They may fluctuate, however they always fall back to the mean trim speed with no intervention. It's ground speed that fluxuates, not airspeed. Ground speed is only relevant at the moment of touch down, and you adjust for that in the flare.
If the person in DC wants to go up, I'll gladly demonstrate.
Ah, now reality has almost been restored. Yes, we trim to an airspeed, and, barring disturbances, the plane will fly that airspeed.
However, the disturbances in normal conditions here induce fluctuations from 5 to 10 knots, and it is most certainly indicated AIRspeed that is fluctuating, as well as ground speed.
Now, we can start a new discussion of how much of that is instrument error due to pitot placement, or any of a wide range of possible influences on what your airspeed indicator is displaying, but it is most certainly displaying a variance of from 5 to 10 knots at various points.
I just landed and verified this. We have a significant gulf breeze this evening (which is totally normal). As I slid down final, my airspeed varied from 72 to 77 knots, as I adjusted for the changing wind, which was extremely smooth (again, very normal here; it can be whistling at 30 knots, yet still be perfectly smooth, thanks to that wind not having hit any obstacles for 800 miles) but varied with altitude.
Once I've got the landing assured, my eyes are outside, so I don't know my touchdown speed, but it was smooth and with a very short rollout. (The RV-8A is an absolutely simple plane to land well. The only planes I've flown that landed easier were King Airs and an Ercoupes...)
Sorry, OP -- didn't mean to hijack your thread!