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Студенческий документ № 012361 из АГЗ МЧС России

Construction of Aircrafts

In the dynamic world of today, aviation provides a rapid transportation link between different population centers, comple menting a road and rail transportation network. In many places the airplane is the only known vehicle for the large-scale movement of passengers and freight over large distances.

The major components of airplanes can be divided into six main parts: fuselage, wings, empennage, flight controls, landing gear or floatation gear, and nacelles. (See Fig. 1.)

The fuselage is the main body of the airplane and contains the pilot's compartment (cockpit) and passenger and baggage compartments. The cockpit contains the flight controls and instruments. The larger part of the fuselage contains passenger seats or cargo space and usually some provision for baggage. The wings are the main lifting surfaces which support the aircraft in flight, and they are attached to a strongly-built or stressed section of the fuselage. The empennage, more commonly known as the tail section, consists of a vertical stabilizer and rudder and the horizontal stabilizer and elevators.

The three basic flight control surfaces are the ailerons, the elevators, and the rudder.

The ailerons are located at the trailing edge and near the tips of the wings. When one is raised, the other lowers, and the airplane banks or rolls. The lowered aileron increases l i f t causing the wing to rise, while the raised aileron reduces lift, causing that wing to drop. These modifications to the airfoil impose additional drag. The lowered aileron presents a relatively greater amount of drag than the raised aileron, resulting in a tendency to skid. To overcome this, a differential control mechanism causes the up-aileron to move a greater distance than the down-aileron for a given control movement.

The elevators are hinged to the horizontal stabilizer and control the airplane's movement up and down about the lateral axis. When the control stick is moved forward, the elevators lower, and the airplane dives, and vice versa. Because more force is necessary to climb than to descend, on most airplanes the maximum number of degrees the elevators can be raised is greater than the maximum number of degrees they can be lowered. Thus, the stick can be pulled back farther than it can be pushed forward. Where necessary, the pilot is aided in moving this control by a differential mechanism. Many newer aircraft possess a different method of controlling pitch. This method combines the horizontal stabilizer and the elevators into a single surface known as the controllable horizontal tail. This surface gives easier manoeuvring of the aircraft at transonic speeds. The whole surface can be repositioned from the cockpit when inflight trimming is necessary.

The rudder is hinged to the vertical stabilizer (fin), and it controls the movement of the airplane around the vertical axis. The right pedal moves the rudder and the aircraft to the right. The left pedal works similarly.

The main landing gear or wheels are attached by struts and braces to the fuselage and often to the wings outboard of the fuselage. Usually a smaller wheel supports either the nose or tail of the airplane.

Flotation gear for landing on water consists of pontoons or floats. Some airplanes are equipped with skis for landing on snow.

Nacelles are compartments housing the power plant or engine and its accessories. The nacelle is usually covered with a detachable cowling and contains a framework or engine mount which is attached to the fuselage or airframe.

Fig. 1. Turbojet Airplane Components

1 - elevator; 2- stabilizer; 3 - engine nacelle; 4 - aileron; 5 - wing; 6 - undercarriage housing; 7 - leading edge flaps; 8 - fuselage; 9 - fin; 10 - rudder; 11 - main undercarriage wheels; 12 - nose wheels; 13 - crew's canopy

.........................................................

5. Wher e are the ailero ns locat ed?

6. What do the

eleva tors contr ol?

7. What does the rudde

r contr ol? 8.

What

supports the nose or tail of the airplane?

9. What are some airplanes equipped with for landing on snow?

10. What do nacelles house?

AIRPORT

An airport is a location where aircraft such as fixed-wing aircraft, helicopters, and blimps take off and land. Aircraft may be stored or maintained at an airport. An airport consists of at least one surface such as a runway, a helipad, or water for takeoffs and landings, and often includes buildings such as hangars and terminal buildings.

Larger airports may have fixed base operator services, seaplane docks and ramps, air traffic control, passenger facilities such as restaurants and lounges, and emergency services. A military airport is known as an airbase or air station. The terms airfield, airstrip, and aerodrome may also be used to refer to airports, and the terms heliport, seaplane base, and STOL port refer to airports dedicated exclusively to helicopters, seaplanes, or short takeoff and landing aircraft. In some jurisdictions, the term airport is used where the facility is licensed as such by the relevant government organization (e.g. the U.S. Federal Aviation Administration (FAA), Transport Canada). Elsewhere the distinction is one of general appearance. Other jurisdictions define an airport by its having the customs offices etc expected of a port though the more general term is airport of entry.

Airports There are many airports in our country. There are some inter national airports. There is an aerodrome, a terminal, some buildings and offices at the airport; on the aerodrome there are some taxi ways and runways. Runways are 2,000 km long and more. Some taxiways are long, other taxiways are short. There are hangars there. There are beacons, too. At the; terminal there is an apron, on it there are many stands for aircraft and there are pads for helicopters. At every aerodrome, there is a meteorological office, a tower and a fire station. There is a settlement for the personnel and a hotel for passengers and crews at every airport. The airport is not far from the city. It doesn't take much time to get to the airport. It may be a 20 - 40 minute drive by bus or train.

Frankfurt airport

Frankfurt Airport is airport number 3 in Western Europe. There are about

5,000 flights to and from some 170 cities in 80 countries every week. There are 40,000 passengers a day. Boeing 747 planes land and takeoff here. This aircraft is for 490 passengers. There's a new terminal for 24 million passengers. There are 3 landing areas for 36 aircraft. There's a special hangar for B-747. There's a control tower 34 m high. There are 900 air traffic specialists to control flights.

Paris airport

.

Paris Airport consists of three airports: Orly, Bourge and Roissy. Orly and Bourge service Paris and its area. The aircraft of 160 air companies make regular flights to these airports. Over 13 mil passenger; use the airport every year and every year about 300,000 aircraft take off and land here. Now the airport has modern equipment and technical buildings to control the aircraft of all types. In Orly there are four runways and a control tower controlling the traffic in the airport area. The passenger terminal building services over 10 mil passengers a year. The area of Bourge airport is smaller, there are two runways. It services over 3 mil passengers a year. At Bourge Airport there is the International Exhibition Area. Aviation and Space Equipment Show takes place every two years. Roissy is a new airport. Its area is 3,000 hectares. It services over 50 mil passengers and 2 mil tons of cargo a year. To service such a number of passenger; the airport has five runways, four of which are parallel. 150 planes take off and land here every hour. The passenger terminal is very comfortable. There is everything to take a passenger from a car to the aircraft quickly and comfortably.

Modern airports

The modern airport is a center of most diversified services. Among the airport services are: flight assistance service, air traffic control - airport traffic control, approach control, air route traffic control; radio communications and weather service observation and forecasting. The airport has to maintain a num8 ber of supplementary services - risque and security services. There must be an airport clime, a fire brigade, special vehicles and equipment units (water trucks, catering trucks, air freight and baggage handling units, tow tractors for moving aircraft to the apron). Other services cover maintenance, overhaul and repair of stationary and mobile equipment, the supply of electricity, water, heat and air conditioning. There is the Aircraft Maintenance Base with many maintenance specialists. There's the fuel supply center with underground pipelines. The facilities include runways, air navigation aids, and passenger and cargo terminal buildings. The airport offer: a hotel, a post office, bank offices, restaurants, snack bars, car rental firms and a number of other facilities from pharmacy to the travel office, from the barber and beauty shop to the supermarket and waiting lounges. There must be everything for quick passenger handling. The modern passenger air terminal operates a-dozen of services. In the reception, halls at die check-in desks the suitcases are weighed and labeled. Baggage check-in facilities utilize conveyors to move baggage without delays. In the terminal there's an electronic flight information board to list departure and arrival times. Near the board (here are departure areas for passengers to board their flights. Passengers board the aircraft via loading bridges (passageways or fingers). The baggage claim carousel is on the lower floor. Flight numbers enable passengers to find their luggage location easily. It has become difficult for travelers to locate various facilities and services they need. The ICAO Council has developed uniform signs for use at international airports to facilitate travelers: ARRIVALS; DEPARTURES; FIRST AID; NURSERY POINT; PASSENGER CHECK-IN; ELEVATORS; HOTEL RESERVATIONS; LOST AND FOUND; LEFT LUGGAGE and so on.

Sheremetyevo

The capacity of Sheremetyevo Airport has increased. The terminal can receive up to 2,100 passengers every hour; the total capacity of the complex is 15 mil passengers a year. Sheremetyevo II is situated 28 Ian northwest, of Moscow. It is the centre of international air traffic of Russia. Sheremetyevo II was inaugurated in 1980, its capacity is 2,100 passengers an hour, and it can handle 6 mil passengers a year. It's a 9-storey building with 19 telescopic ladders (fingers). It has been assembled by the West German firm. It has the most up-to-date equipment for handling passengers. There is a new runway which can handle all types of aircraft. Radio navigation equipment and the traffic control system have been modernized. The new check-in counters, computers and 10 automatic luggage conveyors cut the time needed for receiving passengers and handling luggage down to 5 minutes. The automatic baggage conveyors reduce luggage waiting time after arrival to 7 minutes. There are halls for passengers, 4 restaurants, a banquet hall, bars, snack bars to cater for 1,600 passengers at a time. There's a conference hall for 500 seats. There's a hotel for 500 transit passengers, a modern complex for centralized fueling of aircraft, engineering communications and other facilities. There are arrivals, departures, transit and waiting halls in the terminal. The terminal has all the latest equipment to handle numerous passengers, much cargo and baggage. Boarding is done through one of the 19 passages (telescopic gangways). There are foreign airline offices, on the upper floors. There is a parking place for 1,200 cars. It takes only 35 minutes to get to the centre of the city. Ticket registration and luggage weighing and labeling are computerized. There's the computer information system to provide passengers with necessary flight information. Passengers can make a long-distance telephone call; send a cable, exchange currency, buy souvenirs and other goods at the duty-free shops. There are two sections for kids with sleeping rooms and playgrounds. Payment of shipment is accepted in cash, che12 que or letter of credit. Sheremetyevo-I, Domodedovo, Vnukovo were used for domestic lines only; Sheremetyevo-II is one of four major airports in Europe.

Airports of the UK

There are 8 major airports in Britain - Heathrow, Gatwick, Stansted Southampton, Prestwick, Glasgow, Edinburgh and Aberdeen. Southampton airport was purchased in 1990 by BAA. The seaport has an old terminal building which was built in 1917. Their plan is to replace completely all the airport facilities. The plan costs $ 20 million. There will be a new passenger terminal, a control tower, car parking areas - a completely new airport will be built around the old runway. There is a station which provides 55-minute non-stop train services to London. Southampton is the UK's fastest growing airport. They have installed an instrument landing system. A new hotel is to be bunt next to this terminal. Local people can fly to European destinations from Southampton. Southampton has become an important air freight centre. Traffic has greatly increased. They have introduced a weekly transatlantic service. Flights are to operate non-stop to Toronto. New facilities are installed including shops and catering points. Stansted is one of the most comfortable and easy to use airports. Departures are on the left, arrivals on the right. Everything you need is on one level. Passengers walk from the entrance through check-in, security and Passport Control to the departure lounge, the distance of 150 meters. From the departure lounge an automatic transit sate system will carry passengers quickly to the apron where they'll board their plane. Stansted is ideally located; it takes 41 minutes by train from London. There are 12 new European destinations and holiday flights are also offered.

Heathrow airport

It is 24 km west of London center. There are 125 parking stands. There're 3 terminals. Terminal I and Terminal II are for short haul routes, Terminal III is for long haul routes. Heathrow services about 27 mil passengers a year. 45,000 people work at Heathrow, in its 260 offices. There're 74 airlines offices with cargo agents, salesmen, charwomen typists, mechanics, medical personnel, policemen, Customs officers, Passport Control officers, etc. One of the most important problems of Heathrow is the noise of aircraft. There are some restrictions for night flights. The aircraft engines are becoming quieter. Another problem is the congestion of Terminal III, the terminal is overcrowded, and it handles about 10 mil passengers a year. A new 4-th terminal is planned, it can handle 2,000 passengers an hour and its capacity is 8 mil passengers a year. It can receive the biggest aircraft. There are 22 stands.

Gatwick Gatwick is 45 km south of London. It was inaugurated in 1936. It is connected by railway with the center of London. Its capacity is 16 mil passengers a year, but when a new terminal was opened, its capacity has increased to 25 mil. It can handle 8 wide body aircraft simultaneously. Gatwick's main runway is 10,165 feet long. It handles 40 aircraft movements per hour, while the northern runway handles 18 per hour.

Planning a large modern airport

The problem today is to learn to look forward at least 30 years into the future. The crowded condition of the airways is being repeated throughout the world. More passengers should be carried per aircraft unit in order not to increase the number of aircraft units flying. The costs of aircraft have changed radically in the past few years. Every minute of the aircraft life must be considered as of great economic value. To do reasonable planning, it is necessary to know what aircraft of tomorrow may be. The second planning problem is run14 way limitations. The runway must be planned to provide a very high driving speed. Of next concern are taxiways, the avoidance of delays on a taxiway, awaiting runway clearance. The next problem is the apron. An apron layout should be studied carefully to avoid the trapping of aircraft between fingers. To eliminate apron delays the design of a round building is preferred. Air cargo is a major factor m the growth of the airport in the future. It is also of concern to handle cargo safely and quickly.

AIRCRAFT INSTRUMENTS

Aircraft instruments are basically devices for obtaining information about the aircraft and its environment, and for presenting that information to the pilot in a concise form. Their purpose is to detect, measure, record, process and analise the variables encountered in flying an aircraft. They are mainly electrical, electronic or gyroscopic. They are concerned with the behaviour of the engines, the speed, height and attitude of the aircraft and its whereabouts.

The history of the development of aircraft instruments shows a movement away from instruments that merely obtain and present information to those that automatically do something about the in formation they receive. For example, at one time an instrument would have told a pilot that his aircraft was nose-down and it would have been left to the pilot to take corrective action manually if necessary. Nowadays it is often the case that a pilot will "instruct" an automatic system, for example, to f l y level, and the appropriate instrument will usually show the "instruction" is being "obeyed" and only exception ally that something is wrong because the automatic system has failed.

A modern aircraft cockpit looks on first sight to consist of a be wildering array of instruments that no human being could ever master or understand. It looks as though so much information presented simultaneously could never be absorbed by a small team of two to four people with any certainty. However, instrument panels are designed in such a way that instruments are grouped logically so that to a pilot it is an "open book".

Instruments Concerned with Flight Information

Height. An instrument for measuring and showing height above a level of reference is called an altimeter. It is basically an extremely sensitive aneroid barometer which measures static pressure at the height the aircraft is flying and, according to the difference between this and the pressure at a predetermined reference level, indicates height above reference level. There are three possible reference levels. The first is a theoretical mean sea-level reference which is of no use on landing. The second is true pressure at airfield height so that the altimeter reads zero on landing. The third is true pressure at sea-level so that the altimeter indicates true altitude on landing.

A radio altimeter measures height above terrain and so would not help in maintaining a constant flight-level over land. Its purpose can be stated quite simply as that of measuring the depth of air immediately below the aircraft, rather as sounding devices in a ship are used to measure the depth of water beneath its keel.

Vertical Speed. The rate of change in altitude is measured and shown by a vertical speed indicator. This indicates the speed of climb (ascent) or descent (dive or glide).

Horizontal Airspeed. Horizontal airspeed is measured and shown by an airspeed indicator (ASI). The ASI is an aneroid capsule which measures the difference between static pressure and the pressure inside an openended tube, called Pitot tube, usually situated on or underneath the nose of the aircraft. The airspeed indicator tells the pilot what his airspeed would be if he were flying at sea-level under standard atmospheric conditions, temperature 59°F (15°C) and barometric pressure 29.92 inches (760 mm). True airspeed (TAS) may be calculated approximately from indicated airspeed (IAS) by adding 2 per cent to the IAS for every one thousand feet above sea-level.

The machmeter indicates the Mach number which expresses airspeed as a fraction of the speed of sound. It is essential equipment on jet aircraft.

Turning Characteristics. Aircraft turning characteristics can be measured and shown by a simple device known as a turn-bank indicator. The turn-bank indicator tells the pilot two things. Firstly, it tells him whether he is doing a tight turn or a wide turn, and whether it is to port or starboard. Secondly, the turn-bank indicator tells the pilot whether, on the turn to right or left, his aircraft is slipping inwards or skidding outwards. In big aircraft information on turning and banking is incorporated in a flight system direction indicator.

Attitude. The attitude of an aircraft relative to the surface of the earth is shown by an "artificial" or "gyro" horizon. There is a horizon bar on the instrument that always remains parallel to the surface of the earth. Another small piece of metal shaped to indicate the aircraft appears above or below the horizon bar if the airplane is in a climbing or gliding attitude. When the aircraft is banked to the left or right the imitation airplane in the instrument appears banked to the left or right.

Direction. An elementary direction-measuring instrument is a simple magnetic compass which may, however, be inaccurate by a degree or two in straight and level flight and much more inaccurate in turns. The magnetic compass is used in conjunction with a directional gyro which is not affected by the angles of bank normally employed in airlines.

Instruments Concerned with Propulsion Information

Speed. Engine speeds are measured and shown on rpm indicators which measure the revolutions per minute of the main rotor in each engine. Any differences in rpm from a master engine used as a basis for synchronizing are shown on a synchroscope.

Temperature. The temperature of each engine on an aircraft is measured and shown on a temperature indicator. Piston-engined aircraft have indicators for cylinder head temperature (CHT). Turbine engines have indicators for jet-pipe temperature (JPT) or turbine-gas temperature (TGT). All types of engines have oil temperature indicators showing the temperature of their lubricants.

Pressure. Various sorts of pressure occurring in a piston engine in operation are shown by instruments. A manifold pressure gauge is an instrument for measuring the absolute pressure in the induction system (a branched pipe for distributing air or a mixture to a number of cylinders) at a point standardized for each engine. Alternatively boost pressure, which is pressure in the induction system at a point standardized for each type of engine may be shown on a boost pressure gauge. Oil pressure is indicated by an oil pressure gauge.

Instruments Concerned with Information about Fuel

Fuel Content. Fuel tank contents indicators show how much fuel the aircraft has left at any moment of time. Usually each tank is metered individually and the amount of fuel is measured in litres or by weight.

Fuel Flow. The fuel consumption of each engine is measured by fuel flowmeters calibrated in kilos per minute. These are integrated in a device to indicate kilos gone since engines were started.

Instruments Concerned with Information about Conditions on the Outside of the Airframe

Temperature. The outside air temperature (OAT) gauge gives the pilot general information about the temperature of the air immediately surrounding the airframe.

This will enable him to assess the influence of temperature on certain performance aspects of the aircraft. He needs to know particularly whether the temperature is within certain limits in humid conditions so that there is danger of ice forming. This enables action to be taken to heat the affected areas. Critical parts include the leading edges of the wings, control surfaces of the tail unit, engine air intakes and the pitot head.

On the other hand there are certain parts of the airframe that might possibly become overheated because they are close to something like an engine or a generator producing a lot of heat. The temperature of important zones of the airframe in the vicinity of a heat-producing component, for example the rear spar of a mainplane containing a "buried" jet engine, are monitored by electrical temperature bulbs.

Cabin temperature indicators are normally fitted to modern aircraft to enable the pilot to confirm that the automatic system controlling temperature is in working order. Cabin humidity indicators may be fitted but humidity control systems are rare.

Pressure. It is important to know the pressure inside the passenger cabin because it must be neither too high nor too low for human comfort. It is also important to know the difference between the air pressure outside the cabin and the air pressure inside it because it represents a force exerted in normal circumstances in an outwards direction.

The difference in pressures must be kept within limits imposed by the strength of the fuselage. The cabin altitude indicator is the instrument monitoring passengers' comfort and the cabin differential pressure indicator monitors the margin of safety. Other pressures concerned with the airframe that have to be watched are the hydraulic and pneumatic systems used in powering controls of such moving parts as brakes, undercarriage and so on.

Instruments Concerned with Information about the Aircraft's Electrical System

Voltage. Direct current and alternating current voltages are measured and shown by AC and DC voltmeters. Where information is required only periodically from a number of points it is usual to have only one voltmeter with a device for selecting each point of measurement as required.

Current. The instrument that measures an electric current in amperes is called an ammeter.

We may summarize the nature of information presented by aicraft instruments as follows:

(a) it may be continuous presentation, as in the case of a gyrohorizon. (b) it may be on-tap presentation, as in the case of moving a switch for a particular reading on a voltmeter.

(c) it is always concerned with situations that are expected to change within certain limits, for example temperature. (d) most is presented visually.

Attempts are made to minimize the heavy demands made on the aircrew's use of their eyes by employing their senses of hearing and touch. Unfortunately at the same time there are ever increasing demands on hearing coming from the various radio aids now installed in aircraft.

However, some of the instruments for alerting aircrew to the fact that something abnormal is happening do employ the senses of hearing and touch. Throughout the aircraft there are various heat, flame and smoke detectors which relay their warnings to the pilots by bell as well as by light. If for some reason or other the undercarriage has not been lowered for an intended landing, in addition to a warning light sometimes a horn is operated by the throttle setting. If the speed of the aircraft inadvertently drops below what is regarded as safe, a mechanical instrument called a stick-shaker, operating from a device on the underside of a wing, gives warning of a pre-stall condition by shaking the control column. On the other hand warning of excessive speed is given by means of a horn.

The history of aircraft development is, among other things, the change from manhandling aircraft to the automatic handling of an aircraft. The history of the development of aircraft instruments shows a movement away from instruments that merely obtain and present information to those that automatically do something about the information they receive. A notable exception to this general trend is a flight recorder which does not present information at the time of obtaining it , but stores it away for future reference.

The need for flight recording has been recognized in aviation for a very long time. Early methods of meeting this need were by the pilot or observer recording data normally on a notepad, or by relatively crude pen recorders or even a camera photographing the pilots' instruments or duplicates of them.

Today, nearly all commercial aircraft are required to carry a recorder whose performance far exceeds the maximum capability of these simpler devices. All the pilot sees of it is a small control panel on which he can set some dials which correspond to the date and flight number. This information is inserted on the recording medium before every flight and the recorder can detect whether the aircraft is flying and switch itself on or off accordingly. Data collected at any point on the aircraft are transmitted electrically to a central electronic unit where they are converted to a binary code similar to that used in computers. This ensures that accuracy can be of the order of 1 part in 1,000. It is stored in this form in an almost indestructible store normally consisting of an armoured cassette containing about 50 miles of hair-thin magnetic steel wire operating on the same principle as a tape recorder. This cassette can be removed from the aircraft at any time for decoding and analysis. Any lengthy or repetitive analysis work involved is carried out by computer.

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391 Кб, 1 декабря 2013 в 21:04 - Россия, Москва, АГЗ МЧС России, 2013 г., pdf
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