How long can a helicopter hover Why is it dangerous to hover too long, don t tell me there is no gas

First, let's talk about the power problem when hovering, because more power is needed to support hovering, so the rescue must hover against the wind, by the way, I forgot to say, not all rescues are hovering, most, most of them are actually ships sailing at a small speed, *** walking with the ship at the same speed against the wind, so it looks like hovering from a distance or on the ship, and very rarely the real hovering is because either someone falls into the water, or the ship loses power, so, while more power is needed, It also increases the load on the engine, and when a single engine appears, it is extremely easy to cause ** to the crew, especially the lifeguards who are approaching or have just left the ship on the steel cable. Second, let's talk about the problem of hovering, hovering in the eyes of ordinary people is actually not so simple, hovering is to consume more energy than normal flight, and there must be a good reference, many pilots do not like to do a long time of hovering, because hovering is not a simple two mouths can hover, in the rescue, surrounded by an endless sea, sometimes a ten-level gale, at this time, the pilot is like walking blindfolded, although there is a horizon indication, But for life rescue, to be accurate to the point of hovering, it is very difficult, which requires the perfect cooperation of the captain, the winchman, the co-pilot, if the ship is larger, the captain can refer to the ship mast and so on for approach or hovering, but the contradiction is that the wind and waves are strong, the hull shakes badly, the mast will swing very strongly, then refer to the mast, the natural reaction of people will follow the mast, so that the aircraft will be difficult to stabilize, in order to avoid danger, the height of the captain will also change, if the ship is small, there is no reference, The captain only looks at the sea surface then it is more difficult to reference, but also to reserve a certain amount of energy to deal with a single engine, if the hovering is unstable, it will also have a certain impact on the lifeguards hanging on the steel cable and even danger, you can imagine the difficulty of hovering at sea rescue Third, the danger is: the crew, in case of a single engine, either go-around, or a forced landing on the surface, *** engine is on the entire aircraft, and the forced landing is also more difficult, in case the wind and waves are not right, it is easy to sink, so that the entire crew is likely to sink with the aircraft.

Lifeguards at work, in case of go-around, if the steel cable is not released in time, it is very likely to be dragged out, and the strong pulling force is likely to make the lifeguard hit the boat and be dangerous. Even if all this happens, in the case of strong winds and waves, it is possible that the steel cable will be wound somewhere in the hull, and in the bump up and down the hull, it will drag *** into the sea?

Hovering too long is not too dangerous, at most there is no gas.

The rotor is like a rotating "bamboo dragonfly", which generates lift when it rotates, flies upward, and decreases when the rotation speed decreases. If we constantly give it a force and control it as necessary, the "bamboo dragonfly" will not only not fall, but will keep rising and falling according to the size of the lift. In life, the spokes of the bicycle wheels and the fan blades of the electric fan form a disc once they rotate, which will not penetrate by wind and rain, especially the wind generated by the electric fan not only brings us the coolness of summer, but also makes us obviously feel a thrust.

The rotor is many times longer than the blades of an electric fan. When it rotates at high speed, the thrust generated will be thousands of times that of the fan. This force is huge, so that dozens of tons of *** can hover and rise and fall at will.

This force is enormous, making dozens of tons of ***.

Why don't you walk in the air?

Many friends think that there is not much difference between *** and airplanes, and in some ways it is. For example, they all fly in the atmosphere, and they all use aerodynamic forces to fly freely in the blue sky. But don't forget one thing, the reason why *** is *** must have its reason.

There is a propeller on it, which relies on its rotation to generate lift, and the flight principle and structure are completely different from those of an airplane. Mainly composed of other parts such as rotors, fuselages, engines, etc., propellers can also be divided into three types, which are single-rotor, double-rotor and multi-rotor. Single-rotor type***In order to resist torsion, a tail wing will be installed at the tail to balance the reaction torque.

To hover, the rotors must rotate constantly to provide an upward force to the aircraft. Being able to hover, the credit of the tail rotor is not negligible. Without its force, I am afraid that it will keep spinning like a spinning top and will not be able to maintain the correct bearing, which is a nightmare for the driver.

However, some *** do not have a tail rotor, and other measures may have been taken.

Ordinary aircraft lack the necessary conditions to hover, so flying in the air cannot be carried out casually. Anything that wants to leave the surface and fly into the air has to fight gravity. As we all know, the gravity of the earth is downward, and if an ordinary plane wants to fly into the air, it must have an upward force to overcome it.

The wing must move relative to the air, and without movement, there is no lift. Therefore, the plane can only fly all the time, always generating lift, and once it stops, it will fall from the sky like a stone and tear it apart.

It's too amateurish to ask, and it's hard.

First, there are many kinds, big ones, small ones, military, civilian, which one do you say?

Second, how long can it be suspended, it depends on the maximum fuel load of the aircraft, and the fuel consumption when it can hover, which also needs to consider the state of hovering, whether there is ground effect, altitude;

To put it simply, it is possible for the same aircraft to hover from hours to more than ten hours.

In the cockpit, there is a throttle variable distance control lever, referred to as the throttle variable distance lever, which is inseparable from it to control the lifting and retreat of the aircraft. If the pilot gradually lifts the throttle pitch lever upwards to make the total lift exceed the weight of the fuselage, it will leave the ground and rise vertically, which is the same as the principle of bamboo dragonfly ascent; If the pilot pulls the throttle pitch lever down slightly, when the total lift of *** is equal to its weight, *** will hover in the air and do not move; If you want the aircraft to descend, just continue to lower the throttle pitch lever so that the total lift of *** is less than its weight.

It is mainly composed of the fuselage and lift (including rotor and tail rotor), power, transmission and airborne flight equipment. The rotor is generally driven by a turboshaft engine or piston engine through a mechanical transmission system composed of a propeller shaft and a reducer, and can also be driven by the reaction force generated by the jet at the tip of the propeller. At present, the practical application is mechanically driven single-rotor and dual-rotor, of which the single rotor is the most numerous.

The maximum speed can reach more than 300km h, the dive limit speed is nearly 400km h, the ceiling can reach 6000m (the world record is 12450m), and the general range can reach about 600 800km. The transfer range of the internal and external auxiliary fuel tanks of the aircraft can reach more than 2000km. There are different take-off weights according to different needs.

The largest heavy *** currently in service in the world is the Russian Mi-26 (with a maximum take-off weight of up to 56t and a payload of 20t).

The outstanding feature is that it can do low-altitude (several meters above the ground), low-speed (starting from hovering) and the nose direction of the same maneuvering flight, especially can take off and land vertically in a small area. Because of these characteristics, it has a wide range of uses and development prospects. In the military aspect, it has been widely used in ground attack, airborne landing, transportation, logistics support, battlefield ambulance, reconnaissance and patrol, command and control, communication and liaison, anti-submarine mine clearance, electronic countermeasures, etc.

In civil use, it is used in short-distance transportation, medical rescue, disaster relief and life-saving, emergency rescue, hoisting equipment, geological exploration, forest protection and fire fighting, aerial photography, etc. The transportation of personnel and materials between offshore oil wells and bases is an important aspect of civilian use.

At present, compared with aircraft, the vibration and noise levels are higher, the maintenance and overhaul workload is larger, the use cost is higher, the speed is lower, and the flight range is shorter. The way forward is to improve on these aspects.

Because it has a unique internal structure. The distinctive wings are the blades of the blade known as the rotor or propeller. With this special wing, it can ascend, descend and hover in the air.

The propeller blows the wind downwards to form a thrust to the ground and control *** in the air.

Can stop in the air, why is that? It is also inseparable from enough lift to support the weight, and only then can it fly in the air. However, the lift is generated by the rotors that are constantly spinning above its head.

When *** stays in mid-air, its rotors are still spinning, and the lift generated by the rotors is exactly equal to the gravity that *** is subjected to, but the direction is opposite to gravity. Therefore, *** can neither advance nor retreat, neither raise nor lower, and stop in mid-air peacefully. In addition, what makes people interested is that the spinning trade can also be tilted forward, backward, left and right.

If it leans forward, it creates a forward thrust, so *** flies forward.

In the same way, the rotor is tilted backwards, left, and right, and it flies backwards, left, and right accordingly, and the operation is also very flexible. The tail is also very distinctive, its tail is not only upturned, but also installed on a "fan". This "fan" can function as a propeller, and its axis is parallel to the ground, commonly known as a "tail rotor".

It acts like a rudder and makes a turn to the left or right.

The above ** are from the Internet).

Flight.

The principle is to rely on the rotation of the rotor to obtain the lifting force of the source air. Other aircraft fly on the principle of relying on fixed-wing gliding to obtain the lift force of the air. Therefore, *** can hover in the air, but other aircraft cannot.

Of course, there is also an aircraft that can hover in the air, and such an aircraft is also a special fixed-wing aircraft, which uses a tail nozzle to eject air flow into the air and suspend in the air. Such an aircraft not only has the speed and flexibility of a fixed-wing aircraft, but also has the best vertical take-off and landing function. It is a special form of fixed-wing aircraft that can take off and land vertically.

When hovering in the air, its gravity is counteracted by the vertical lift created by the rotation of the propeller. Other aircraft cannot achieve stable vertical lift due to different constructions and cannot hover.

This problem actually involves the flight mechanism of rotary-wing aircraft and fixed-wing aircraft, and the following Eagle Aviation Edition explains the flight principle of these two types of aircraft respectively.

the principle of flight of fixed-wing aircraft;

There are currently three main types of power systems for fixed-wing aircraft: turboprops, turbojets, and turbofans. We won't say much about the nature of engine work here, and one of the common points of the three power forms is that the thrust that pushes the aircraft forward will be produced in the working state, and this thrust is mainly to resist the resistance of the aircraft.

By the lift of the propeller. When other aircraft are flying, the rapid flow of air around the wings produces lift, and if it is stationary, the air around the wings does not flow and does not produce lift, so other aircraft cannot.

Due to the gravitational force, all objects on the earth fall naturally without the help of external forces, and the centrifugal force generated by the propeller is perpendicular to the body, so this force can cancel out gravity. The reasoning produced by other planes is parallel to the body, and this does not cancel out the force generated by gravity, so there is no way to hover!

Because there is a propeller on the head, when the propeller rotates, it will produce lift, which just counteracts the gravity of the propeller, so it can hover in the air

Because there is a propeller, it can only be rotated in the air by the rotation of the propeller, while other aircraft do not have propellers, so they cannot be rotated and stopped in the air.

Helicopters have a central propeller.

Because the wings of *** are on it, the rotation produces air currents, which can float, and other aircraft rush forward by power.

Why can a helicopter stay in the air?

The car drives on the ground, stops when you want, and walks when you want, very freely; But when an airplane flies in the sky, it can't be so free. This cannot be done for a normal aircraft. However, there is one type of aircraft that has the ability to hover in mid-air, and it is a straight plane.

Why can a helicopter stay in the air?

Anything that wants to leave the ground and rise into the air has to fight against the biggest enemy of all, gravity. Gravity is the attraction of the Earth to the surrounding objects, and the "weight" we usually feel is the manifestation of this attraction. The direction of the Earth's gravity is downward, and it strives to bind all objects on the Earth firmly to the ground.

For an airplane to rise into the sky, it needs to have an upward force to overcome the effect of gravity, which depends on the lift generated by the wings. However, there is a condition for the wing to generate lift, that is, it must move relative to the air; There is lift when there is movement, and there is no lift without movement. Therefore, the plane can only generate lift when it flies on one side; If, once stopped, the wings and the air have no relative motion, the lift will disappear.

Without lift support, the plane will fall from the sky like a stone.

Helicopters likewise need to have enough lift to resist their own weight in order to fly in the air. The lift of a helicopter is generated by the rotors that rotate above its head. When the helicopter stops in mid-air, its rotors are still rotating, and the lift generated by the rotors is exactly the same as the gravitational force of the helicopter but in the opposite direction.

As a result, the helicopter can neither advance nor retreat, neither raise nor lower, and stand firmly in mid-air to carry out its mission.

In recent years, a high-speed jet with vertical take-off and landing capabilities has emerged. When flying and landing, this type of aircraft can turn the tail nozzle of the jet engine into a downward jet, and use the reaction force of the jet to hold the aircraft up. In this way, it can also hover in the air if necessary.