At weighing that the derivative pandemia of the Covid19 has produced a drastic descent of the daily number of flights at world level, at a day can give thousands of simultaneous flights. In fact, in July of 2019 it reached achieve the figure of 230.000 at only day. The management of the aerial trance at precise world level of some determinate procedures that permit to standardise all the operation of flight since the takeoff at the flight of cruise, or the landing.
How it orders the aerial trance?
The Organisation of International Civil Aviation (OACI) determined at the International Agreement signed in Chicago at 1944 that the world airspace would be divided at nine Regions of Information of Flight or FIR (Flight Information Region). These regions do not correspond exactly with the borders of the countries, and subdivide at regions or FIR smaller. Like this, for example, Spain forms part of the FIR European, that at his turn is conformed by other FIR smaller. In Spain concretely exist three regions: Madrid, Barcelona and Canaries.
Attended that the aerial navigation produces in a three-dimensional field, where the rooms divide no only on the terrain but also at the tall, it is necessary to establish divisions also at height. Vertically, the Regions of Information of Flight divide at:
- FIR: Distance that there is since the soil until the 24.500 feet or 7’5km roughly
- UIR (Upper Information Region): Distance among the 24.500 feet until the 46.000 feet, some 14 km roughly.
Among the 33.000 and the 42.000 feet of altitude, is the strip where the trading flights habitually situate at flight of cruise, since here find a minor resistance of the air for the fact that is less dense, which thing permits to consume less fuel and travel faster. For the fact that at these altitudes is very important that the relative distance among aircraft was very precise, the aircraft travel at what meets as a “levels of flight”. For this all the airliners, from a determinate altitude, regulate his altímetros at the pressure nicknamed “standard” (1.013 milibares) -independently of the barometric pressure that marked the altímetro at his respective places of start- for like this eschew dangerous discrepancies. Like this, we find us that an airliner that split among one borrasca with an atmospheric pressure very low and that is blasting at level 3-6-0 (36.000 feet) will be parted exactly 3.000 feet of another that blasts at level 3-3-0 (33.000 feet), but that elevated among an anticyclone with pressures of the order of the 1.040 milibars.
To correct what at the previous phases of the landing or immediate after the takeoff would be a problem, after crossing at descent or ascent a determinate level nicknamed “level of transition” effect the corresponding corrections at the altímetro, already was calant the pressure standard (at ascent) or the pressure (QNH) signified by the tower of corresponding control at the airport of fate.
During the flight, the aircraft cross distinct zones of control at which subdivide the FIR and the UIR. Since the most immediate at the airfield; the zone of control of trance (ATZ) of some 5 nautical miles around the area of flights; the CTR, or Airspace Controlled, that embraces some 12 miles; until the TMA, or Terminal Area, that extends sometimes for hundreds of miles around the big airport Hubs and where conflueix the trance of the aerovías that cross the FIR. Complicated, no? Then,
Who manages the aerial trance?
The persons that manage, schedule, order and direct the aerial trance are the aerial controllers, or ATC (Air Transit Controller, for his acronyms at English). The ATC organise of this form:
- Torreros: those attendants to control the circulation of the aircraft on shore during the shooting until the pitch at kick, and authorise the takeoffs and landings.
- Controllers of approach: Quan the control of Tower transfers the “trance” (airliner) after the takeoff, the Control of Approach commissions to guide the “start” to the path that the airliner will have to track. Also they are the attendants to order the trance that directs at the airport to land, ordering it at height and course so as to achieve a fast and certain operation.
- Controllers of path: they manage the communication with the pilots at height during the flight. They are the attendants to authorise or denegar at function of the trance or of the atmospheric conditions the changes of “level of flight”, changes of path and maintain the suitable vertical separation and horizontal among the distinct trances.
How much work! Fortunately each airspace divides at “sectors” smaller, that make handier the bulk of work of the ATC. At a sector of approach at an airport like the of Barcelona, the controller can reach manage until a dozen of trances simultaneously. The controllers at the moments of more trance relieve each two hours, with half hour of rest among intervals, so as to eschew the stress.
One of the labors of the controllers is to maintain at the airliners with the sufficient room among them to eschew possible collisions. Therefore, they exist some parameters of specific distance for each moment of the flight.
At the air: horizontal minimal Distance among two airliners that blast at the same height is of five nautical miles (9 km roughly). For the that respects at the vertical separation, can not inferior being at 1.000 feet (300 metres roughly).
At takeoff: Time among aircraft will depend of the weight of the aircraft, and therefore of the turbulent trail that generates after if. In general, among takeoff and takeoff uses to let a room of time of some two minutes. Nevertheless, if it does not exist wind that dissipate the trail or the aircraft precedent is much more weighed that what will elevate in the second place, among takeoff and takeoff can reach mediate until 10 minutes
At the following image can observe a digest on the order that have to maintain the airliners at the air.
Meet which is the country with main aerial trance? Although it have decrescut for the crisis of the Covid19, the United States wears the record with main number of aerial passengers at the world. Have more information here.