I have attached a screenshot of a flight plan for EHAM to LEMD. This is a flight to the west yet the assigned altitude was 31,000. This is an incorrect ODD number for a westerly flight and unusually low for this aircraft and distance. Later I tried a flight plan from LEMD to LIML and it assigned an EVEN number.
Hello,
So Simbrief is actually performing correctly here. Under ICAO rules, E/W=000-179° and 180-359°.
However, there are a number of countries, including France, Spain, Italy and Portugal who use a North/South orientation instead.
- 090-269 → Odd
- 270-089 → Even
Your EHAM to LEMD flight runs almost entirely through French and Spanish airspace, both of which use the North/South rule, the track being 200-210° which falls into the southbound/odd half so FL310 is correct.
Regarding the altitude, FL310 is only the initial cruise portion, your particular flightplan included step climbs to FL390 (which isn’t shown in the screenshot). FL310 was what the route optimizer selected, (weights/CI and upper winds taken into account).
Thanks for taking the time to help me understand. This is why Navigraph is such a great resource!
Scott