The airlines ultimately decide what a passenger can bring with them while on the road. They may let you to travel with knives or swords provided they are properly packed in sealed baggage that is checked for cargo loading. However, I would advise against this because most countries require all weapons to be disarmed before flight departure times.
There have been cases where passengers have attempted to take knives on flights and have been prevented from doing so. For example, in 2004, a man was prevented from boarding his United Airlines flight at Chicago's O'Hare International Airport with a folding knife in his pocket. He argued that the knife was used for work and was not intended as a weapon. The judge disagreed and found him guilty of a crime punishable by up to 15 years in prison. He was ordered to surrender the knife to police upon arrival at his destination.
Since then, there have been several other cases involving passengers trying to board flights with knives. All of these cases involve some form of legal interpretation regarding what type of knife can be taken on a plane. Most courts have ruled that even if you're going to use the knife for work, it still falls under the definition of a weapon.
The only way around this would be to ask the airline to allow you to carry a concealed weapon.
In the United States, you can only bring a knife as checked baggage on an aircraft. TSA requires that all blades be transported in checked baggage! Knives are not permitted in carry-on baggage. Sharp objects in checked luggage should be sheathed or tightly wrapped to avoid injuring baggage handlers and inspectors.
The reason given by TSA for this rule is to prevent unnecessary delays at security checkpoints. If a passenger tries to bring a knife into the cabin, the airline staff will need to find an alternative method of securing the knife while checking the passenger's other items. This could cause considerable delay at the checkpoint, so it is best to leave knives in the baggage compartment.
However, there are exceptions to this rule. If you are traveling with a valid license to carry a concealed weapon, then your knife will be allowed in the cabin under these same conditions. Also, if you are traveling with a fully enclosed knife (such as a folding knife), then it can be carried in the cabin.
Checked bags weigh more, so airlines reserve the right to charge additional fees for overweight bags. In addition, some airlines have a limit on the size of a bag they will allow, so check with the airline prior to purchasing your ticket to make sure you don't run into any size restrictions.
Also note that most airlines prohibit liquids, including water, in the cargo hold.
Since 2001, the TSA (Transport Security Agency) has increased security, and any things that can be used as weapons, including knives, are now prohibited from cabin bags. Round-bladed butter knives and plastic knives are the only sorts of cutlery permitted aboard flights. However, these items can be carried in your carry-on bag or checked baggage.
In fact, most knives can be carried on board the plane without any problems at all. However, some countries have strict laws regarding what types of knives you can take on board aircraft, so it's best to check with the airline before traveling to ensure that there are no restrictions. For example, Japan prohibits any blade longer than 3 inches (7.5 cm), while Germany prohibits any knife capable of cutting anything other than meat.
The only real danger with knives is if someone is trying to harm themselves. If you see something suspicious, like someone who may be emotionally disturbed or suffering from illness/injury, then call security immediately. They can deal with situations like this more effectively than you can as a passenger, especially since they are not going to mind if you report them first!
Travelers may put blades, pocketknives, and Swiss army knives in their checked bags if required, but they may not bring them onto the airline in their carry-on luggage, according to Transportation Security Administration (TSA) instructions. Checked baggage blades are taken out of their sheaths and placed in the x-ray machine's tray. The same goes for knives in travelers' pockets. Pocket knives can be kept in the pocket during screening.
TSA regulations prohibit passengers from carrying any weapon or dangerous object on an airplane. This includes items such as hammers, box cutters, and weapons or ammunition designed to cause harm to people or animals. Additionally, some items that look like weapons may be prohibited because experts cannot determine their actual use. These items include toy guns, fake swords, and airsoft guns. If you pack anything that is considered a weapon, it has to be packed in your checked bag and will not make it onto the plane with you.
Checked bags weight more than 7kg (15lb) full capacity. If your bag weighs more than this, you will need to pay extra to check it. Each additional 5kg over the limit costs $150. You can usually find out how much your bag weighs by looking on the receipt that comes with it. If the weight is not listed there, call the airline directly to ask how much it weighs.