The aircraft marshallers are responsible for directing by visual or other means the movement of aircraft on the ground to its parking, hovering and landing place and for the pushback, and the towing of aircraft on the ramp and taxiways.
Runways are generally designated according to their magnetic heading (the takeoff direction that it is "pointing towards"). Runway's designation is not written in degrees, but is encoded in the whole number nearest one-tenth (degrees divided by 10 rounded) of the magnetic azimuth of the runway centerline, measured clockwise from the magnetic variation. As a runway has two ends for take offs and landings, it therefore has two designations.
Take Macau International Airport as an example, its runway designations are "16" and "34".
Runway 16: 163/10 => 16.3 => 16 (rounded)
Runway 34: 343/10 => 34.3 => 34 (rounded)
A flight recorder, colloquially known as a black box, is an electronic recording device placed in an aircraft for the purpose of facilitating the investigation of aviation accidents and incidents. It is located at the aft of the aircraft where it is more likely to survive an accident.
Although it is commonly named as the black box, it is bright orange in colour which is intended for high visibility in wreckage. During the period 1940-1945, new electronic innovations were added to aircraft on a regular basis. The prototypes were roughly covered in hand-made metal boxes, painted black to prevent reflections. After a time any piece of "new" electronics was referred to as the "black-box".
A flight recorder contains two components: a flight data recorder (FDR) and a cockpit voice recorder (CVR).
Flight data recorder (FDR): an electronic device employed to record instructions sent to any electronic systems on an aircraft. It records significant flight parameters, including the control and actuator positions, engine information, altitude, airspeed and heading, and time of day and so on.
Cockpit voice recorder: an electronic device used to record the audio environment in the flight deck of an aircraft, including conversation in the cockpit, radio communications between the cockpit crew and others (including communication with air traffic control personnel), as well as ambient sounds and engine noises.
The economy class syndrome (deep vein thrombosis) is directly related to immobility for long periods during which blood pools in the legs, raising the risk of clot formation, occurring during (or just after) a long airplane flight, especially in economy class (tourist class) where there is the least space allotted per passenger. The tendency to immobility is often compounded by the fasten-seat belt sign, the presence of carts in the aisles, etc. In serious cases, the blood clots may be carried to the lungs and block the veins leading to difficulty in breathing or even dealth.
Other risk factors contributing to the syndrome include lower oxygen pressure and dehydration. Changes in oxygen pressure in the cabin tend to decrease the oxygen level in the blood. The air in the cabin lacks the normal degree of humidity which contributes to dehydration. The serving of coffee, tea, and alcoholic beverages (all of which are diuretics) further causes passengers to become dehydrated.
The economy class syndrome is not confined to that class on a plane. It is recommended that all persons traveling on air flights, irrespective of which class they are in, drink lots of water and move their legs by walking whenever possible and by periodically flexing and extending their ankles, knees, and hips to minimize the risk of economy class syndrome.