wierd feeling
 

ever stand in line with someone to close to you in the behind position and feel little bumps? the last two flight at low power setting (mp25,rpm24) at 5000k indicating 140 (cruise descent for landing)the feeling starts. no indication on any guage, just the constant little pushing from behind. cobb up to 170-160 indicated and it goes away. anyone have any suggestion what to look for or what is causing it. gear doors up, recycled cowls numerous times, there is no indications on flight controlls (like when bolts on control surfaces get slightly grooved). this takes the fun out
flying and would like to solve it. rick

Rick , at 140K indicated, I don't think it's the tail booms. What model are you flying? T or P or normal - what version?

it is a 1973 p337 reims with only 1500 hrs. just went out and look at the a/c and noticed small amounts of oil on the outside of the back prop (just a trace maybe 6" spread from the spinner out)
could the prop be changing pitch and not show up on the rpm guage or the sync. meter? could small amounts of pitch change cause the slight bump feeling? the props were overhauled 24 months ago when we put new engine in and have only accumilated around 175 hrs.

Hi, Rick.

I have been flying aroung a lot lately at 100 to 120K working on my Instrument rating (120 to 140 mph on my '67 337B).

A while back, I noticed a slight bumping (shudder?), but neither of my cfi's could really feel it. I dropped a notch of flaps, and the bumping went away.

I have discussed this with my mechanic and he suggested that it may wll be just a slower airspeed/mp/rpm setting than I am used to... but I am not so sure.

I am more aware than before, but do not experience it above about 140 mph.

This probably doesn't help, but my hackles just went up a notch.

Jim