SOME WORDS ABOUT EARLY FLYING
It is known that the desire to fly is as old as humanity. Observations for flying birds gave man the idea of human flight. Every nation has many legends and tales about birdmen and magic carpets. The earliest of these legends comes from China.
One of the most famous Greek legends is the legend of Daedalus and Icarus who made wings and fastened them on with wax. Daedalus landed in safety. Icarus was not so careful as his father and he flew closer and closer to the sun. The closer he was the hotter it became. The wax melted, his wings came off and he fell into the sea.
It is clear that in those old days people knew little about nature. They could not understand much about the air and its nature and were unable to explain most of the phenomena of nature.
As time went on there came a stage when people no longer regarded flight as a supernatural phenomenon. The desire to fly was the desire to control nature. People imitated birds when they used wings. They had to fight against many prejudices because there was common belief that man could not fly.
The first scientific principles of human flight appeared in the 14th century. The great scientist Leonardo de Vinci recorded a few of them. He found that a knowledge of the air and its currents helped to understand the phenomenon of flight.
Daedalaus was a Greek; Garuda was Indian; Leonardo de Vinci Italian; Lilienthal was German; Montgolfier and Bleriot were French; Hargrake was Australian; Captain Mozhaiski was a Russian; the Wright brothers were American. They were the pioneers. Nor is this the end of this truly international story. The air captured the imagination of all. It was the efforts of men of many countries who pioneered civil aviation, who brought it to the art that we know today, and who now help its rapidly developing growth. The aeroplane is a creature of no one country's knowledge and effort. So it became clear from the very start that without international agreement the development of aviation would be greatly limited. The most successful attempt came in 1944 at a Conference of 52 nations held in Chicago, at the invitation of the United States. It was at this conference that the International Civil Aviation Organization was created.
In November 1944 in Chicago 52 nations signed the Convention on International Civil Aviation. The 96 Articles of the Convention provide for the adoption of international standards and recommended practices. It was decided that ICAO would come into being (start working) after the Convention was ratified by 26 states. It happened on the 4-th of April in 1947. Montreal was chosen as the headquarters of the Organization.
The ICAO activities are numerous. The main task is to provide the necessary level of standardization for the safe and regular air operations. SAHRS (International Standard and Recommended practices) regulate air navigation, recommend installation of navigation facilities and suggest the reduction of customs formalities. International standards must be strictly observed by all member States. Recommended practices are desirable but not essential.
ICAO has a Sovereign body, the Assembly, and a governing body, the Council. The Assembly meets once in 3 years and reviews the work in the technical, economic and legal fields in detail.
The Council is a permanent body composed of representatives of the Contracting states. Its first President was Edward Warner.
The Council is assisted by the Air Navigation Committee, the Legal Committee, the Committee on Unlawful Interference and some others. One of the major Council duties is to adopt International Standards and Recommended Practices. It may act as an arbiter between Member States. And, in general, it may take any steps necessary to maintain the safety and regularity of air operations.
There are 18 Annexes to the Convention, they cover all aviation problems.
The Secretariat staff, headed by the Secretary General, provides the permanent organizational work. ICAO has 6 regional offices. The working languages of ICAO are English, French, Spanish and Russian.
In 1958 the Warner Awards were established by ICAO for outstanding contributions to international civil aviation.
SOME CIVIL AVIATION ORGANIZATIONS
1. IATA - International Air Transport Association is the second in its importance organization after ICAO for international civil aviation. It was founded in 1945 and is uniting world airlines. The main objective of this organization is to provide safe and regular development of civil aviation and cooperation of world airlines. The IATA Technical Committee deals with the problem of safety, standardization of aviation equipment, training of flying personnel, communications, meteorology, aerodromes, navigational aids, etc.
2. International Civil Airports Association (ICAA) is the major international airports association. It is an organization permitting a constant exchange of experience, information and documentation among airports as well as contacts between airport managements. Founded in 1962 ICAA is doing much to help countries in developing both domestic and international airports providing specialists and equipment.
3. International Federation of Air Traffic Controllers' Associations (IFATCA) was founded in 1963 with the purpose to enable the national associations to study and solve the problems for the development of air traffic control art and to create a better understanding among the controllers serving the international aviation.
4. Eurocontrol is the European organization working for air navigation safety. It was created in 1963 for better service of European airspace. The increase of fast flying civil transport aircraft brought a number of difficulties and resulted in the necessity of new operating methods and use of advanced technology. Some European countries signed an agreement to organize common air traffic control in the upper airspace.
There are very many met. stations all over the country. They are of great help for aviation. There is a met. ground at every airport too, which is equipped with special instruments. These grounds have to be located not far from the landing and take off areas at a distance of about 300 m. from the end of the runway. At the airports which have no landing systems these met. stations are situated not far from the dispatch office. But if it is difficult to watch the horizontal visibility from this point, then the observations must be made from another place which is the most suitable one for observations. These met. observations are made every 30 minutes at the airports; but sometimes when the weather is dangerous for safe flights the observers give met. information every 15 minutes. All flights must be provided with met. information about the actual weather and weather forecast.
The chief pilot studies the data obtained during preflight preparation. Besides, the pilot receives met. report while in flight. 20-30 minutes before entering the aerodrome area the controller gives full information about the weather for the aerodrome to the plane. For the planes approaching for landing met. report is constantly given with the help of a tape-recorder or by a controller.
Short-flight forecasts are provided by continuous Transcribed Weather Broadcasts and the Pilot's Automatic Telephone Weather Answering Service.
For longer flights a telephone call or visit to the nearest Flight Service Station or Weather Bureau Airport is necessary.
After receiving weather information either for short or long-range flights the pilot considers carefully if weather conditions are suitable for his flight. If not, it is better to delay the flight.
At many terminals information helpful to landing and take off is continuously broadcast on a navigational aid frequency. Prior to descent the pilot requests current weather for terminal area as well as field conditions at destination.
THE EFFECTS OF THE WEATHER ON AVIATION
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 inform 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.
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.
Pilots will pay particular attention to a low pressure 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 on route.
Air navigation came into existence alongside with air traffic. It had a humble beginning, but in a little more than 50 years has come today's extensive aircraft industry, a vast network of global airlines.
In the early days of flying, serious accidents often occurred because men were not thoroughly familiar with the new medium of transportation.
Today pilots are familiar with the construction of the aircraft, its controls, and its limitations. Competent instructors are available to give this information as well as to give actual flight instructions. The manuals are based not only on sound theory but also on long experience. They should be obtained and carefully studied.
The directing of aircraft from one place to another is the science of air navigation.
In fair weather and during daylight, it is usually not difficult to fly from one place to another by visual reference to landmarks noted in the charts. In bad weather and in the hours of darkness, the usual landmarks are often lost to view. Even the airport of the destination may be closed.
If air transportation is to function safely and with any degree of regularity, some aids to navigation, including instrument landing facilities, must be made available.
With the installation of instrument landing systems at principle terminals, and with other equipment such as radar and radar beacons, we may confidently expect that air transportation soon will become independent of all but the most severe weather conditions.
METHODS OF NAVIGATION
Learning to fly occupied the minds of men almost from the beginning of recorded history. Legend tells of magic carpets and winged sandals. History brings us stories of flying machines, but man’s first powered flight in a heavier-than-air machine was made in 1903.
This flight lasted for 12 seconds and covered a distance over the ground of only 120 feet. This flight was made against wind of 24 mph and was equal to a flight of 540 feet in still air. The maximum altitude attained was 12 feet above the ground.
In the old days pilots listened to the winds in the wires and were happy to fly at any speed. But now a fast flying aircraft pushes through the atmosphere so rapidly that the air can't get out fast enough, because the air is compressed and heated by the compression. At such great speeds it's not so easy as before to pilot the plane, to determine the geographical position and to maintain desired directions to navigate.
Through centuries 4 principal methods of navigation have been developed. They may be briefly described as follows:
1. Pilotage, by which the pilot is directing the aircraft with the reference to visible landmarks.
2. Dead reckoning, by which the distance and direction are determined between two known positions, or in which position is determined from the distance and direction from a known position.
3. Radio navigation , or the determination of position by means of radio bearings, distances or time intervals.
4. Celestial navigation, in which position is determined by means of sextant observations of the sun, moon, planets, or stars, with exact time of the observations.
Ever since the time when people found their way by using a column of smoke by day and fire by night, navigation, navigational techniques, and navigational aids have been the subject of discussion.
What is navigation? - Navigation is the art of determining the geographical position and maintaining desired direction of an aircraft relative to the earth's surface.
A navigator belongs to the flying staff of the crew. He performs his duties by means of navigational aids and different instruments installed along the airways as well as in a plane and by making numerous calculations. That's why a navigator must know technical aids of air navigation and methods of their application during flight perfectly well. He should make navigational preparations for flight in good time. The navigator's duties performed by him during flight, are rather numerous: he must navigate the plane according to the flight plan from take off to touch down; control the progress of the aircraft by means of all established navigational methods and technical aids. He must know and observe the rules of radio communication and keep watch on airborne aids. The navigator has to get flight charts prepared personally and in advance. In addition to all duties mentioned above he must make a correct estimate of the meteorological situation.
In the course of preliminary preparation of the crew for flight the navigator together with other members of the flying staff studies the order of conducting flight on a given airway and radio aids available. Navigator's task is to determine aircraft's position, direction and speed of flight.
Usually navigators fly on heavy planes. As aircraft become larger and faster, requirements to navigator's work increase. Longer flights sends out radio waves and then measures the amount of time that it takes for the waves to return.
A radar set includes a transmitter and a receiver. The transmitter sends out at regular intervals short pulses of high-frequency waves. These can penetrate clouds and darkness. They move out in a straight line. Having met some object they are reflected back to the radar set and are translated into a spot of light on the screen.
Ground radar is used to guide planes to a landing in bad weather.
1. Master piloting technique and aeronavigation to ensure safe flying.
2. Observe pre-flight rest.
3. Be able to analyze and correctly assess meteorological and aeronautical environment situation.
4. Get ready for the flight to the full extent.
5. Control the condition and readiness of the aircraft and its proper loading.
6. Know radiotelephone phraseology and the rules of communication.
7. Inform the captain about all malfunctions of aircraft systems and instruments and make suggestions of their removal.
8. Make decisions and act according to the situation if the captain cannot perform his duties due to various reasons.
9. Inspect the aircraft after landing and taxying to the stand.
Co-pilot has the right:
1. To pilot the aircraft at all stages of the flight with the captain’s permission.
2. To fulfil the captain’s instructions when the captain cannot perform his duties.
Co-pilot is responsible for:
1. Meeting the requirements of all regulation documents of Civil Aviation.
2. Discretion while taxying and in flight.
3. Timely and correct actions at the decision height together with the captain.
4. Maintaining flight parameters given by the captain.
5. Safe completion of the flight while piloting when the captain cannot fulfil his duties.
To talk about the air traffic controller's role is, of course, important. Controller's functions are very numerous and rather difficult. It is known that great technological achievements have been reached. But speaking about full automation in the field of aircraft operations and air traffic control one must remember that electronic devices cannot replace man. They can only be an auxiliary to the human operator. Increasing air safety is the main task of controllers. Some people see the answer to ATC problems in large radars with enormous coverage (range). This will require navigation system with air-ground data links so that position information is the same in the air and on the ground. The task of the controller then will be separating aircraft from each other and maintaining a safe and orderly flow of traffic. The role of the controller in the future is becoming that of a monitor, he will interfere only when needed. So he will be a necessary element in the air traffic control process.
RADIO NAVIGATION AIDS – VOR/DME
Navigation is the directing of aircraft from one place to another along a particular line of travel. To navigate a pilot uses radio navigation aids. There are a variety of different types of radio navigation aids. Here are some of them.
VOR (omnidirectional radio range) and DME (distance measuring equipment) are often located at the same site. They operate on VHF (very high frequency) and UHF (ultra high frequency) respectively and are not affected by static or other interferences. The maximum range of VOR is about 200 nautical miles. By flying VOR the pilot ensures he is flying directly to the station. Also by measuring radials from more than one VOR station, a pilot can check his position.
The function of DME is to measure distance. The DME measures, electronically, the time it takes for a signal, transmitted from an aircraft interrogator, to reach the ground base station transponder, and return. This elapsed time is converted to miles and appears on a digital indicator on the flight deck. The indicator actually seems to rapidly count the number of miles between the aircraft and the station giving the pilot a continuous digital reading of how far he is from or to a station.
With the many VOR/DME stations along the route, a pilot can make good his desired track; is constantly aware of his distance to or from a DME station; or, by using two VOR radials, establish his exact position.
ILS (INSTRUMENT LANDING SYSTEM)
The ILS is designed to provide an approach path for exact alignment and descent of an aircraft on final approach to a runway.
The ground equipment consists of two highly directional transmitting systems along with three (or fewer) marker beacons. The directional transmitters are known as the localizer and glide path transmitters.
The system may be divided functionally into three parts: guidance information – localizer, glidepath Range information – marker beacons, Visual information – approach lights, touchdown and centerline lights, runway lights.
1. The localizer transmitter, operating on one of the twenty ILS channels emits signals which provide the pilot with course guidance to the runway centerline.
2. The UHF (ultra high frequency) glidepath transmitter, operating on one of the twenty ILS channels radiates the signals principally in the direction of the final approach.
3. Ordinarily, there are two marker beacons associated with an ILS; the outer marker and middle marker. However, some locations may employ a third beacon – the inner marker.
The outer marker normally indicates a position at which an aircraft at the appropriate altitude on the localizer course will intercept the ILS glide path.
The middle marker indicates a position at which an aircraft is approximately 3500 feet from the landing threshold. This will also be the position at which an aircraft on the glidepath will be at an altitude of approximately 200 feet above the elevation of the touchdown zone.
The inner marker, where installed, will indicate a point at which an aircraft is at a designated decision height on the glidepath between the middle marker and landing threshold.
The principles of radar are not new: in fact, some early experiments were made back in 1880s. In 1904 a German engineer had invented, as he explained, a “radio-echo collision prevention device”
The word “radar” was originally derived from the descriptive phrase “Radio Detection and Ranging”.
The application of radar in the air traffic control system consists of two basic designs. The initial type of radar, called primary radar, began to be used for advanced air traffic control. When the word “radar” is used alone it usually includes both primary and secondary radar.
There are three additional forms associated with primary and secondary radar:
Radar Echo – the visual indication on display of a radar signal transmitted from an object.
Radar Response – the visual indication on display of a radar signal transmitted from an object in reply to an interrogation.
Radar Blip – the collective term meaning either echo or response.
In primary radar a beam of individual pulses of energy is transmitted from the ground equipment. These pulses hit the aircraft from 16 to 34 times each scan. An aircraft in the path of this radar beam will reflect back some of the pulses which are picked up by a receiver. This reflected energy produces a bright “echo” or “target” on a cathode ray tube.
SECONDARY SURVEILLANCE RADAR (SSR)
The SSR system provides for six modes; only two modes are used in civil aviation:
Mode A for civil and military identification.
Mode C for automatic pressure altitude information.
The SSR is a valuable tool for automatically identifying aircraft. Identification is achieved by providing the controller with a specific radar beacon target identity of aircraft. A total of 4096 discrete reply codes are available for special position identification to be transmitted on request of a controller.
With SSR display, the controller sees aircraft returns on his PPI (plan position indicator) as two slashes, clearly distinguishing them from primary targets which are single blips.
In modern systems different synthetic symbols are used to indicate a lot of additional information.
VISUAL AIDS FOR NAVIGATION
Additional visual aids to navigation consist of markings on the aerodromes. These markings comprise single lines or rows of lines which, for the pilot, are very important for holding positions, runway thresholds, the runway centre lines, the sides of the runways, etc.
However, at night or during poor visibility by day, lights are required. To be effective lights must be of adequate intensity. At certain aerodromes the controller can vary the intensity of some of the lights so that they can be reduced not to blind the pilot and strong enough so that he can see them in bad weather.
The first lights a pilot sees on approach is generally the aerodrome beacon. It may rotate and can be seen at a great distance. There might be an identification beacon which shows green flashes of light. Red lights, the usual danger signal, warn pilots of the obstacles such as hangars and other high buildings, telephone poles, etc. Runway edge lights identify the runway and approach lights assist the pilot to align himself with the runway.
Lights may also be used to provide a glidepath similar to what an ILS provide electronically. The Visual Approach Slope Indicator System (VASIS) is a beam of light having a white colour in its upper part and a red colour in its lower part. A pilot of an aeroplane during an approach will:
a) when above the approach slope, see the lights to be white in colour;
b) when on the approach slope, see the lights to be pink in colour; and
c) when below the approach slope, see the lights to be red in colour.
By reference to VASIS, combined with ILS, the pilot can bring an aircraft down safely almost to touchdown by day or night.
After landing, he follows the blue taxi lights along the taxiway to the apron and the service areas.
At the service area a marshaller, with illuminated wands, directs the aircraft with signals to its proper position for unloading and, finally, signals pilot to cut the engines.
There are airports in every country. In theory, an aircraft can fly an infinite number of paths through the air from any surface point to any other. In practice, paths of flights lead from airport to airport. As a rule the airport is to be situated not far from the city. If it is a long way to the airport there is special bus service to take passengers from the city Agency to the airport.
Aircraft not only need proper landing and take off facilities. Moreover, those who use aircraft need services and accommodations which the airport must provide. The modern airport is a complex structure, a centre of most diversified services. Millions of passengers and thousands of tons of air freight are handled by modern airports. Thousands of people are working at airports.
Any airport can be divided into main parts: the landing area (runways and taxiways) and the terminal area (aprons, buildings, car parking areas, hangars etc.). The number of runways, their length and location depend on the volume and character of traffic, the prevailing wind directions and other factors.
The runways and taxiways should be arranged so that to prevent delays on landing, taxying and take off operations.
Aprons are required for aircraft to make final checks prior to departure. The main function of the terminal buildings is to handle departing and arriving passengers and their baggage. In the reception halls at the check-in desks passengers register their tickets, their suitcases are weighed and labelled here too. Baggage check-in facilities utilize conveyors to move baggage without delays.
In the terminal there is an electronic flight information board to list departure and arrival times. If any delay takes place such information is also indicated on the board.
The airport has to maintain a number of supplementary services. There must be an airport clinic, fire brigade, special vehicles and equipment units (water and catering trucks, tow tractors, refuellers, etc.).
Other services include maintenance, overhaul and repair of stationary and mobile equipment, the supply of electricity, water, heat and air conditioning.
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.
Nowadays there exists one more pressing problem – that of air piracy. Now every airport has new specific detection systems capable to screen passengers and their baggage, cargo parcels and mail.
Emergency is a serious event that needs immediate action. The type of emergency that may occur is completely unpredictable. No official documents examine the classification of emergencies. Each of them is an event on its own. It may be similar to other emergencies, but it is rare to have two which are identical in every respect. The exception to this for working radar controllers is a mid-air explosion, and although the actual cause of the explosion might well differ, its effect on the controller will be the same.
It is impossible to define instructions for all cases and write such a document as phraseology for emergencies. Nevertheless there are some standard procedures which help to prevent chaos and make controller’s work organized and regulated. Some types of emergencies have specific instructions as to the actions which the pilot and ATC controller must make.
An aircraft under emergency gets priority over other aircraft. There exist instructions concerning using special radiotelephony signals. Pilots must inform ATC by sending established signals (May Day, PAN, Securite) and the controller must impose silence.
There are certain actions which are common to a controller handling of all occurrences.
1. Don’t keep it to yourself.
2. Get help. And get it early enough to be of practical value.
3. Inform your supervisor. In most cases he will be able to do most of the liaison which will be needed.
4. Do not forget your other traffic. It may become necessary to transfer all traffic except the emergency flight to another frequency. The whole of the air traffic team on duty will be very busy to provide the best possible service to the flight in the difficulty. Emergencies are where all of the controllers training and expertise are vital.
5. Keep calm. Never let your voice portray nervousness or unease.
Sometimes the controller does not fully understand what the precise problem is. That’s why a controller (as well as a pilot) must know not only radiotelephony phraseology but also possess knowledge of the general English. Reading aviation magazines and accident reports can greatly help to understand problems which may occur.