Safe air traffic is a must for the industrial, political, social, sanitary and human world. If we could't travel by air, chaos and panic would sweep over the world.

Therefore, the history of air travel is full of arrangements and developements which were made to make travelling by air safer and faster. In the modern age, the high-tech airplanes are getting more and more reliable and safe.

Although, by now we can cope quite well with weather and technical challenges, but we haven't found the perfect way of defending our planes against criminals. They still can get through the check points and can take explosives and weapons on the board of civil aircrafts. This is a threatening danger for the passengers and the air crew.

We all have heard about hijacked planes-sometimes there were disasters, and unfortunately the stories sometimes came to an unhappy end.

The airlines have spent a great sum of money on developing modern and safer checking systems. High-tech devices were involved in these systems, and they were arranged to make it impossible for the terrorists to carry weapons, explosive materials or anything else that can be dangerous for the passengers or the air crew on the board.

While trying to pin out the potential terrorists more effectively, the importance of luggage control became more considerable.

This is called passive protection and nowadays it is the only way we try to protect our planes and people. It means that the potentially dangerous fellows can't be forbidden to board the plane, if they are not seriously suspected, they have a clean record and they have a passport and an air ticket. Since it's impossible to seize the potential criminals, the dangerous objects that can be useful for the terrorists are searched for.

This is a limited way of protection, because a razor or a paper-knife can become a dangerous weapon in the hands of a terrorist who want to assume power on an airplane. It is an unavoidable situation, even if the safest and strictest check takes place at the boarding.

That's only the simplest way of hijacking an aircraft. The professional criminals use much more cunning methods to take some weapon or explosive onto the board with them. We must keep an eye on them when we are reloading, refilling, checking and repairing the planes. The airplanes are often unguarded at the airports, which is really irresponsible from us. Moreover, the vacuum bags must be mentioned, as well, because the explosive materials can't be sifted out in them. These bags can be hidden under the garment or in the luggage. Although checking become more and more effective, this way of passive protection will be always imperfect, and so, a totally safe defence system can't be accomplished by it. The cunnest criminals will always be one step ahead of us, and be able to sneak through the check points and the passive defence system.

We talk about active protection when we try to cope with the terrorists in an emergency situation on the board of a public aircraft. It means that we disarm and disable the terrorists (hijackers) when they are trying to grab the power on the board.

It's important not to endanger the passengers, the pilots and the flight attendants in a situation like that. It can't be accomplished and put in practice easily, and it is an extremely dangerous defence method for the following reasons: 1. When an airplane is flying high, the pressure difference can cause serious damage both for the plane and the passengers if the terrorists fire a weapon or an explosion tear in the hulk of the plane. This can even have the airplane crashed down.

2. It is too complicated to always have a large number of armed guards on the planes, and it is financially a nonsense.

3. If we just arm the members of the flight crew or hire a single armed guard on the board, a group of terrorists can attack some members of the flight crew or the armed guard, and after disarming them, they even can get their weapons. So that's too dangerous, and not worth risking.

The inadequacy of the above mentioned methods can be corrected by my defence system. It is a complex and coherent defence system that assures maximum safety.

The description of my patent is the following: We can't avoid to protect the cockpit sufficiently. If the cockpit is safe, then the terrorists or hijackers can't be a threatening factor for the pilots. This can be solved by armouring the cockpit's front wall including the cabin's main and side-doors, too.

These doors can only be opened by a finger-print identifier and a number lock. There should be hidden crenelles on the armoured wall that can be opened in emergency.

This defence system deals not only with the cockpit, but with the passenger cabins, with the corridors and with the other areas and rooms whose defence is important. At these places, the ceiling should be covered with a very strong material (plastic or kevlar strengthened by carbon-fibre) and this cover can only be removed by a special tool. There would be launchers placed between the ceiling and the strong ceiling cover. These launchers could be fixed in a tilted angle on counting§ that can be immobile or are able to be moved in every direction (across and down). The barrel of the launchers should be hidden, so there would be slots covered by a thin intransparent film on the false ceiling. The launchers would be loaded with sleeping bullets (bullets that cause unconsciousness), so the hijackers would fall in sleep almost immediately after being shot. The launchers would be equipped with a barrel, a magazine and with a device that removes the cartridge and can prevent accidental gunfire.

Besides the armoured cockpit and the sleeping bullet launchers, there is an other important segment in this active defence system: the usage of cameras. These mini cameras would be set on the ceiling at the most important areas, especially on the corridors between the passenger cabins. They should be camouflaged as relieves on the ceiling or as other decorations and stanchions. The mini cameras would move synchronised with the launchers, and they would also be driven by electromotors, so this way it would be possible to check the passenger cabins and the areas and rooms that are important for the safety of the aircraft.

Both the launchers and the mini cameras would be connected with the computer set up in the cockpit or with the console in the cockpit. This can be solved by sensors, remote transmitters or multi-plug electric cables. This way the crew can check what's happening on the board-especially in the areas and rooms that have a great importance in the defence system, and they can get information about the terrorists' position. After getting known where the hijackers are, they become easy target even in an emergency, and sleeping bullets can be launched from the cockpit.

This defence system can be developed, and this way become even more safe, with the following equipments: If there were hidden signal buttons on the board- especially in the passenger cabins and in the rooms and areas that are important in the defence system-whose position would only be known for the flight attendants. The signals (beeps or flashes) could be seen or heard in the pilot cabin. The flight attendants can even carry an emergency signal unit with themselves. It could also make the defence system safer, if there were hand weapons in the cockpit which are built for launching sleeping bullets and are equipped with a suitable magazine. It should be closed in a safe that has got a number lock, and only the security officer and the pilots would be entitled to open it and use the sleeping pistols in emergency.

These hand weapons could even be used from the cockpit, if there were hidden crenelles on the wall and the doors of the pilot cabin. The crenelles could be opened and closed from the cockpit. They can be extremely useful when a terrorist, hijacker or any shifty criminal tries to come close to the door of the cockpit in order to place some explosives there and to blow up the armoured wall and doors. The security officer always takes the sleeping pistol with him when he leaves the cockpit and enters the passenger cabins, and he is allowed to use it in case he considers it necessary.

The sleeping bullet consists of a needle, a canister, the canister's cover, a magazine and a weight. The needle is fixed on the canister which has flexible walls and is full of chemicals that cause unconsciousness. This flexible canister has got a hard cover with a percussion-cap at the end of it. The canister is pressed on the flange of the cover, and is loaded with solid or gas explosives. There are notches in the barrel, as well as on the hard cover of the bullet, to make the hit of the sleeping bullet even more precise. After hitting the terrorist, the weight compresses the flexible canister in the cover, the chemicals come out of it and enter the hijacker's body through the needle, who falls asleep in a few seconds.

There should be a room on the public aircrafts where the criminals can be imprisoned after they have become unconscious and have been handcuffed. This compartment must have strong walls and a safe lock, and it must be large enough for several terrorists. Accidentally, the sleeping bullet can hit a innocent passenger or a flight attendant, as well. In this case they should get an injection of stimulating chemicals, which neutralises the effects of the sleeping bullet. These neutraliser bullets should be closed up in the safe that can be found in the cockpit.

There are three enclosures (No. 1, 2 and 3) attached to the description of this patent. These drawings show the position and movement of the launcher and the launcher itself, the vertical segment of the sleeping bullet, and the hand weapon that can be manually used to launch the sleeping bullet directly.