Marty from Sunny Florida wrote:
Hey everyone.

I have a C152 with good vaccuum, but the Directional Gyro precesses at an
abnormally high rate. What's the prognosis? Can it be fixed, or just
replaced? What can I expect to pay for a new DG?

Before you spring for a new HI be sure you aren't just seeing a magnetic compass
in need of swinging. Align the HI with a published, known heading from
airnav.com or from the A/FD. Fly around for a bit *without* resetting the HI to
the mag compass. Return to the same runway and check it again. If it's still
correct, have your magnetic compass swung. If not, replace the HI or look for
some reason the HI's not performing correctly. Got vacuum?

Anyway, my main point is that a magnetic compass in need of swinging can look
like HI precession.