I used to carry a Parker 51. I'll never let that pen go, but like many fountain pens it was too risky to take on a plane. Pressurized cabins seem the perfect environment to cause a leak. I've tried and tried but many a jacket or shirt pocket bear the stains of my forgetfulness.
Several years ago, I found the Pilot Vanishing Point fountain pen. It is a well-balanced and well-sealing writing instrument that has never let me down. A truly modern take on a the classic fountain design.
The Vanishing Point has a retractable nib, like clicking a Bic. Uniquely, for a fountain pen, when the pen is closed it is closed! The ink and nib are surrounded in a sealed chamber. This has resulted in several hundred thousand miles flown without a single leak.
But how does it write? I like a fine nib and the Pilot comes with a beautifully flexible 18 carat gold one -- it is super fine. The pen is really well balanced and feels solid in my hand. It is heavy but in the best way. Writing is a joy! I find Pilot's cartridge ink to be fast drying and the black is dark enough for me (I'm a long time Quink fan but we can discuss ink all day...)
It is perfect for writing in a Boing Boing moleskine!