"Wrong Way" Altitudes for IFR

The Canadian Aviation Regulations are quite specific on the subject of altitudes appropriate for direction of flight. For an eastbound flight (defined as any flight with a magnetic track between 000 and 179°), the IFR pilot should be flying at an altitude which is an odd number of thousands. 3,000, 5,000, 7,000, FL190, FL230, etc. For a westbound flight (180-359°), it should be an even number of thousands, like 4,000, 8,000, FL200 etc. This extends into RVSM airspace as well, up to FL410. Above that, it's two thousand feet between levels. Another topic, maybe?

There arise occasions where a flight needs an inappropriate altitude. For example, a Dash 8 riding the turbulent tops of cloud at FL240 may request FL250, since the service ceiling with passengers is FL250 and therefore FL260, the next appropriate altitude, is not available. In controlled airspace, ATC may assign altitudes inappropriate to the direction of flight under certain conditions. First, the reason for the request must be given by the pilot, and it must be because of icing, turbulence or fuel considerations. Additionally, a pilot who is flight checking a NAVAID, holding on a fix, or in training may get approval for this. Medevac flights may receive a clearance for an inappropriate altitude, as well. One of the things ATC is supposed to do, to toe the line with CARs, is to ask the pilot when fight at an appropriate altitude can be resumed. This may be difficult, since it is rarely known how long the conditions requiring the altitude will extend. A best guess should be provided to ATC, and controllers should be understanding that it may not be as stated in the end. As soon as it is practicable, the pilot should request a clearance back to an appropriate altitde.