Monday, November 22, 2010

Does the Magnetic Compass have an inspection?

One of my favorite parts of being a flight instructor is all that I learn when I go flying or just hang out with other pilots. The other day someone asked me how often does the Magnetic Compass need to be inspected and  I had no idea. After trying to find the answer online, I didn't get what I was looking for until....I asked a mechaninc. He referenced me to Part 23 (airworthiness standards) and it says that when flying under Part 91

§ 23.1547   Magnetic direction indicator.

(a) A placard meeting the requirements of this section must be installed on or near the magnetic direction indicator.

(b) The placard must show the calibration of the instrument in level flight with the engines operating.

(c) The placard must state whether the calibration was made with radio receivers on or off.

(d) Each calibration reading must be in terms of magnetic headings in not more than 30 degree increments.

(e) If a magnetic nonstabilized direction indicator can have a deviation of more than 10 degrees caused by the operation of electrical equipment, the placard must state which electrical loads, or combination of loads, would cause a deviation of more than 10 degrees when turned on.

There is no required time to recheck the correction though it is strongly suggested that it be recalibrated after installation of new equipment.

I am very grateful to work somewhere where the mechanics are both good at their job and helpful when I ask my questions.