The helicopter is probably the most versatile of all the flying machines that man has invented. Since the early days of the invention of the helicopter, it has progressed to the point that it has become an indispensable vehicle in our modern society.
The helicopter has revolutionized aircraft and brought versatility to what aircraft can be used for. The ability of the helicopter to hover, take off, and land in a small space, lift heavy loads, and fly at low altitudes has made it a useful aircraft that has been modified for specific needs.
A helicopter is a common sight in most parts of the world, whether it is to monitor traffic, police a community, or transport cargo. These aircraft have become an important part of our modern society’s infrastructure and provide a valuable service in many different roles.
1. Compound Helicopter
A compound helicopter is a description given to a helicopter that uses a different propulsion method to achieve forward motion.
In traditional helicopters, forward motion is achieved by tilting the main rotor forward, which pushes air back and down, propelling the aircraft in a forward direction.
In a compound helicopter, there is an additional propulsion method that is used to drive the helicopter forward and allow it to obtain much faster forward speeds.
In some configurations of a compound helicopter, the forward motion is provided by a tail-mounted propeller which generates forward thrust. The more common configuration for a modern compound helicopter is to have a turbo jet engine to provide forward momentum.
In cruising flight, the compound helicopter can slow down the main rotor and use the forward thrust supplied by other means. This allows for faster forward flight and makes the helicopter more fuel-efficient, which increases the range of the aircraft.
A distinguishing feature of compound helicopters is the addition of small, stubby fixed wings on the fuselage of the helicopter to provide additional lift from the forward motion of the aircraft.
2. Single Main Rotor Helicopters
Early helicopter designs used multiple main rotors to provide lift and stability to the aircraft. Most modern helicopter designs have done away with multiple main rotors except for specific applications and have opted for a single main rotor accompanied by a vertical tail rotor.
Helicopters with this single main rotor configuration are also known by the term “monocopter” in reference to the single main rotor.
All single main rotor helicopters need an anti-torque, vertically mounted rotor on the tail of the aircraft. The single main rotor generates torque which makes the body of the helicopter want to spin in the opposite direction to the main rotor.
The tail rotor is required to counteract this torque-spin and keep balance the torque forces, keeping the body of the aircraft straight. The drive for the tail rotor is usually supplied from the same engine that powers the main rotor. This takes some power away from the main rotor, reducing the lift power and speed of the helicopter.
Some monocopter models have a separate motor powering the tail rotor, which increases the power the main motor can deliver to the main rotor. This will increase the lift capacity and speed of the helicopter.
The Eurocopter EC225 Super Puma is an example of a single rotor helicopter with a vertical anti-torque tail rotor.
3. Tandem Rotor Helicopters
A Tandem rotor helicopter is a name given to helicopters that employ dual main rotors in a specific configuration. There are other dual-rotor helicopters, but the configurations of the rotors are different.
Tandem rotor helicopters have two main rotors and no anti-torque tail rotor. The arrangement of the rotors in a tandem rotor helicopter is with one rotor mounted at the front of the helicopter and the second rotor mounted at the rear of the helicopter and in a slightly higher position than the front rotor.
The two rotors spin in opposite directions, canceling out each other’s rotational torque, thus obviating the need for a tail rotor. The reason for the height difference between the rotors is so that the rotors will not collide with each other when they are in operation, even if they flex under heavy load.
The rotors are also tilted slightly towards each other, which provides greater vertical control of the aircraft when hovering.
A Boeing CH-47 Chinook carrying a Land Rover.
This dual rotor configuration is most commonly used in large helicopters that are designed to lift heavy loads. Each rotor has its own engine, and with no tail rotor, the full power of each engine goes into the respective main rotor. This power gives these aircraft incredible lifting capability and also superior speed.
Examples of tandem rotor helicopters include the Boeing CH-47 Chinook and the Bristol Belvedere.
4. Tiltrotor Helicopters
Tiltrotor helicopters are in a class of their own since they are a crossover between a helicopter and a fixed-wing aircraft.
These helicopters have dual rotors, one mounted at the end of each wing. The wing is shaped like a normal wing of a fixed-wing aircraft. The rotors and engines are mounted on nacelles at the end of the wings that can rotate from the vertical helicopter-style position to the horizontal fixed-wing-style position.
When the rotors are in the horizontal position, they provide vertical lift in the same way as a normal helicopter rotor. When the rotors are swiveled to the vertical position, they are positioned in the same orientation as propellers for a fixed-wing aircraft. In this position, the rotors provide forward or horizontal thrust, and the lift component is provided from the shape of the aircraft wing.
A Boeing V22 Osprey helicopter.
These aircraft were developed mostly for vertical takeoff and landing or VTOL capability for use aboard aircraft carriers and other ships.
This rotor configuration gives the aircraft the capability of carrying heavier weights during takeoff and higher cruise speeds than traditional helicopters.
An example of a tiltrotor helicopter is the Bell Boeing V-22 Osprey.
5. Coaxial Helicopters
Coaxial helicopters are another example of a dual main rotor helicopter. The configuration of the rotors in these helicopters, however, is that they are on the same axis, one above the other.
The rotors spin in opposite directions, so each rotor counteracts the torque from the other rotor, meaning a tail rotor is not required on these aircraft.
There are a number of other benefits from this rotor design, including a reduction in noise and in an increased payload of the helicopter. These helicopters are also more compact because of the lack of a tail rotor, which allows them to access tighter spaces than traditional helicopters.
This makes these helicopters popular in marine applications where the aircraft needs to land in the small space of a ship’s deck or other marine structures such as oil rigs.
The downside to coaxial helicopters is the rotor drive, and mountings are more complex than in other helicopters, with many more moving parts in the mechanics. This makes them more prone to mechanical problems than other helicopters.
Examples of coaxial helicopters include the Kamov Ka-27, a Russian helicopter, and the Sikorsky S-97 Raider from the USA.
6. Intermeshing Rotor Helicopters
The Kaman HH-43 Huskie is an example of an intermeshing rotor helicopter.
Intermeshing rotor helicopters are another example of dual-rotor helicopters, but the configuration of the rotors is side-by-side on angled pylons. These helicopters are often referred to as synchropters in reference to the synchronized rotation of the rotors.
The mast or pylon that each rotor is mounted on is angled slightly outward to each side of the helicopter, and the rotation of the blades is synchronized with each other so that the rotors do not collide with each other. This is where the name intermeshing is derived from, where the rotation of the rotors mesh together like the gears on a cog.
The two rotors spin in opposite directions, canceling the torque of each rotor, and eliminating the need for a tail rotor on this type of helicopter.
Most intermeshing rotor helicopters have two blades per rotor, but some versions, such as the Kellett XR-10 from the USA, have 3 blades per rotor.
Intermeshing helicopters are known for their stability and the heavy loads they can transport, even though the angled rotors lose some of their lift capability in this configuration.
Another example of an intermeshing rotor helicopter is the Kaman HH-43 Huskie used by the US military but has since been retired.
7. Air Ambulance Helicopter
An air ambulance helicopter preparing to transport a patient in Palm Beach, Australia.
Medical emergencies are one scenario where the helicopter has changed the outcome for critically injured or ill people. The ability of the helicopter to hover, land in small spaces and fly at low altitudes made it the ideal aircraft to be converted to a medical air ambulance.
An ambulance helicopter is usually fitted with medical equipment similar to an advanced life support ground ambulance. The helicopter outfitted in this way needs to have enough internal capacity to accommodate the injured or severely ill passenger as well as trained medical personnel to take care of the patient during the flight.
Helicopters functioning in this role have saved countless lives where timeous medical care is crucial to the survival of the victim or patient.
8. Troop Carrier Helicopter
From its inception, the helicopter has had military application, and the defense forces of many nations saw the benefit that this type of aircraft could offer to various branches of its military force. The troop carrier helicopter became a means to get troops to a battle zone or to launch an attack with speed and agility.
This type of troop delivery is known as an air assault. The troops can be delivered directly to the frontlines without the need to land at an airstrip and then ferry the troops to the battleground with ground-based vehicles.
As a troop carrier, there are various models of helicopters that have been developed for this function, from large capacity troop carriers to small strike force troop carriers.
The helicopter can land or hover just above the ground to deposit the troops on the ground, or the helicopter can hover at a higher altitude, and the specially trained troops can rappel from the helicopter to the ground. This method of troop delivery is particularly useful in areas of dense bush or tall trees.
9. Attack Helicopter
A Boeing AH-64D Apache Longbow attack helicopter in Japan
An attack helicopter is a style of helicopter that has been developed as a strategic strike craft. The ability of the helicopter to hover, fly at low altitude, and make use of ground topography for cover, made it the ideal type of aircraft to develop into a weapon.
Early attack helicopter prototypes were capable of carrying a limited number of troops. Modern attack helicopters generally do not have space to carry passengers or troops but are usually manned by a two-man crew, often sitting one behind the other in tandem.
The pilot of the helicopter sits at the back of the aircraft, while the co-pilot, who is also the gunner, sits in the front seat and controls the targeting systems and the armaments of the helicopter.
Attack helicopters can be used to effectively and accurately support ground troops with supporting ground fire. They are also used to attack strategic enemy ground targets such as base camps, supply convoys, and stockpiled ground supplies.
Attack helicopters proved very effective against tanks and are often deployed as a countermeasure to these types of ground-based weapons.
Attack helicopters have even proved effective against other fixed-wing military aircraft due to their ability to hide in the radar clutter provided by ground terrain such as trees and topography.
10. Gunship Helicopter
A gunship helicopter is a name that is sometimes used interchangeably with an attack helicopter, but there is also a different connotation for a gunship helicopter.
Some small capacity troop deploying helicopters, such as the Huey, were often outfitted with heavy armaments such as machine guns and rocket launchers. This modification allowed these helicopters to drop troops on the frontline and then provide them with aerial support during the firefight.
The machine guns that are mounted on these helicopter gunships are often large-caliber guns such as .50 caliber and that have a high rate of fire. These guns, combined with the rockets, make them effective against not only enemy troops but also enemy vehicles, buildings, and entrenchments where the enemy has dug in.
11. Observation Or Reconnaissance Helicopters
Helicopters have the ability to fly at low altitudes, high altitudes and to operate with stealth. These abilities of the helicopter resulted in many models being developed specifically for observation, reconnaissance, and espionage roles, both for military and civilian use.
Helicopters can be packed pull of electronic surveillance equipment, infra-red and night vision cameras, laser targeting, radar, and communications listening devices.
The stealth ability of helicopters outfitted in this manner allows them to avoid detection by radar and even by physical senses of the enemy.
Helicopters used in this role have been invaluable in the sector of information gathering for scientific, law enforcement, and military purposes.
12. Helitack Helicopter
A helitack helicopter collecting water.
Helitack is the term used for helicopters that have been outfitted to be used in fighting and controlling wildfires. These helicopters are widely used in firefighting roles and have special capabilities which make them crucial equipment for these services.
Helitack helicopters can be rigged with a helibucket, which is a large volume bucket that is suspended beneath the helicopter. The bucket is filled by submerging it in a body of water such as a lake, dam, reservoir, or river.
The filled bucket is flown over the area of the fire, and the contents are dumped from the bucket over the fire to extinguish the fire or control the spread of the fire.
Other helitack helicopters are fitted with tanks that are filled while the helicopter is on the ground via a hose, or a siphon is used to fill the tanks from dams, lakes, and rivers. The helicopter then flies over the fire and opens the tank doors to release the water and douse the fire.
Helitack helicopters are also used to deliver firefighters and supplies to areas that are impassable by road, or the fire has cut off passage of the ground-based vehicles. Firefighters are trained to rappel from these helicopters into the fire zones to fight the fires at ground level.
13. Aerial Crane Helicopters
An Erickson aerial crane helicopter
Aerial crane helicopters are helicopters that have been designed specifically for lifting and carrying awkward or heavy loads. These types of aircraft have both civilian and military applications.
Aerial crane helicopters are very different-looking helicopters and often resemble something out of a science fiction novel rather than what we commonly expect a helicopter to look like.
Where aerial helicopters are used most frequently is in the logging industry, where they are used to extract felled trees from heavily wooded areas where passage by other vehicles is not possible.
They are also used in construction to lift large building components into place on tall buildings and bridges, and similar large-scale structures.
The military used aerial cranes to lift heavy tanks into and out of battle zones or to deploy and retrieve other large items of war machinery that cannot be relocated by any other means.
The Sikorsky aircraft manufacturer is a company that commonly supplies helicopters for this application, and the Sikorsky S-64 Skycrane is a good example of an aerial crane helicopter.
14. News And Media Helicopters
News and media helicopters are usually smaller helicopters that are rigged with specialized equipment, usually in the form of cameras and video cameras.
Helicopters outfitted in this way are usually used to cover news stories such as police car chases, hostage situations, and other news items where law enforcement restricts access to the scene.
These helicopters are also used to provide footage of public events such as sporting events, music festivals, and other newsworthy events such as floods, fires, and other natural disasters.
Historically, these aircraft were also used to report on the morning and evening peak rush hour traffic conditions, but this function has largely been replaced by sensors and traffic cameras which are cheaper to run for this type of news.
15. Scientific Research Helicopters
Helicopters are frequently called upon by the scientific community for the purpose of gathering data on natural events or phenomena that are difficult to get a person to on the ground.
The difficulties could be due to inaccessible locations or conditions that are dangerous for someone to get too close to at ground level.
A helicopter loaded with sensitive scientific gear is the ideal vehicle to monitor and collect data on events and situations of scientific interest without putting people directly in harm’s way to collect the data.
Helicopters have been used in this way to monitor and collect scientific data on volcanic eruptions, tsunamis, and hazardous events such as the Chernobyl nuclear reactor disaster.
16. Tourism Helicopters
Helicopter tours of the Grand Canyon are a popular attraction near Las Vegas, Nevada.
Tourism is an enormous worldwide industry, and many tourism companies seek to offer their guests something different to attract clients in an extremely competitive market.
Helicopters have been introduced to the tourism industry in a number of different ways. Helicopters are used to give tourists a birds-eye view of local attractions, both natural and manmade. Flights over Niagara Falls, Stone Henge, Angel Falls, structures such as bridges and tall skyscrapers are all popular with tourists.
Flights around beautiful mountain ranges and coastal landscapes are also popular helicopter flights in the tourism sector. Helicopters are also often used to get tourists to hard to reach out of the way tourist destinations that are inaccessible by other means.
Helicopters that are favored for this type of application have large windows and seating arrangements that are conducive to giving occupants a great view. A popular helicopter for this type of tourism is the Bell 427.
17. Search And Rescue Helicopters
Helicopters have been used in search and rescue operations for many decades. They are the perfect aircraft for this type of application because they can fly low and at slow speeds, which allows for inspection of the terrain below in greater detail.
Another aspect of helicopters that makes them ideal for search and rescue is that once the person has been found, the helicopter can, in most cases, pick up the person immediately without having to call in another vehicle to the location to affect the rescue.
Helicopters that are ideal for search and rescue efforts are ones that have long-range capability, sufficient capacity to pick up multiple people, fitment of a winch to extract injured people, and also the fitment of sophisticated electronics for rescues such as infra-red and night vision capability.
A popular helicopter for this type of application is the Sikorsky S-92 which has all these capabilities or the capacity to retrofit the equipment. It also has a good range and large capacity inside for rescue personnel and for multiple rescue victims.
18. Maritime Helicopters
Maritime helicopters are aircraft that are deployed for various types of work in coastal regions of the world. The most famous of these is the Coast Guard, who use helicopters for a variety of functions as part of their normal operations.
The Coast guard uses helicopters for search and rescue operations, medevac missions from ships and oil rigs. The helicopters used for these types of missions are similar to the ones used for overland search and rescue missions, requiring long-range capacity and winching capability. The maritime helicopters need to be able to rugged enough to withstand the adverse weather along the coast that they are often called upon to work in.
The Coast Guard also effectively uses helicopters for crime control and prevention, such as combating drug and human trafficking. For this purpose, they need helicopters that are both fast and armed.
19. Police Helicopters
An LAPD police helicopter flying over Los Angeles
Law enforcement makes extensive use of helicopters in the execution of their duties and to thwart the intentions of criminals.
Helicopters are often used in law enforcement to track criminals during car chases, locate suspects on foot using heat-sensing cameras and other such technology, and get the jump on criminal operations.
Helicopters are widely used in specialized branches of law enforcement such as SWAT and the DEA. In these branches, they are used to deploy specially trained officers in various crime-fighting situations. The helicopter allows for swift response of these officers and agents and gives law enforcement the advantage of the element of surprise over criminals and criminal operations.
As criminals and criminal syndicates have become more advanced in their illicit activities, law enforcement has needed to respond in kind by using technology and equipment to combat crime. The helicopter is a key ingredient for many law enforcement agencies that gives them the upper hand in their operations.
20. Commuter Helicopter
Helicopters are often used as people carriers by companies that need to get their staff out to difficult, hard-to-access work sites. Helicopters are the perfect vehicle for this type of work because of their capability for long-range flight and their vertical takeoff and landing ability.
Companies that manage oil rigs use helicopters to ferry staff to and from the oil rigs after their work cycle on the rig is complete. Oil companies also use helicopters to deploy teams to repair oil pipelines in remote regions.
Areas with many islands use island hopper helicopters to transfer workers from island to island. Tourist resorts often use helicopters for this purpose to transfer their staff to and from remote island holiday resorts and well as tourists.
The helicopters used for this type of function are usually aircraft that have good range and good passenger-carrying capacity. Even if the distances are not far, they need to be able to transport 6 to 8 people at a time as well as carry luggage.
21. Nature Conservation Helicopters
Nature conservation efforts make extensive use of the helicopter for the various tasks that are part of these types of efforts.
Nature conservation helicopters are often fitted with radio-tracking equipment to track animals that have tracking collars fitted to monitor their movements and to be able to locate the animals when necessary.
Helicopters are also used in nature conservation to dart wild animals for relocation or for veterinary treatment. The person doing the darting will usually sit in the open door of the helicopter while the pilot gets as close to the animal as possible for an effective shot of the tranquilizing dart.
Helicopters are also used to herd wild animals to group them for capture and relocation. Where game counts need to be done in conservation areas to determine the numbers of a species in the area, a helicopter is a very efficient and quick method to get this tedious but necessary job done.
The helicopters used for conservation tasks are usually small aircraft that have low maintenance costs and are fuel-efficient to fly. They usually have low carrying capacity, often only two people, the pilot and one other person.
22. Agriculture Helicopters
Agriculture is not a sector that many people consider as an industry that makes use of helicopters. However, helicopters are used quite extensively in certain farming sectors.
Cropduster helicopters are often used as an alternative aircraft for crop spraying. Traditionally, this was the domain of fixed-wing aircraft, but helicopters have proven effective in this role due to their ability to fly slow and low.
A helicopter in New Zealand sprays crops on a farm.
This ability results in the chemicals being more accurately sprayed on the crops without the wind blowing the material too far and wide, which reduces waste and improves coverage on the crops.
Helicopters are also used on large cattle farms where cattle need to be herded to move them to new pasture or to round them up to be taken to market. In this instance, the helicopter has taken over the role of the cowboy.
The helicopters used in agricultural roles are usually very small helicopters; often, even one-man helicopters are used. Larger helicopters such as the iconic Huey have been used in the past, but most crop spraying operations have moved over to smaller, more cost-effective helicopters for this role.
A new development in this industry is the use of unmanned drone helicopters to perform crop-dusting tasks for agriculture.
23. Unmanned Aerial Systems Helicopters
Unmanned helicopters fall into the broad-spectrum description of UAVs or unmanned aerial vehicles. Helicopters that fall into this category come in a variety of sizes, depending on their intended application.
These types of helicopters are used by the civilian, military, and law enforcement entities for a range of purposes. For civilian use, they are used increasingly for crop spraying, security surveillance, and checking fence lines of farms and industrial facilities for disruption.
Law enforcement mostly uses them for covert surveillance, while the military use them for surveillance and weapon payload delivery.
24. Mars Helicopter
The Mars Helicopter Ingenuity (Source: NASA)
Helicopters have even made it past the boundaries of earth and our local atmosphere! NASA has developed a MARS helicopter, which they named Ingenuity.
It is a small helicopter that is powered by a solar-charged battery and electric motors. There were many challenges that needed to be overcome for the development of this helicopter, the main obstacle being the thin Martian atmosphere.
The Mars helicopter has made several test flights on the surface of the red planet already, and the initial performance of the aircraft has been impressive and surpassed the expectations of the scientific team.
The success of the Mars helicopter is allowing for advances to be made for similar, larger aircraft to be sent to Mars and other planets in our solar system for detailed exploration missions that will give mankind insight into our galactic neighbors that would otherwise have to wait for manned missions, which are much more complex and expensive to accomplish.
Conclusion
Helicopters have, without a doubt, been a game-changer in the versatility of aircraft and flight in general for mankind.
Helicopters are workhorses of the aviation world that have changed the lives of countries and communities by providing disaster relief to areas that were inaccessible to other forms of transport.
Their versatility has allowed the helicopter to be modified and adapted to many functions that far surpassed the original and mostly military application for this aircraft.
The helicopter has become an indispensable aircraft that many sectors of our society and industry have come to rely on as a staple piece of equipment that no other type of vehicle can match.