The idiomatic expression "adjustment on the fly" means making a change or adjusting something quickly and without preparation, while in motion. Full definition
You now only need to swipe down once to pull up the brightness bar and make adjustments on the fly whenever your S8's brightness isn't to your liking. (android.gadgethacks.com)
You now only need to swipe down once to pull up the brightness bar adjustment on the fly whenever your S8's screen is either too dark or too bright. (android.gadgethacks.com)
For example, by maintaining a two - way information flow with his customers he can make critical adjustments on the fly. (inc.com)