Because of the pressure difference. The small amount of air trapped in the pen will expand when the pressure in the aircraft reduces. Commercial aircraft pressures are set to about the same as those at 10,000 feet. There will be a higher pressure inside the pen than in the fuselage, the pressures will try to equalise out and may force some of the ink out of the pen in the process.
--NOTE--
The pen should not overflow when you - board - the airplane. It should only happen some time after take off. The pressure when you board the plane is no different from the pressure in the departure lounge.
There was a change in pressure within the cabin. The pen's ink compartment was at higher pressure pressure when you boarded, but the cabin pressure must have decreased enough at altitude to cause the pen to leak.
there is less pressure above the ground so the ink inside it burlge outside and flow in airplane......
Fountain pen liquid is as of course the liquid from a fountain pen.
A fountain pen is used for writing.
a fountain pen is una pluma. thankyou x
There is no Greek god of the fountain pen.
No, a baby fountain pen is not an inkling. An inkling refers to a small or slight idea or understanding, whereas a baby fountain pen is a smaller-sized fountain pen designed for easier handling by children or those with smaller hands.
The word is fountain. water fountain fountain pen soda fountain
Fountain pens.
No it will clog up your fountain pen.
fountain pen
It is called a "fountain pen" because the nib receives a continuous flow of ink from the reservoir or cartridge - which is the "fountain."