I've heard that SF officers can still go out in the field quite a bit, until they hit Captain. After that, their time will shift more and more towards management duties. I've also heard that OSI has a 75:25 split between office and field work (supposedly fairly steady, but that is 3rd hand knowledge).
LOL...the pilots I fly with put about eight hours behind a desk for every one they fly. Flying isn't just about strapping a plane to your but and rocketing down the runway to defeat evil.
Very few jobs will not put you behind a desk every week. It is a fact of being an officer. You are a leader, not a worker.
Even "pure" research jobs entail report writing, attending meetings, and all kinds of "non-productive" time. As you acquire more rank--either officer or enlisted--the more time you'll spend operating a desk.
There's nothing set in stone but once you make 0-4 you will be expected to fly the desks more. I'm pretty sure that rated types can still keep the flight pay as long as they maintain minimum proficiency...there was a movement years ago to have a distinct "flying track" whereby you'd bypass the administrative billets that come about as you rise in rank. Don't think it "flew" (sorry - couldn't resist).
Caninedale's 8-1 ratio sounds generous in fighters. If you figure (non desk time of) 20-50 minutes to brief each sortie, then 20 minutes to gear up, step to the jet and do preflight checks, flying a 2-hour ride from gear up to gear down, then 15-40 minutes to debrief the flight - it makes for a long day.
I would agree with MSgt Stengle that it seems 0-4 is typically the rank when one is slapped with a (usually non-flying) staff job.
The only two actual "jobs" I could think of that fly more and have less paperwork than others are both already experienced wingmen pilots (can fly in crappy weather and night rides) and are Lieutenant slots - the Snacko and the Navigation officer.