and taking off to prevent accidents and incidents occurring.

Fog is often patchy and variable – with some airports affected while others remain clear. so just as with snow, a private jet flight allows for last minute changes of plan during foggy weather, finding gaps in the fog and re-routing the flight accordingly – not an option open to airlines.

For a morning flight, our team can also arrange for aircraft to position in for your flight departure the night before, which can help to avoid delays.

Wind direction and speed can make a flight time quite different, for exactly the same journey. A tail wind – which pushes the aircraft forward through the air – will increase the aircraft’s ground speed and shorten the journey.

A head wind – where the aircraft is flying against the wind direction – obviously does the opposite, slowing the aircraft’s ground speed and making the journey time longer.

These time differences are most dramatically seen on transatlantic flights, due to jet streams. Jet streams are strong westerly winds that blow in a narrow band in the Earth’s upper atmosphere – at the altitudes used by most aircraft. Where these packets of fast moving air form a tube, they are called jet streams.

Aircraft are built and tested to withstand strong winds, but strong winds can be a factor in a turbulent journey. While turbulence can be a worry, it isn’t a safety concern. Read more: What is turbulence?

For take-off and landing, aircraft always moveВ into the wind to reduce the ground speed.

Cross winds can also make take off and landing more challenging. So airports will impose limits if the wind is moving across the runway. Many airports have runways facing in different directions to mitigate against cross winds, allowing the pilots to use the runway that faces into the wind.

Rain doesn’t affect a flight that much in itself. Obviously if combined with very heavy winds, it can cause extra considerations and challenges to flight planning – even a change of route or a delay if the conditions are extreme. But generally speaking, aircraft are very well-equipped to deal with a bit of the wet stuff!

Visibility is the key consideration of course. While at higher cruising speeds, the airflow clears water from the windshield quite effectively (instruments can ‘see’ ahead regardless of the weather) the pilot needs a clear visual view at slower speeds, when coming into land or taxiing on the ground.

So someВ private jets do have windscreen wipers. Others (particularly smaller aircraft) have a high pressure air system, which blows rain offВ the windshield. And some manufacturers, including Gulfstream, useВ hydrophobic windshield coatings, which repel water, in place of wipers.

Thunderstorms

Thunderstorm clouds or Cumulonimbus, are always known as CBs by pilots (this is how they are abbreviated in pilot weather reports and the nickname has stuck).

CBs can be a factor in both hot and wet weather and often followВ periods of very high temperatures.

Private jets are well-equipped to deal with CBs. On departure theyВ have faster climb rates and the ability to get above the weather, leaving airliners behind and below. Then during the flight, less commercial and time pressure than airline pilots means the crew can take longer routes to fly around CBs.

On landing, the agility and manouverability of a private aircraft allows a more flexible approach to the runway, avoiding bad weather on the approach path. They can also descend later and faster to keep out of the bad weather for most of your journey.

However no pilot of any aircraft will fly into a CB, so with safetyВ always theВ number one priority, your flightВ mayВ be delayed by CBs directly overhead your departure airfield. Refuelling of an aircraft is also forbidden with CBs in the vicinity, due to the risk of lightening strikes.

Whatever the weather, our expert team is available to discuss your travel plans and our Jet Card and premium charter solutions. ContactВ us or call +44 (0)20 7100 6960.

Azernews.Az

How bad weather can affect aircraft, and what can be done: Q&A

As search and rescue crews start retrieving wreckage and bodies from AirAsia Bhd. flight QZ8501 in the Java Sea, the role of weather will be among the dozens of factors investigators study to determine what led to the crash of the Airbus Group NV A320 single-aisle jet.

The following questions and answers address some of the issues related to weather and aviation.

*Do we know what role weather played in AirAsia Flight QZ8501?

Investigators have not yet been able to say what role weather played in QZ8501. The pilot had asked to change the route due to weather, a normal procedure when an aircraft’s flight may put it on a path to face heavy weather including turbulence or thunderstorms.

*How can weather affect aircraft?

Wind, more than rain, directly affects how an aircraft flies because lift is created by the movement of air over the wings. Shifts in air pressure, wind speed or direction can impact how much lift is created with sudden changes being capable of forcing an aircraft to rise or fall suddenly.

*How does altitude affect flight performance and safety?

Higher altitudes bring multiple challenges, including thinner air and lower temperatures, which can reduce an aircraft’s performance.

At higher altitudes aircraft engines are less efficient due to the decreased density of the air, while lift created over the wings is also lower.

Higher altitudes can also increase the possibility of ice formation either on the wings, which can limit the aircraft’s ability to produce lift, or on sensors which track airspeed and altitude. Higher altitude air is also harder to breathe, which is why aircraft are pressurized.

While thunderstorms do cause lightning, serious accidents due to lightning strikes are extremely rare.

*What kind of weather can cause problems for aircraft?

Modern commercial jets are able to handle a large range of weather conditions. Thunderstorms and tall clouds called cumulonimbus are among the most risky weather patterns that pilots may face. They can stretch as high as 60,000 feet, well above the ceiling altitude of most commercial aircraft.

Thunderstorms can form quickly, reaching their peak strength within 15 minutes, and usually occur as air warms up creating rising air currents that become extremely turbulent. After reaching maturity, a thunderstorm will start shedding the moisture it absorbed, forming rain or hail and strong downdrafts.

An aircraft entering a thunderstorm could experience updrafts or downdrafts exceeding 3,000 feet per minute. Changes in air pressure and temperature inside a thunderstorm can also lead to icing.

*What technologies are available to track or avoid bad weather?

Satellites, weather balloons and ground radar have been used to both forecast future weather and update current conditions for decades. Ground-based weather radars transmit a signal, then detect and analyze the returning echo to assess the size and concentration of water droplets as well as wind speed.

Because weather patterns can form and dissipate quickly, and weather analysis can be difficult at longer distances, aircraft are being increasingly equipped with on-board systems called Airborne Weather Avoidance Radar.

While AWAR is useful for a pilot to get nearby weather information, it is also limited in both the direction and range at which it can detect wind or rain.

In addition to weather detection and avoidance technology, communications systems are a key tool for pilots to receive and share information.

Aircraft Communications Addressing and Reporting System, or ACARS, is a data-based system that avoids the need for information to be relayed by voice. In addition to aircraft data such as fuel and location, ACARS can be equipped to include weather data.

*Can good equipment allow a pilot to fly through thunderstorms?

On-board AWAR systems are designed to allow pilots to avoid severe weather, not fly through it. The U.S. FAA recommends pilots avoid heavy weather by at least 20 miles.

“Weather recognizable as a thunderstorm should be considered hazardous, as penetration of any thunderstorm can lead to an aircraft accident and fatalities to those on board,” the FAA advises.

Weather Conditions and Aviation: Fog

Of the many variables which can affect trip planning, one of the most crucial is the meteorological outlook. Constantly fluctuating weather conditions can impact route planning, disrupt schedules, and in extreme cases may even prevent a flight from taking place at all. Fog is one such weather feature. Here we will look at fog and aviation, focusing on the different types of fog and their potential impact on flight operations.

What is Fog?

Fog consists of visible water droplets or ice crystals suspended in the air, close to the Earth’s surface. It can be considered a type of low-lying cloud, which occurs when the temperature becomes close to the dew point (the temperature to which air must be cooled to become saturated with water vapor). Fog forms when the dew point rises until it equals the temperature, or the temperature lowers to the same as the dew point.

Both fog and mist have a significant impact on visibility, which in turn can affect aviation operations. Mist is less dense, consisting of smaller water particles which do not fall earthward. It is encoded as BR on Meteorological Terminal Air Reports (METAR) and Terminal Aerodrome Forecast (TAF) reports for visibility levels of 5/8 mile or greater.

Aircraft landing at Vágar Airport, Faroe Islands. Coastal areas tend to be affected by advection fog.

Different Types of Fog

Radiation fog is caused by cooling of the earth’s surface, and can have a big impact on aviation operations. This type occurs only at night, and over land. In most cases, the fog will be thickest at night and dissipates through the morning. It may start to form again soon after sunset. Radiation fog is frequently found throughout Europe during winter, when the nights are longer and the temperature drops.

Advection fog develops in one region, and is then carried by wind currents to a different location. This type usually occurs along coastlines. Advection fog can last for days, and therefore can affect aviation operations more than radiation fog. Advection fog mainly affects airfields located near the sea, and occurs during spring when temperatures fluctuate rapidly. Hotspots for this type include the east coast of America, the Canadian Maritimes, the northeast coast of Russia, and Japan.

Upslope fog occurs due to the cooling of rising air. This generally happens when warm moist air is forced up a slope by the wind. Upslope fog often affects mountainous areas, such as the Rocky Mountains in Colorado.

Frontal fog appears in conjunction with the frontal surface of a colder air mass, due to the evaporation of falling rain. Stationary warm frontal fog has the biggest impact on aviation operations, as it can happen in any part of the world when the required weather conditions are present.

Predicting fog

Fog conditions tend to be transient, and can have rapid variations in density. Forecasters are usually able to predict the potential for fog based on the prevailing meteorological conditions. It can be more challenging, however, to accurately predict the impact on visibility.

A number of resources are available to flight crew to indicate current and predicted fog conditions. It is important for crews to have an understanding of how to read the information portrayed on charts and weather briefs. This helps when it comes to planning for how to deal with a fog event taking place on your route.

Impact of Fog

Weather conditions can potentially delay a flight or to cause it to be diverted from the planned destination airport. Fog has the ability to limit surface visibility to less than 5/8th mile, which can have a significant impact on operations. This often reduces aircraft arrival/departure flow rates, and in extreme cases can even cause the temporary closure of an airfield.

The image above shows thick fog obscuring visibility at London’s Stanstead Airport. Under these conditions, take-offs may have to be delayed.

If fog is causing disruption, crews may need to consider landing at an alternative airport. It is therefore important to carry additional fuel, in case of diversions or delays to scheduled landing times. Rapid reductions in visibility can necessitate a switch from Visual Flight Rules (VFR) to Instrument Flight Rules (IFR) within minutes. These quick changes mostly occur with advection types of fog (along coastlines or in upslope conditions). Radiation fog tends to form more gradually, as temperature lowers towards the dew point over time.

Fog presents both safety and cost issues for operators. Statistics for general aviation accidents in the United States from 1982 to 2013 indicate fog was associated with 40% of all fatalities within the ceiling, visibility, or precipitation-related category (source).

Diversions

Air Traffic Control (ATC) services may require crew to include designated alternate destinations on dispatch releases. This applies if the observed (or forecast) ceilings and visibility at the destination airport are less than 600 meters and/or 4,800 meters, within one hour of the estimated time of arrival. If it is determined that a diversion is necessary, aircrews must select an airport that meets alternate minima requirements. Aerodrome Operating Minima (AOM) are criteria used by pilots to determine whether they may land or take off from any runway. AOM consist of two parts: one relating to the cloud base, and one relating to the visibility and/or Runway Visual Range (RVR). These are usually 120 meters and 1,600 meters, or 180 meters and 3,200 meters. Some smaller airports may require more stringent minima, up to 300 meters and 4,800 meters. Regulations specify that additional fuel must be carried to fly to not only the destination airport, but also to fly to and land at the most distant alternate airport. These requirements can add considerable costs and time to a trip.

Often, the aircraft is already on its approach to an airfield when the decision may be taken to divert. It is important to have suitable alternatives arranged prior to attempting to land. Fog depth and thickness can be transient and vary a great deal from moment to moment. Good weather briefs and preliminary weather reports obtained prior to take-off are excellent sources of information to help anticipate fog events. If poor visibility persists, operators may have to consider adjusting schedules according to the fog situation.

Weather Briefs and Charts

Fog forecasts can be found in the TAF section of a typical weather brief, and are also noted in weather depictions and surface forecast charts. The Runway Visual Range (RVR) section of METARs should be checked for the latest reported runway visibility and weather conditions.

Crews should also refer to general forecasts and Airmen’s Meteorological Information (AIRMETs), issued by the National Weather Service. Weather depiction charts are an excellent reference for areas of fog and stratus. Shaded regions on the chart indicate areas where Instrument Flight Rules (IFR) will be necessary. Surface charts can also be checked for indications of fog or low cloud.

Aviation weather charts should be consulted by crew for the latest meteorological information.

Satellite Imagery

Satellite imagery can be used to help forecast potential fog formations, or to check for areas where persistent fog is prevalent. The 3.9/10.7 micrometer channel is employed at night to depict presence of fog or low level stratus. During daytime, visual satellite imagery is the preferred tool for depicting areas of fog/low clouds. Rough estimates of the depth and extent of fog can be determined by Infra-Red (IR) channel differences, however surface and sounding reports remain more accurate indicators of actual fog depth. In cases where correlating surface reports are not available, IR imagery can be an effective alternative.

Other Sources of Information on Weather Conditions

The NOAA Aviation Weather Center website is a valuable resource for pilots and includes detailed information on worldwide fog and stratus development, as well as other weather conditions.

Still Have Questions About Fog? Consult Our Expert Team!

Climatic conditions are one of the most crucial and unpredictable aspects of flight planning. Jetex recognizes the importance of keeping you updated on any unexpected changes. We provide accurate, up-to-the-minute weather information, ensuring a smooth and safe flight for you and your crew.

Our dedicated trip planning team are experts in their field, and together share a wealth of experience. We have established state-of-the-art operations centers in Dubai, Miami and Beijing. All are fully staffed around the clock, and ready to cater to your needs in any area of the globe.

The Impact Of Weather On Aviation And The Most Frequently Asked Questions About Bad Weather And Air Travel

Whether you are a frequent flyer or occasionally take a flight to a given destination, the chances are good that you experienced a few unsettling moments during one of those flights.

With the weather getting more volatile and extreme by the year, it’s time to take a serious look at the impact these meteorological conditions will have on aviation.

In this post, we examine the effect increasingly inclement weather events have on air transport, and also look at some of the most frequently asked questions about bad weather and the problems it creates in air travel.

Impact of Weather On Aviation

Even in the best weather conditions, airplanes may still experience some «inconveniences» during a flight. Turbulence, crosswinds, and air pocket are just a few normal atmospheric conditions that most passengers consider as part of a routine flight.

You can imagine how increasingly inclement weather can severely impact not just an aircraft’s ability to fly but also to take off in the first place.

What is important to remember is that all forms of extreme weather can have a significant influence on flights. One usually tends to associate cold and stormy weather with canceled or delayed flights.

Although they may be the biggest culprits, they are not the only factors that may cause substantial delays in planned flights. Heatwaves, heavy rain showers, gale-force winds, and low visibility (fog) can all lead to major disruptions at airports and in the air.

Especially with weather conditions getting more extreme on an increasing basis, these events are forcing airports, air traffic controllers, and aircraft manufacturers to take action. Some of them include:

These are just a few of many measures already considered or implemented in the aviation industry throughout the world.

The best way to understand the different inclement weather conditions that have a significant impact on all aspects of weather is to address the questions most frequently asked about bad weather and air travel.

Frequently Asked Questions About Bad Weather And Air Travel

To help you better understand the weather conditions that will impact your air travel, including flight delays, cancellations, and flying conditions, is to answer the most frequently asked questions about inclement weather and aviation:

Can Planes Fly In Thunderstorms?

Apart from snow or icy weather, this is the type of weather that concerns passengers the most. And not without merit. The strong winds, hail, and downdrafts can severely damage or destroy a plane.

Sometimes the cloud system exceeds 35 000 feet (10 670 meters), which is higher than the cruising altitude of an airliner. They can also be up to 12 miles (19.3 kilometers) wide. This makes it difficult for an aircraft to fly over or around in some cases.

It does not mean planes cannot fly during thunderstorms. But pilots try and avoid flying through it at all costs. Today’s accurate weather forecasts allow airlines to plan ahead and create flight plans to avoid thunderstorms.

Even if a thunderstorm develops unexpectedly, the radars in modern airplanes cannot only detect heavy clouds ahead but «see» inside the clouds to determine their density. It allows pilots to decide whether to reroute their planes or carry on through a storm system.

Luckily, the design of more robust and durable aircraft, combined with accurate weather forecasts and advanced radar systems, resulted in no fatal crashes in recent times.

The bottom line is that aircraft can fly in thunderstorms but prefer to reroute and fly around them. Only as a last resort will pilots fly through one, and the design of modern aircraft allows them to withstand the majority of light to mild thunderstorms.

Can Airplanes Fly In Rain?

In the vast majority of cases, the answer is yes. Rain can look much worse than it is, and modern airports and aircraft are more than able to withstand a substantial amount of rain.

There are exceptions and a few dangers, though. One of the side-effects of heavy rainfall is reduced visibility. In extreme cases, pilots may have to abort the takeoff during showers until visibility is restored to a safe level.

On rare occasions, if an aircraft flies through a heavy shower, an engine flameout can occur (where the flame in the engine’s combustion chamber is extinguished, causing it to stop). In basically every instance, though, a pilot can restart the engine if such an event occurs.

Freezing rain occurs in the upper troposphere, where water droplets below freezing point freeze on contact with objects. It can freeze on an aircraft’s wings which may cause a plane to stall on rare occasions. In practically every instance, the pilot is able to regain control.

Can Planes Fly In Extreme Cold Weather?

The answer is a definite yes. Cold conditions actually favor the performance of aircraft. Cold air has a high density, which allows aircraft to create lift more quickly and needs less runway for take-offs. Aircraft performance and responsiveness are also better in cold air.

What is a danger, though, is the conditions that accompany cold weather. We will look at these conditions in the following sections.

When Do Flights Get Cancelled Due To Snow?

If enough moisture is present in the air, freezing conditions can quickly lead to the occurrence of snow. Although a light snowfall will not cause much concern (as long as the runway remains clear), a heavy snow shower can lead to significant problems.

As soon as a layer of snow and or sludge is present on the runway, it becomes unsafe, and airport authorities will prevent aircraft from taking off or landing until the runway is cleared.

A layer of snow or sludge makes a runway slippery and can cause aircraft to hydroplane or slide when trying to take off or land, which can lead to potentially fatal accidents.

Ultimately, it is up to an individual airport’s ground control staff and pilots to make the final decision on whether or not to fly in snowy conditions.

Can Aircraft Take Off Or Land In Icy Conditions?

The same dangers and resulting restrictions that apply to snow or sludge on a runway also apply to ice on the asphalt of airports. Ice that melts often causes an ice-covered runway, as low temperatures cause it to freeze again and form a layer of ice.

Ice on a runway is even more slippery than snow or sludge, and although it poses the most significant danger for aircraft coming into land, it makes taking off very difficult as well.

What causes extended delays in these conditions is the fact that ice is very hard to remove from a runway. Ground staff is also wary of using aggressive methods to clear ice off the asphalt, as the equipment can easily damage the surface (or pavement) of the runway.

The biggest danger, however, is the icing that occurs on aircraft on the ground. The ice that accumulates on the wings, fuselage, and tail of a plane can result in a variety of problems.

The sheer weight of ice alone can cause an aircraft to lose the ability to take off, as not enough lift can be generated to carry the additional mass into the air.

Even if carrying the additional weight is possible, the ice on the wings would have deformed the shape of the wings, as well as freezing the flaps and other mechanisms used for taking off, gaining altitude, and staying in the air.

As a result, de-icing a plane becomes a necessary but time-consuming procedure that must be performed on all aircraft with any amount of ice on them.

This procedure needs to be performed very thoroughly, as even small amounts of ice left on a plane can lead to much bigger problems later on during a flight.

Can Planes Take Off In High Winds?

The answer is yes, in most cases. Modern aircraft are designed to withstand a tremendous amount of pressure caused by severe winds. Since air movement is such an integral part of aviation, pilots also get extensively trained to cope with every kind of wind condition.

There are limitations, however, when extreme wind conditions are present. Depending on the size and weight of an aircraft, combined with the wind speed, airports and pilots can set their own restrictions on when conditions are too dangerous to take off.

Why Can’t Airplanes Take Off in Extreme Heat?

Heat is probably the last thing that comes to mind when you think of possible weather conditions that will adversely affect aviation.

It has a much larger effect on takeoffs and landings than you may think. The first problem that heat creates is that air expands in warm conditions. In extreme heat, the air expands so much that aircraft cannot generate enough lift under their wings to become airborne.

The runway length required by airplanes to gain enough speed to take off or slow down after landing is just not currently available at any international airports.

Aircraft engines already generate a substantial amount of heat. When very hot conditions exist in the atmosphere, it can severely impede the engine’s performance. It includes its ability to maintain a steady rate of climb and the ability to stay airborne after takeoffs.

Extreme heat can also cause an aircraft engine to exceed its maximum operating temperature, which can cause damage, and in severe cases, lead to engine failure.

Conclusion

By answering some of the most frequently asked questions about inclement weather and air travel, this article endeavored to explain how weather affects aviation in different ways.

After reading this post, I trust you will have a much better understanding of how both airports and aircraft operations are influenced and put under pressure by increasingly volatile and extreme weather conditions.

Never miss out again when another interesting and helpful article is released and stay updated, while also receiving helpful tips & information by simply clicking on this link .

Until next time, keep your eye on the weather!

The Effects of the Weather on Aviation

Exercise 8.2.1 Read and translate the text.

Except perhaps for local or very short flights, a pilot, before taking off, obtains a weather forecast giving him the weather conditions which are expected along the route of his flight and at his destination. Because weather conditions affect aircraft in flight, to a considerable extent, special aviation forecasts are provided by meteorologists at weather offices all over the world.

The meteorologist, or forecaster, prepares a weather chart which shows the current weather conditions over the whole country. The current weather chart is called a synoptic chart. This synoptic chart shows the areas of low pressure, the areas of high pressure, where precipitation is falling, and all other weather conditions across the country.

From this weather map, the forecaster can advise pilots of the weather conditions they can expect to encounter during their flights. A high pressure area, for instance usually means good weather while a low pressure area usually involves one or more fronts producing clouds and precipitation over many hundreds of miles.

Pilots will pay particular attention to a low pressure area which lies en route, and the weather conditions associated with that low pressure area. The associated cold or warm fronts could involve clouds, thunderstorm, snow, rain, and turbulence. From his charts, the meteorologist can forecast where this weather will be at a certain time in the future, and with the help of these predictions, the pilot will decide which route to fly and when and he will know what weather conditions to expect. Should the forecast be very bad, for example, dense fog or poor visibility due to snow, the pilot may decide to postpone his flight. A pilot flying VFR would also cancel his flight because of low ceiling or low overcast conditions en route.

A pilot needs to know the wind direction and speed. A headwind will obviously delay the arrival of flights and is to be avoided if at all possible. A tailwind on the other hand, can be of great advantage as it increases the ground speed and results in a reduction in fuel consumption. Winds vary with altitude, and also from one place to another, so information on winds is very important.

Wind blowing between areas of different air pressure, has an important influence on aircraft operations. A pilot needs to know how the wind will affect his aircraft. He needs to know things about the wind: its direction and its speed. The wind direction is where it is blowing from and the wind speed is how fast the wind is blowing. ATC gives to a pilot information about the surface wind, that is the wind at ground level, in the following way: surface wind is 180/20. This means the wind is blowing from the south at a speed of 20 knots.

The words used to describe how strong the wind is are: calm, breeze, strong, gale (very strong), storm.

Calm means that there is no wind; storm means that the wind is very strong. A sudden increase in wind speed lasting only a few seconds is called a gust and the wind is described as gusting.

A squall is similar to a gust but lasts longer. ATC might pass the following information to a pilot: surface wind is 280/15 gusting 25.

Wind shear is the word used by ATC to warn pilots of a sudden change in wind direction or speed. Wind shear is a rapid change in wind speed or direction over a short distance horizontally or vertically. It can occur at any height, but is far more dangerous when encountered close the ground.

When wind shear is forecast or is reported by aircraft, ATC will warn other aircraft until such time as aircraft report the phenomenon no longer exists.

e.g. G-GD at 0745 a departing B-757 reported wind shear at 800 feet airspeed loss 20 kts.

Jet streams are high level winds which are very important for navigation because they blow very fast. They can blow faster than 200 knots.

Visibility is how far you can see in the weather conditions when you are flying. Visibility can affect flight operations.

Turbulence happens when the smooth flow of air is disturbed by something in its path on the ground or by rising or descending air.

Turbulence can be light, moderate and severe. In severe turbulence an aircraft can lose or gain a lot of height.

Clear air turbulence, or CAT, occurs at high altitudes away from clouds. It is normally associated with jet streams.

Information about significant changes in metconditions in the take-off or climb area is transmitted without delay, e.g. changes in surface wind direction and speed, visibility, RVR, air temperature, thunderstorm, moderate or severe turbulence, wind shear, hail, moderate or severe icing, severe line squall, freezing rain, sand storm, dust storm, blowing snow, tornado, waterspout.

Exercise 8.2.2 Answer the question.

1 I heard the weather forecast on the radio this morning. It said it was going to rain. Is it raining now? Does it always rain just because it is forecast? Is the weather forecast important to the pilot? To a sailor? To a motorist? To whom is the weather forecast important? What is the weather forecast for today? For tomorrow? When does a pilot need the weather forecast, before or after the flight?

2 A meteorologist is qualified to forecast the weather. Can a meteorologist forecast the weather? Can a meteorologist prepare a weather map? What can a meteorologist do? Can a farmer forecast the weather? A sailor? How does a farmer forecast the weather? A sailor? A meteorologist?

3 The current weather conditions in this area are good/poor/cloudy/overcast etc. Look out of the window and describe the current weather. Are you interested in the current weather? In tomorrow’s weather? In yesterday’s weather? Why are you only interested in the current weather and in tomorrow’s weather? Why is the pilot more interested in the weather forecast than in the present weather?

4 Does a meteorologist prepare the synoptic chart? Does he prepare the navigational hart? What chart does a meteorologist prepare?

5 Does a low pressure area bring poor weather? Does a low pressure area also bring good weather? What sort of weather does a low pressure area bring? Can a low pressure area affect an area many hundreds of miles away? Can it bring clouds/rain/snow/hail/other precipitation? Cana meteorologist show a low pressure area on his chart? Who is interested in a low pressure area? way is a pilot interested in a low pressure area?

6 Does a high pressure area bring fair weather? Sunny skies? Clear days? Does a meteorologist show a high pressure area on a synoptic chart? How does he show a high or a low pressure area on his synoptic chart?

7 Is rain precipitation? Snow? Hail? Turbulence? Wind? Name the kinds of precipitation.

8 Is a headwind in front of the aircraft? Do pilots like headwinds? Does a plane consume more or less fuel with a headwind? Does a plane go faster or slower with a headwind Does a plane arrive early or late with a headwind?

9 If headwinds are in front of a plane, are tailwinds in the rear? Are tailwinds good for fuel consumption? What winds do pilots prefer? Why do pilots prefer tailwinds?

10 If a pilot travels a distance of 100 miles in one hour is his groundspeed 100 mph? If he travels a distance of 60 miles in one hour what is his ground speed? What type of wind affects his ground speed?

11 Is a front shown on a weather map? Does a forecaster show a front on a synoptic chart? Does he show a front on the synoptic chart to the pilot? To the navigator? To the radio maintenance technician? To whom does he show a front on the synoptic chart? How many types of fronts are there?

12 Do we find cold fronts on a weather map? On a navigation map? On what sort of maps do we find cold fronts? Does a meteorologist prepare a weather map showing the cold fronts? Does a pilot prepare a weather map showing the cold fronts? Who prepares a weather map showing the cold fronts?

13 Is a warm front also found on a weather map? Can pilots recognize a warm front on a weather map? Does everyone recognize a warm front on a weather map? Who recognizes a warm front on a weather map?

14 A low ceiling means that the clouds are low. Are the clouds low today? Do we have a low ceiling? Would the ceiling today trouble a pilot? Is 800 feet a low ceiling? 15,000 feet? What do you consider is a low ceiling of clouds? What effect can a low ceiling have on flying?

15 With a low ceiling are there many clouds in the sky? Are there more clouds in the sky when the sky is overcast? Can you see any blue sky when the sky is overcast? What colour is the sky when it is overcast?

Exercise 8.2.3 What do the following abbreviations stand for?

VFR; IFR; ATC; e.g; kts; CAT; RVR.

Exercise 8.2.4 Write T if the sentence is true and F if the sentence is false.

1. A pilot, before taking off, does not obtain weather.

2. Weather conditions don’t affect aircraft in flight.

3. Special aviation forecasts are provided by meteorologists at weather offices all over the world.

4. A weather chart shows the current weather conditions over the whole country.

5. The current weather chart is called a map.

6. This synoptic chart does not show the areas of low pressure, the areas of high pressure, where precipitation is falling, and all other weather conditions across the country.

7. A low pressure area, for instance usually means good weather while a high pressure area usually involves one or more fronts producing clouds and precipitation over many hundreds of miles.

8. Pilots will pay particular attention to a low pressure area which lies en route.

9. Should the forecast be very bad, for example, dense fog or poor visibility due to snow, the pilot may decide to postpone his flight.

10 A pilot flying VFR would also cancel his flight because of low ceiling or low overcast conditions en route.

11. A tailwind will obviously delay the arrival of flights and is to be avoided if at all possible.

12. A headwind on the other hand, can be of great advantage as it increases the ground speed and results in a reduction in fuel consumption.

13.Winds don’t vary with altitude so information on winds is not very important.

14.A pilot needs to know how the wind will affect his aircraft..

15. The wind direction is where it is blowing to.

16.Wind shear can occur at any height, but is far more dangerous when encountered close the ground.

17.Jet streams are high level winds which are not very important for navigation.

18.Visibility cannot affect flight operations.

19. Clear air turbulence, or CAT, occurs at low altitudes away from clouds.

20. Information about significant changes in metconditions in the take-off or climb area is transmitted without delay

Exercise 8.2.5 Give the English equivalents for the following.

погодные условия ожидаемые по маршруту полета;

пункт назначения; влияют на самолет;

до определенного предела;

синоптик готовит погодную карту;

существующие погодные условия;

синоптическая карта зоны высокого давления;

выпадают осадки; используя эту карту;

синоптик может сообщить пилоту;

могут встретится во время полета;

обратят внимание на; связанные с зоной низкого давления;

синоптик может прогнозировать;

означает хорошую погоду;

фронты могут формировать облачность;

грозы, снег, дождь и турбулентность;

синоптик может прогнозировать;

пилот решит, каким маршрутом лететь;

какие погодные условия ожидать;

если прогноз будет очень плохим;

решить отложить свой полет;

выполняющий полет по ПВП;

из-за низкой границы облачности;

очевидно; задерживать прибытие рейса;

его следует избегать всеми возможными способами;

быть большим преимуществом;

увеличивает путевую скорость;

уменьшает потребление горючего;

дующие между зонами с различным воздушным давлением;

оказывают значительное влияние на;

откуда дует ветер;

ветер на уровне земли;

для описания силы ветра;

штиль; бриз; резкое увеличение;

резкое изменение; более опасный;

это явление больше не существует;

плавный поток воздуха возбуждается

Exercise 8.2.6 Find in the text synonyms for the following words and word combinations.

Forecaster, current weather, a synoptic chart, predictions, postpone, gale, to last, sudden change, occur, delay considerable

Exercise 8.2.7 State what part of speech of following words belong to.

a) preposition b) noun, c) adverb d) adjective

a) preposition b) verb c) article d) adjective

a) noun b) verb c) adjective d) article

a) pronoun b) article c) verb d) adverb

a) verb b) noun c) adverb d) adjective

a) adjective b) noun c) verb d) article

a) noun b) adverb c) verb d) preposition

a) noun b) preposition c) pronoun d) verb

a) preposition b) noun c) pronoun d) verb

a)adverb b) verb c) pronoun d) article

Exercise 8.2.8 Match the words and word combinations in column A with those in column B.

a)

b)

Exercise 8.2.9 Fill in the gaps with the words from the text choosing from the ones given in brackets.

1. Because weather conditions affect aircraft in flight, to a considerable extent, special aviation forecasts are _______________ by meteorologists at weather offices all over the world. (provided, given ensure).

2. The current weather chart is called a _______________ chart.( synoptic, weather, meteorological).

3. This synoptic chart shows the areas of low pressure, the areas of high pressure, where precipitation is…, and all other weather conditions across the country (falling, coming down dropping).

4. The forecaster can advise pilots of the weather conditions they can expect to _______________ during their flights. (encounter, meet, run).

5.A high pressure area, for instance usually _______________ good weather while a low pressure area usually _______________ one or more fronts producing clouds and precipitation over many hundreds of miles.(means, indicates, shows).

6. Pilots will pay particular _______________ a low pressure area which lies en route.( attention to).

7. The associated cold or warm fronts could _______________ clouds, thunderstorm, snow, rain, and turbulence.( involve, implicate, draw in).

8. A headwind will _______________ delay the arrival of flights. ( obviously, evidently, apparently).

9. A tailwind on the other hand, can be of great __________ as it increases the ground speed and results in a reduction in fuel consumption.( advantage, point, odds).

10. Winds _______________ with altitude, and also from one place to another, so information on winds is very important.( vary, change, reverse).

Exercise 8.2.10 Fill in the gaps with the related words.

1. Because weather conditions affect aircraft in flight, to a _______________ (consider) extent, ___________(specially) aviation forecasts are provided by meteorologists at weather offices all over the world.

2. The ____________( meteorology), or forecaster, prepares a weather chart

3. From this weather map, the forecaster can __________(adviCe) pilots of the weather conditions.

4. A high pressure area, for instance usually means good weather while a low pressure area usually involves one or more fronts _______________ (production) clouds and precipitation over many hundreds of miles.

5. Pilots will pay particular attention to a low pressure area which lies en route, and the weather conditions _______ (associatION) with that low pressure area.

6.From his charts, the meteorologist can forecast where this weather will be at a certain time in the future, and with the help of these _________ (predict), the pilot will decide which route to fly and when and he will know what weather conditions to expect.

7. Should the forecast be very bad, for example, __________ (density) fog or poor visibility due to snow, the pilot may decide to postpone his flight.

8. A pilot flying VFR would also_______________ (cancellation) his flight because of low ceiling or low overcast conditions en route.

9. A pilot needs to know the wind _______________ (direct) and speed.

10. A headwind will obviously delay the _______________ (arrive) of flights.

11. Winds _______________ (variation) with altitude, and also from one place to another, so information on winds is very important.

12. Wind blowing between areas of (differ) air pressure, has an important influence on aircraft operations.

13. ATC gives a pilot _______________ (inform) about the surface wind

14. This (meaningly) the wind is blowing from the south at a speed of 20 knots.

15.The words used to (descriptive) how strong the wind is are: calm, breeze, strong, gale (very strong), storm.

Exercise 8.2.11 Fill in the prepositions if necessary.

1. _______________ perhaps for local or very short flights, a pilot, _______________ taking off, obtains a weather forecast giving him the weather conditions which are expected _______________ the route ___________his flight and _______________ his destination.

2. Because weather conditions affect aircraft _______________ flight, to a considerable extent, special aviation forecasts are provided _______________ meteorologists _______________ weather offices all _______________ the world.

3. This synoptic chart shows the areas _______________ low pressure, the areas _______________ high pressure, where precipitation is falling, and all other weather conditions _______________ the country.

4. _______________ this weather map, the forecaster can advise pilots _______________ the weather conditions they can expect to encounter _______________ their flights.

5. Pilots will pay particular attention ___________a low pressure area which lies en route, and the weather conditions associated __________ that low pressure area.

6. _______________ his charts, the meteorologist can forecast where this weather will be _______________ a certain time _______________ the future, and _______________ the help of these predictions, the pilot will decide which route to fly and when.

7. A headwind will obviously delay the arrival _______________ flights and is to be avoided if _______________ all possible.

8. A tailwind can be _______________ great advantage as it increases the ground speed and results _______________ a reduction _______________ fuel consumption.

9.Wind blowing _______________ areas …different air pressure, has an important influence … aircraft operations.

10.A pilot needs to know how the wind will affect _______________ his aircraft.

11.He needs to know things _______________ the wind: its direction and its speed.

12. The wind direction is where it is blowing _______________

13. ATC gives a pilot information _______________ the surface wind, that is the wind __________ ground level, _______________ the following way: surface wind is 180/20.

14. This means the wind is blowing _______________ the south _______________ a speed of 20 knots.

15. A sudden increase __________ wind speed lasting only a few seconds is called a gust and the wind is described ____________ gusting.

16.A squall is similar _______________ a gust but lasts longer.

17. ATC might pass the following information _______________ a pilot: surface wind is 280/15 gusting 25.

18. Wind shear is a rapid change _______________ wind speed or direction _______________ a short distance horizontally or vertically.

19. It can occur _______________ any height.

20.When wind shear is forecast or is reported ___________ aircraft, ATC will warn other aircraft _______________ such time as aircraft report the phenomenon no longer exists.

21.Turbulence happens when the smooth flow _______________ air is disturbed _______________ something _______________ its path _______________ the ground or _______________ rising or descending air.

22. ______________ severe turbulence an aircraft can lose or gain a lot ______________ height.

23. Clear air turbulence occurs _______________ high altitudes away _______________ clouds.

24. It is normally associated _______________ jet streams.

25. Information _______________ significant changes _______________ metconditions ___________the take-off or climb area is transmitted __________ delay, e.g. changes _______________ surface wind direction and speed, visibility, RVR, air temperature, thunderstorm, moderate or severe turbulence, wind shear, hail, moderate or severe icing, severe line squall, freezing rain, sand storm, dust storm, blowing snow, tornado, waterspout.

Exercise 8.2.12 Make up sentences using the given words.

1. might/ the following/ ATC/ information /pass /to/ a pilot:/ surface wind is 280/15 gusting 25.

2. any/ wind/ at / can /height/ shear /occur

3.shear/ dangerous /close /far/ encountered/ when/ the ground /is/ more/ wind

5. warn/ is/ wind/ when/ shear other / forecast/ ATC/ will/ aircraft

6. because/ jet/ very/ navigation/ important/ for/ they are/ blow/ very streams/ fast.

7. blow/ 200/they /faster /than / knots. can

8. operations / affect /visibility/ can/ flight.

9. by/when /happens/ the/ is /smooth /air /turbulence/ flow /of/disturbed/something

10.In/ lose/severe/height/ aircraft or/ gain/ a lot of/ turbulence an/ can

11. without/ area/ is/ information/ significant/ in/ take-off/ or/ changes/ climb/ transmitted about/ the/ delay.

Exercise 8.2.13 Translate the following sentences into English.

1. Пилот перед взлетом получает прогноз погоды

2. Метеоролог готовит карту погоды, которая показывает существующие погодные условия по всей стране.

3. На синоптической карте видны зоны низкого давления, зоны высокого давления, где выпадают осадки и все другие погодные условия по всей стране.

4. Используя эту карту, синоптик может сообщить пилоту о погодных условиях, которые могут встретиться во время полета.

5.Зона высокого давления, например, обычно означает хорошую погоду, в то время, как зона низкого давления обычно привлекает один или более фронтов, которые формируют облака и осадки на много сотен миль.

6. Взаимодействующие холодный и теплый фронты могут вызывать облачность, грозы, снег, дождь и турбулентность.

7. Используя эти карты, синоптик может прогнозировать, где эта погода будет в определенное время в будущем.

8. С помощью этих предсказаний, пилот решит каким маршрутом лететь и когдаю

9. Он будет знать, какие погодные условия ожидать.

10. Если прогноз будет очень плохой, например, густой туман или плохая видимость из-за снега, пилот может решить отложить свой полет.

11. Пилот, выполняющий полет по ПВП, отложит свой полет из-за низкой границы облачности или из-за сплошной облачности по маршруту.

12. Встречный ветер будет, очевидно, задерживать прибытие рейса и его следует избегать всеми возможными способами.

13. Попутный ветер, с другой стороны, может быть большим преимуществом, так как он увеличивает путевую скорость и приводит к уменьшению потребления горючего.

14. Ветры изменяются с высотой и также от местонахождения, поэтому информация о ветрах очень важна.

15.Ветры дующие между зонами с различным воздушным давлением оказывают значительное влияние на выполнение полетов.

16. Пилоту надо знать, как ветер будет влиять на его самолет.

17. Это означает, что ветер дует с юга со скоростью 20 узлов

18. Слова, которые используются для описания силы ветра: штиль, бриз, сильный, штормовой (очень сильный), шторм

19. Штиль означает, что ветра нет.

20. Шторм означает, что ветер очень сильный.

21. Резкое увеличение скорости ветра, которое длиться только несколько секунд называется порыв.

22 Шквал подобен порыву, но длится дольше.

23. Сдвиг ветра это слово, которое используется УВД, чтобы предупредить пилота о резком изменении направления и скорости ветра.

24.Сдвиг ветра это резкое изменение скорости и направлении ветра на коротком расстоянии горизонтально или вертикально. Он может возникать на любой высоте, но он более опасный, когда встречается близко у земли.

25. Когда сдвиг ветра прогнозируется или доложен бортом, УВД будет предупреждать другие самолеты до того времени, пока ВС не доложит, что это явление больше не существует.

26. Во время сильной турбулентности самолет может сильно потерять или набрать высоту.

27.Турбулентность чистого неба или CAT возникает на больших высотах вне облачности.

28. Информация о значительных изменениях в метеоусловиях в зоне взлета или набора высоты передается без задержки.

Exercise 8.2.14 Make up your own sentences using the words and word combinations.

Forecaster, current weather, a synoptic chart, predictions, postpone, gale, to last, sudden change, occur, delay, considerable, involves one or more fronts, precipitation, pay particular attention to, the associated cold or warm fronts, dense fog, to postpone his flight, an important influence on, affect his aircraft, a reduction in.

Exercise 8.2.15. What do these words and word combinations state for:

Synoptic chart; Headwind; Meteorologist; Front; Weather forecast; Precipitation; Overcast; Current weather conditions; Area of low pressure (low pressure area); Ceiling; Area ofhigh pressure (high pressure area); Cold front; Tailwind; Warm front; Ground speed;

Exercise 8.2.16 Retell the text.

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