Air transportation is the carriage of passengers, mail and freight by aircraft or helicopters. All air transportations are classified according to the territorial sign, to the objects of transportation and to the direction of transportation.
By the territorial division they are defined as domestic and international flights. Domestic and international flights are divided into schedule and non-schedule flights. Schedule flights are performed according to definite traffic schedule. Non-schedule flights are operated in accordance with special agreements and orders. On international routes they are known as charter flights.
Depending upon the object of transportation we define passenger, mail, load and freight flights.
As to their direction the flights differ as non-stopover flights, that is from the point of departure to the point of destination; round trips, from the point of departure to the point of destination and back to the starting point; and onward journey with the transfer from one airplane to another.
22.2 Convective storms. Why are they dangerous?
Hazardous conditions created by bad weather develop many components of the aviation weather system. For flight operations in the terminal area, including airports, the main threats include microbursts and low-level windshear, severe turbulence, lightning, and hazardous levels of precipitation (extremely heavy rain, large hail). In the en-route environment, convective storms can create regions of severe turbulence.
The term convective storms covers a wide range of possible storm phenomena, which range from rain, hail or drizzle to cold fronts or snow showers. Convective storms seriously disrupt ATC operations, especially in terminal control area (TMA) and airport environments. The major problems created by convective storms are delays, diversions, and cancellations when airport operations are curtailed. Accurately forecasting the appearance of convective weather is a major challenge facing the meteorological community.
23.2 Is it necessary for air traffic controllers to possess a medical certificate?
Medical certification is obligatory for all air traffic controllers notwithstanding whether they are operating or on other duties. They have to undergo it every three years.
They should be examined as often as possible to avoid different problems that could influence their performance. Medical examination is usually provided by air navigation services providers and air traffic controllers donít have to pay for it.
∑ The evaluation of medical fitness must be based on a medical examination conducted in accordance with the highest standards of medical practice.
∑ Individual air traffic controllers ought to consult their Aeromedical Examiners for advice regarding the likely impact of illness or medication on their fitness to provide air control services.
∑ Air traffic controllers who are under forty donít have to renew their medical certificate annually but once every two years.
∑ An application for a medical Assessment issues in accordance with the procedure shall undergo a medical examination based on the following requirements: physical and mental state, visual and colour perception, and hearing.
24. 2 How does lightning strike affect an aircraft?
A flash of lightning is a very dangerous phenomenon for any aircraft in the air. When an aircraft encounters front thunderstorm, it would better avoid it, otherwise the consequences can be unpredictable. In this case very strong electrical current appears in the electric circuit (both primary and secondary). It also can cause total electrical failure, after that an aircraft becomes uncontrollable and as a result there might be a crash.
25.2 What is a bird strike?
An aircraft hitting a bird may create an emergency situation, known as Bird strike. The seriousness of this emergency depends on:
∑ the size of the bird;
∑ the speed of the aircraft on impact;
∑ the place it hits the aircraft;
∑ the phase of flight.
It effects may be very severe. The most dangerous strikes are to the windshield and engine.
Windshield cracked may result in possible flight crew injuries or death, flight control problems, forced or emergency landing.
A strike of this nature may lead to the ultimate loss of the aircraft. Strikes both in windshield and engine may impair the flying characteristics of the aircraft, making levels and heading difficult to maintain and safe landing difficult. They may ultimately lead to loss of control or even structure failure.
Bird ingestion generally happens when an aircraft encounters a big flock of small birds like owls, crows, ducks, seagulls. As a result an engine flame-out, ditching, rough or emergency landings are possible.
The bird strike might be very dangerous above all to aircraft flying at low altitudes.
The greatest risk of a bird strike is below 1,000 feet, with decreasing risk between 1,000 feet and 5,000 feet. The danger above 5,000 feet is much less but there is still some risk from migrating geese or other large birds, which have been encountered above 20,000 feet.
Generally the worst cases are impacts with big birds like vultures, eagles, falcons.