Something I’ve been wondering–why is the American flag patch backwards on military fatigues?
It’s not. I’ve read where it’s supposed to look like it’s flowing backward, away from a soldier as he’s running.
American Flag Patches - Why Are Some Backwards?
Why is US flag printed in reverse on US airplanes?
Why is the flag reversed on uniforms?
why is one US flag patch backwards on mil uniforms?
Backward flags on US soldiers?
Backwards flags on troops shoulders-why?
Heh: 
American Flag Patches - Why Are Some Backwards?
Why is the flag reversed on uniforms?
why is one US flag patch backwards on mil uniforms?
Backwards flags on troops shoulders-why?
Ranger backward flag patches
Backwards flag on US uniforms
On preview: dang it!
Note that the same rule applies for a flag on the side of a self-propelled (not wind-propelled) vehicle. Basically, it’s the same way that a real cloth flag would fly, were it attached to a pole on the moving thing. Note also that this means that a flag on the left shoulder of a uniform, or on the left side of a vehicle, would appear normal.
These customs are true not just for the US flag but for nearly all flags that aren’t vertically symmetrical. (I believe flags that have writing on them, like the Saudi Arabian flag, are never displayed “backwards”.)
For that matter, it’s not just about flags - the US Postal Service emblem with the eagle has also traditionally been painted “backwards” on one side of postal vehicles, so it would look like the eagle was always flying forwards.
The real answer to your question is that there is no such thing as a “backwards” American flag. When you are walking past a flag on a flagpole do you wonder why it’s backward on one side and not on the other?