Can I fly with a fountain pen?

A pressurised aircraft cabin can cause air in the ink chamber of a fountain pen to expand, expelling ink from the nib. This ink can get on the inside of the cap and in turn on the gripping section. In extreme cases the pen will "burp" a large blob of ink. The cure for this problem is to either completely empty or completely fill your pens prior to flying. Do not use your fountain pen during a flight, just in case.