Not wanting to nitpick at G CEXO's answer, because its perfectly correct, I think he meant flying an "Even" flight level when he said "positive" flight level.
Hopefully ALL flights levels are "positive"...
Magnetic track=
0 - 89 : Odd thousands of feet (FL30, FL50)
90 - 179 : Odd thousands + 500 ft (FL35, FL55)
180 - 269 : Even thousands of feet (FL40, FL 60)
270 - 359 : Even thousands + 500 ft (FL45, FL65)
Last edited by beatnik; 21st May 2012 at 00:23.