PILOT Hi-Tecpoint Liquid Ink Pens are generally suitable for air travel. Keep in mind that airplane pressure changes might cause ink leakage, so secure the cap during the flight. Opt to carry pens in your carry-on to monitor them closely. While most airlines permit a reasonable number of pens, large quantities should adhere to airline policies. To prevent leaks, consider placing pens in a resealable plastic bag. Regulations for pens and liquids vary by airline and destination, so consult the airline's guidelines before flying.