by OTTOL » Fri Jan 14, 2005 11:23 pm
As Nexus stated, the rules that apply for 2,000' separation above FL 290, will be history in five more days. Just for nostalgia sake though......under the current system.....about %99 of the traffic adheres to the rules of direction vs altitude. Exceptions will be: traffic traveling on North/South headings, airways that transition from Easterly to Westerly headings or vice versa (the airways between New York metro and South Florida are a prime example, with the bend at Jacksonville), when an aircraft makes a request for it or when ATC assigns it. A common circumstance is when an aircraft requests to climb 2,000 feet for weather avoidance, to avoid turbulence or to decrease fuel burn. The request will be made for "wrong direction" flight level. ie:"United's 556 reguests wrong direction flight level four one zero". The more commonly heard syntax is..."any chance, wrong direction four one zero, United's 556" and this more common version of appeal has to do with the fact that it is other than standard and also because it's usually needed to get out of one of the previously mentioned predicaments.
As far as a "cruise clearance", I've never heard of one being assigned in Class "A" or PCA airspace. A "block" altitude is pretty common though and will encompass 2,000 feet from sea level to FL290 and 4,000 feet between 290 and 600.
I've done some flying in Europe and flown across the Atlantic many times and can say that the directional rule is used. At present the rule that applies in the US in class "A"(PCA) airspace is as follows; 360-179 degrees will be flown at odd altitudes and 180-359 degrees at even altitudes. Starting at FL 290, 2,000 foot intervals are used, so that 360-179 degrees, becomes flight levels 290,330,370,410,450.....and flight levels 310,350,390,430.....are used when flying 180-359degrees. When RVSM becomes a reality, the rules that apply from flight levels 180-290 will then apply for altitudes up to FL600. So, the same situation may occur, with the difference now being only 1,000 feet I think that "wrong direction" will become a memory.
Last edited by
OTTOL on Fri Jan 14, 2005 11:25 pm, edited 1 time in total.
.....so I loaded up the plane and moved to Middle-EEEE..........OIL..that is......