Originally Posted by
ATC Watcher
Ian W and Air Scotia :
Maybe in the USA where there is an old " CB avoidance" culture and ATFM ( Flow management) organised through a single command centre which has direct access to the US Air Force areas .
Europe is also equipped with an advanced centralized ATFM system , but does not have the same weather pattern as in the equator/tropics or continental US. and there are 40+ airforces around to deal with.
A totally different picture that what is going on the rest of the world unfortunately , and definitively in South East Asia , where each Sate has its own air force and where countries are suspicious of one another and do not cooperate.
ATC is there to separate aircraft from one another also aircraft from penetrating reserved or restricted areas, and to comply with restrictions and demands made by teh next sectors( control centres) .
There is no standard " Miles in trail " separation applied by all. They vary depending on location and surveillance capabilities. , it can be 5 NM . can be 100 Miles (15 minutes) . It can be 5 NM in one sector , and 10 minutes at the transfer point for the next sector in a different Control Centre no equipped with same capabilities. Once established controllers have to follow that.
But, once again , the pilot has the decision on weather avoidance, not ATC . The pilot(s) can see in real time what the actual weather is , ATC cannot. If a request for deviation ( laterally or vertical ) cannot be approved by ATC ( due e.g. restricted or dangerous areas penetration or simply other traffic ) the PIC can deviate on his own bu just declaring on the R/T , " unable, turning or climbing now ". This then becomes an emergency situation , and ATC will help clearing the way. The PIC is always ultimately responsible for the safety of his flight.
To come back to this Air Asia case, I have seen no indication so far that the Pilot of this flight did not jut do that, but he did not tell ATC, so for me I think there must be something else, or the initial request to deviate came much too late.
I will pick up a few points from what you say:
Yes FAA, NAV Canada, and the Member States of ECAC - EUROCONTROL, Air Services Australia have fully fledged Traffic Flow Management (TFM) Systems. Under ICAO coordinated flow management is being developed with GREPECAS, the states of Caribbean and South America. The Asian Pacific Region Air Navigation Service Providers (ANSP) are aware that they do not have a networked TFM system and work is in hand using the auspices of ICAO to put one in place (see
http://www.icao.int/APAC/Meetings/20...attachment.pdf )
Miles/Minutes in trail are going to be different as the aircraft moves from surveillance based control to non-radar procedural time based control. In consequence the flow management at boundaries between these sectors becomes complex. As surveillance based control normal separation minima are considerably smaller than procedural.
The statement "
The pilot(s) can see in real time what the actual weather is , ATC cannot." is not necessarily correct - and even if true it is too simplistic to just avoid the next heavy rain radar return. Both the pilot and the controller may be able to see weather, their systems are different so they will see different weather. The controller can also see a lot further ahead and can see sucker traps where some flight paths would lead into dead ends, the controller also may have had lots of PIREPS on turbulence. The controller's weather comes from different radars so it will present weather information that is hidden from the aircraft radar by attenuation. It makes real sense for both the controllers and the pilots to work together there is no competition, both want the same outcome and the pilot should accept any help that can be offered.
If the weather is getting a bit too exciting then the pilot should say so
early don't wait till things are really bad or until ATC gives you an instruction you can't take. If you can tell the controller that the weather is looking really bad ahead of you or to one side and you may need to take some avoiding action, then the controller will start ensuring that other traffic is kept clear of both you and the weather you are reporting.
The time for 'Communicate' is before things get so bad that all you can do is 'Aviate' then perhaps things won't get to that stage.