[Uncle Chip]

That area was an international flight path that hundreds of planes were still using on the day of the shootdown — and the Russians knew it and should have warned their BUK commanders accordingly as if they didn’t know already.

[FR_addict]

Many airlines were avoiding the area. USA airlines were told not to use it. Qantas and Cathay Pacific also quit flying the route.

Malaysian Air Flight Took Route Avoided by Qantas, Asiana

http://www.bloomberg.com/news/2014-07-18/malaysian-airline-took-flight-route-avoided-by-qantas-asiana.html

The Ukrainians and Eurocontrol would absolutely know that there had been planes shot down in the area in the last week. Yet, they did not restrict the area until after the plane was downed.