Lightweight regular flashlights under 7 inches should be fine. But if there is any sense that the flashlight has been designed to cause injury the TSA officer might refuse to permit it on board the aircraft. And flashlights really do get confiscated by the TSA.

Should I always carry a flashlight?

A flashlight will light up those dark areas or spaces so you can be safe and give yourself an advantage over any potential threats – whether that is a person looking to do harm or a possible obstacle in your path you could trip over. When the lights go out having a flashlight will be your best option to get to safety.

Why should you own a flashlight?

When walking down a dark street or to your car at night, they can help you spot potential dangers while still far enough away to gain an advantage. For Self-Defense - A flashlight will enable you to temporarily blind a would be attacker and gain valuable time to get away.