Helicopters are incredible flying machines that test the limits of design and mechanics by their very existence. But which helicopters truly test the limits of aviation? What about helicopters that fly upside down? A helicopter that lifts far more than its own weight? Or a rotary machine that rivaled jet airliners in size? These record setting rotorcraft will give your head a spin!
10. Messerschmitt-Bölkow-Blohm Bo 105: The Aerobat
The iconic steed of Red Bull pilots Chuck Aaron and successor Aaron Fitzgerald, the Messerschmitt-Bölkow-Blohm Bo 105 was a revolutionary contribution to rotary aviation from Germany that stands out as the world’s first aerobatic helicopter. The machine was also new as the first light helicopter to fly with twin engines. That’s right, this super powerful helicopter can do barrel rolls, loops, and fly inverted like the most extreme stunt planes thanks to its incredible design.
Thanks to the capabilities of the Bo 105 as the first ever helicopter to achieve these things, the flight envelope and perceived utility of the helicopter as a machine was revolutionized. The hingeless rotor built from solid titanium is just one great distinguisher of this engineering marvel. The machine can climb at 1,575 feet per minute, and cruise at 150 miles per hour under the power of two 420 standard horsepower Rolls Royce engines. The machines were produced primarily in Germany and Canada, with uses ranging from military to police service as well as in the famed upside down and barrel rolling airshow demos. The helicopter also has been set up for use on aircraft carriers and even fitted out to carry missiles.
9. Mil V-12: The Biggest One
Just how big can a helicopter get? Larger than you imagined, rivaling jet airliners while barely remaining identifiable to the casual eye as a horrifically overgrown helicopter. First flying in 1968, just before the entire project was canceled, the pre-Cold War Soviet Union’s Mil V-12 project was constructed as a transporter with a range of 621 miles and a carrying capacity of one 196 passengers, or a huge load of military cargo. Weighing just over seventy six US tons and designed to fly at 150 miles per hour, the largest helicopter in world history remains unsurpassed.
The rotors each spanned just 220 feet across. Resembling a giant tube with long airplane-like wings each tipped with monster sized rotor blades, the beastly twin rotor whirlybird dwarfed many planes. In 1971, the Soviet Union demonstrated the monster at the Paris Airshow, astonishing witnesses who saw a helicopter with its rotors and vertical capabilities crossed with the look of an airliner. One of the reasons for exceptional Soviet helicopter development works was the need to move giant missiles to far off missile launch sites away from the eyes of Western spy planes more efficiently. Trains were slow and could not reach many areas but huge helicopters could.
8. Westland Lynx: Fastest Helicopter
The speediest conventional helicopter in the world looks humble, yet it retains its hold on the official world speed record for a helicopter flight since 1986. The Westland Lynx reached an average speed of just over 248 miles per hour over Somerset, England under the supervision of the Fédération Aéronautique Internationale (FAI) who bestowed the speed records on the helicopter for fastest speed reached in a helicopter of the 3,000–4,500 kilogram (6,613.868-99,208 pound) weight class plus the Absolute World Record for Rotorcraft. The achievements may have been decades ago but they have yet to be surpassed, as faster rotorcraft since have not been classified as true helicopters, but instead are hybrid aircraft with forward propulsion such as convertiplanes.
The record setting Westland Lynx used specialized main blades designed to fight blade stalling behavior of the blades that would be made worse by high speed flight, a design venture brought to action by the British Experimental Rotor Programme. This programme was a joint effort involving Westland cooperating with the UK Ministry of Defense. High speed main blades, water and methanol power boosts to the engine plus reduction in exhaust pipe size were just some of the overhauls that would propel the helicopter to record speed. Furthermore, the tail rotor and fins were revised to better distribute stresses of high speed flight.
7. Kellet-Hughes XH-17: The Weirdest
If a real life transforming machine got stuck between crane and helicopter mode, the Kellet-Hughes XH-17 would be it. This strange work of aeronautical engineering resembled a helicopter that collided with a crane and flew off as one big mess. The huge contraption was equipped with jet engines mounted to the tips of each rotor in a bid to get the huge machine to fly properly. The machine had its origins in a plan to study and test the concepts of rotary winged craft powered by jets on the rotor tips instead of traditional helicopter drive systems. As work progressed, the need for a humongous machine that could lift and transport large cargo items into challenging areas led to a 1949 contract requesting that the testing rig be made into a functional flying crane.
The resulting XH-17 had a rotor diameter of 130 feet, with a maximum payload of just over 10,000 pounds. Two General Electric J35 gas turbines powered the ungainly machine, while parts from a laundry list of assorted planes including a Waco CG-15 glider cockpit, B-25 wheels, and a B-29 fuel tank were used. Yes, flames and deafening noise were included in the kafuffle that marked each undertaking to get this beast airborne. Eventually the project was abandoned on grounds of practicality.
6. Kaman K-Max K-1200: Strangest Super Achiever
Likely the strangest way to construct a twin rotor helicopter, the multimillion dollar Kaman K-Max K-1200 is a US-built flying machine with synchropter, or intermeshing rotor design. The intermeshing rotors always seem ready to cut into each other, sharing airspace nanoseconds apart, but never touch. Resembling a dolphin in appearance from the side, the rotors angle and intermesh like two gears that never touch, allowing lifting capacity that far outweighs that expected from a helicopter of its size. The laterally compressed body is narrow, making the helicopter look like a fish from a front view perspective.
With its squished design, there is just room for the pilot. The remarkable achievement of this helicopter that has double the rotor and less body than a normal helicopter is the ability to actually lift a cargo load heavier than the empty weight of the helicopter itself! Weighing just 5,145 pounds, the helicopter can take on an additional 6,855 pounds of weight for a maximum gross weight of 12,000 pounds. Uses of the K-1200 include firefighting, search and rescue and supply delivery. Work on a remotely piloted version also led to the creation of a machine that could enter hazardous situations without putting aviators in danger.
5. Bell AH-1 Cobra: First Dedicated Attack Heli
Making its debut in the air in 1965, the Bell AH-1 Cobra was the first fully purpose built attack helicopter, placing impressive close combat air power in the hands of the US Army. Fast, muscular and bristling with firepower, the machine still serves the US Marine Corps over half a century later. The helicopter looks fairly conventional but a closer look reveals many details borrowed from fighter jets, right down to the seating layout. The crew of two sat in series in the long but narrow cockpit with a bubble canopy, the co-pilot/gunner in the front and the pilot occupying the elevated rear seat. The helicopter is sleek, attractive and carries heavy firepower in an extremely efficient layout.
Two short wings protrude from the sides of the fuselage, carrying missiles and minigun pods or cannons under the wings. A total of 3,0000 pounds of weaponry could be carried under the tiny but tough wings. Miniguns, grenade launchers or both were also mounted at the front turret under the nose. Compared to heavy transport helicopters that were the norm prior to the Cobra, the helicopter was a revolutionary step towards maneuverability and capability. Minimalistic skid undercarriage added little weight, leaving more payload capacity for the weapons.
4. Masumi Yanagisawa Engineering System Type GEN H-4: Smallest Helicopter
Looking like a patio chair with a ceiling fan attached, the Masumi Yanagisawa Engineering System Type GEN H-4 Helicopter is to a normal helicopter what a bicycle is to a pickup truck. The Japanese product is a unique flying machine for those brave enough to try it. Created in the 1990s by Gennai Yanigasawa, an electronics company head, the world’s smallest helicopter weighs only 165 pounds, making it the lightest of all helicopters, while its rotor span of 12.8 feet is the least of all.
The machine may be tiny, but it is high tech. The problem of torque and counter-rotation is solved by the machine being coaxial. Instead of a tail rotor, which is not practical to install due to the lack of any tail boom, the machine has two counter-rotating rotors similar to a beginner’s remote controlled helicopter. The machine is not exactly slow, either. Speeds of 56 miles per hour can be reached and the helicopter can stay airborne for 30 minutes at a time. You might really be able to go somewhere perched on this machine. With the rotor blades spinning, the tripod landing gear, seat and rotor hub creates the look of a tiny UFO with a human rider.
3. Dragonfly DF1: Hydrogen Peroxide-Powered
Seating just one person and looking like a shopping cart and a chair with rotor blades attached, the Dragonfly DF1 is not a normal helicopter. It is powered by rockets, fueled by hydrogen peroxide, attached to the rotor tips. Both rockets blast out with power that equates to just over 100 horsepower per rocket motor. The hydrogen peroxide propulsion systems used to make the main rotors spin are only eight inches in length and weigh one and a half pounds each. Because there is no central motor, torque does not form, eliminating the need for powerful tail rotor action.
Instead, a basic, low power tail rotor is just used for light steering duties. The power to weight ratio of the Dragonfly DF1 is impressive, given the 204 horsepower total power contrasted with a machine weight of merely 230 pounds. Ricardo Cavalcanti, Chairman Avimech Int’l Aircraft, Inc. is the creator of the machine, a renowned aeronautical engineer and nature enthusiast from Brazil who sees the creation as a more ecofriendly mode of flight. Ricardo’s machine uses a collective pitch control to gain altitude once the hydrogen peroxide rockets have got the blades spinning at 750 revolutions per minute.
2. De Lackner HZ-1 Aerocycle: The Worst Helicopter
Probably the one of the most unsettling idea ever for a helicopter, the De Lackner HZ-1 Aerocycle was a terrifying contraption that saw pilots standing right above rotor blades. Variations of the machine were tested from 1954 to 1956, showing promise only at first.
A twist grip throttle controller managed power, while the machine was supposed to have steer, pitch and yaw control by leaning. This was meant to be so easy that a soldier could fly the machine in a manner similar to riding a bicycle following less than half an hour’s training. Safety of the machine itself became a glaring issue following crashes. Additionally, upright standing pilots on an Aerocycle would be seemingly easy targets for enemy firepower. The US Army thought there would be an airborne cavalry unit using the machines, but instead the Aerocycle project got scrapped in the end.
Test pilot Captain Selmer Sundby, who spent time in charge of the Aerocycle tests and program development before identifying the machine as being too flawed, ultimately received a Distinguished Flying Cross in 1958 to recognize his service with the project. A single remaining Aerocycle can be seen on display at the US Army Transportation Museum in Fort Eustis, Virginia.
1. VS-300: The First Helicopter
The world’s first legitimately flyable helicopter was the Sikorsky VS-300, the work of rotary winged flight pioneer Igor Sikorsky. On September 14, 1939, the machine first got airborne in Stratford, Connecticut after construction by the United Aircraft Corporation’s Vought-Sikorsky Division. Sikorsky patented the basic design in 1931, with the flights to follow laying the groundwork for the familiar main and tail rotor helicopter ubiquitous in modern times. The machine’s first ventures into the air made use of tethers and it was not until 1940 that unrestricted flight took place. Sikorsky had started his engineering journey by making a windup toy helicopter at age 12.
A current day helicopter pilot would be most concerned by the open cockpit of this machine. The front pod looked something like the cockpit of a World War I biplane fighter, while the main blades swirled above the strapped in pilot. Sikorsky’s pioneering work used drive from a single engine to power both the main blades and anti-torque tail rotor. Not content to be the first normal single rotor helicopter, the VS-300 also got fitted with floats and became the first operational amphibian helicopter, landing and taking off from water with ease. The VS-300 is now an exhibit at the Dearborn, Michigan Henry Ford Museum.