Although German air defence over the Warsaw area itself was almost non-existent , about 12 % of the 296 planes taking part in the operations were lost because they had to fly 1,600 km out and the same distance back over heavily defended enemy territory ( 112 out of 637 Polish and 133 out of 735 British and South African airmen were shot down ) .
Although there was almost no German air defence over the Warsaw area , about 12 % of the 296 planes were lost because they had to fly 1,600 km out and the same distance back over heavily defended enemy territory ( 112 out of 637 Polish and 133 out of 735 British and South African airmen were shot down ) .