How to turn over large number of items halfway through baking oven
Yes, it is supposed to be a 180 degree flip, you want both sides to be heated evenly. 

If you are using a flat or low-rimmed baking sheet, and have a second one the same size: oil the second sheet with only a very thin layer of oil. Take the first sheet outside, cover with the first. Grasp at the two sides, flip both sheets with the food sandwiched between them. Bake in the second sheet (which is now on the bottom). 

Of course, this has its downsides too. You cannot use baking sheets with too high a rim (else the food will slide inside too much), you have a second sheet to clean, and there is the danger of burning yourself while you wave a hot baking sheet around. But especially for large amounts of food, or multiple batches which are done in two sheets anyway, it might be less hassle than turning with a spatula.