I don't know about any official maximum amount of precession, but 10 degrees
in 10 minutes during mostly straight and level flight would be beyond my
tolerance for safely in instrument flying.

"Jay Moreland" wrote in message
...
I need to find out if there is an official maximum amount of precession
for a Directional Gyro. My aircraft precesses 10 degrees in 10 minutes
during mostly straight and level flight with only a few shallow banks.

One avionics tech told me that it depends on the gyro manufacturer as to
what is acceptable. He also told me that an out of the box unit tested
on the table should not precess more than ONE degree in four minutes.

Jay Moreland