THE VOLOCOPTER 2X IN DETAIL
My last bird in Iraq was Any information on her wereabouts would be appreciated. I might have a source for some parts. I was wondering if you would know how I could find out what happened to my UH-1H I am trying to find flight logs that would show what my husband was doing on his huey missions between 30 July and 23 Dec Is there somewhere logs or records are kept?
All the best to you. We are having a rededication ceremony for her this weekend, on 12 May. Mainly a period in the late 60s where the records I have found were incomplete. Sorry for the late notice, I was just putting some info together for the ceremony and found this site. I was suggested this website through my cousin. I am now not positive whether or not this post is written by way of him as nobody else know such specific about my trouble.
I am regaining some fond memories of slicks hueys. I served in the st airborne and to this day appreciate all that slicks did for us troops. WOW enjoyed the pictures. Trying to find a model of this helicopter for my husband. He never would talk about his experiences in Viet Nam until lately. We have joined a VA group and this has been good for him. If anyone knows where a model can be bought please send me info.
Your email address will not be published. Posted by huey25 on January 19, in Collection. Prealsun December 19, 7: Chuck daniels June 7, Jim Lee June 25, 3: Wong October 12, 7: McCaw March 18, 1: David Gatson April 17, 4: Jim Dickens April 25, Jamie Thompson May 23, 3: Marc Knoles October 30, 8: Ray Owens May 26, 9: I did several tours as a crew chief on the Huey.
Robert Smith June 26, 7: Dan August 7, 8: Jim Rankin August 18, Gary A Boyer September 4, 3: John Sterling October 12, John W Fulcher Jr January 23, 9: Lisica December 25, 5: The design that Igor Sikorsky settled on for his VS was a smaller tail rotor. The tail rotor pushes or pulls against the tail to counter the torque effect, and this has become the most common configuration for helicopter design, usually at the end of a tail boom.
The use of two or more horizontal rotors turning in opposite directions is another configuration used to counteract the effects of torque on the aircraft without relying on an anti-torque tail rotor. This allows the power normally required to drive the tail rotor to be applied to the main rotors, increasing the aircraft's lifting capacity.
There are several common configurations that use the counter-rotating effect to benefit the rotorcraft:. Tip jet designs let the rotor push itself through the air and avoid generating torque. The number, size and type of engine s used on a helicopter determines the size, function and capability of that helicopter design.
The earliest helicopter engines were simple mechanical devices, such as rubber bands or spindles, which relegated the size of helicopters to toys and small models. For a half century before the first airplane flight, steam engines were used to forward the development of the understanding of helicopter aerodynamics, but the limited power did not allow for manned flight. The introduction of the internal combustion engine at the end of the 19th century became the watershed for helicopter development as engines began to be developed and produced that were powerful enough to allow for helicopters able to lift humans.
Early helicopter designs utilized custom-built engines or rotary engines designed for airplanes, but these were soon replaced by more powerful automobile engines and radial engines.
The single, most-limiting factor of helicopter development during the first half of the 20th century was that the amount of power produced by an engine was not able to overcome the engine's weight in vertical flight. This was overcome in early successful helicopters by using the smallest engines available. When the compact, flat engine was developed, the helicopter industry found a lighter-weight powerplant easily adapted to small helicopters, although radial engines continued to be used for larger helicopters.
Turbine engines revolutionized the aviation industry, and the turboshaft engine finally gave helicopters an engine with a large amount of power and a low weight penalty. Turboshafts are also more reliable than piston engines, especially when producing the sustained high levels of power required by a helicopter. The turboshaft engine was able to be scaled to the size of the helicopter being designed, so that all but the lightest of helicopter models are powered by turbine engines today.
Special jet engines developed to drive the rotor from the rotor tips are referred to as tip jets. Tip jets powered by a remote compressor are referred to as cold tip jets, while those powered by combustion exhaust are referred to as hot tip jets.
An example of a cold jet helicopter is the Sud-Ouest Djinn , and an example of the hot tip jet helicopter is the YH Hornet. Some radio-controlled helicopters and smaller, helicopter-type unmanned aerial vehicles , use electric motors. Radio-controlled helicopters may also have piston engines that use fuels other than gasoline, such as nitromethane. Some turbine engines commonly used in helicopters can also use biodiesel instead of jet fuel.
There are also human-powered helicopters. A helicopter has four flight control inputs. These are the cyclic, the collective, the anti-torque pedals, and the throttle. The cyclic control is usually located between the pilot's legs and is commonly called the cyclic stick or just cyclic.
On most helicopters, the cyclic is similar to a joystick. However, the Robinson R22 and Robinson R44 have a unique teetering bar cyclic control system and a few helicopters have a cyclic control that descends into the cockpit from overhead.
The control is called the cyclic because it changes the pitch of the rotor blades cyclically. The result is to tilt the rotor disk in a particular direction, resulting in the helicopter moving in that direction.
If the pilot pushes the cyclic forward, the rotor disk tilts forward, and the rotor produces a thrust in the forward direction. If the pilot pushes the cyclic to the side, the rotor disk tilts to that side and produces thrust in that direction, causing the helicopter to hover sideways. The collective pitch control or collective is located on the left side of the pilot's seat with a settable friction control to prevent inadvertent movement. The collective changes the pitch angle of all the main rotor blades collectively i.
Therefore, if a collective input is made, all the blades change equally, and the result is the helicopter increasing or decreasing in altitude.
The anti-torque pedals are located in the same position as the rudder pedals in a fixed-wing aircraft, and serve a similar purpose, namely to control the direction in which the nose of the aircraft is pointed. Application of the pedal in a given direction changes the pitch of the tail rotor blades, increasing or reducing the thrust produced by the tail rotor and causing the nose to yaw in the direction of the applied pedal. The pedals mechanically change the pitch of the tail rotor altering the amount of thrust produced.
Helicopter rotors are designed to operate in a narrow range of RPM. The purpose of the throttle is to maintain enough engine power to keep the rotor RPM within allowable limits so that the rotor produces enough lift for flight. In single-engine helicopters, the throttle control is a motorcycle-style twist grip mounted on the collective control, while dual-engine helicopters have a power lever for each engine. A swashplate controls the collective and cyclic pitch of the main blades.
The swashplate moves up and down, along the main shaft, to change the pitch of both blades. This causes the helicopter to push air downward or upward, depending on the angle of attack.
The swashplate can also change its angle to move the blades angle forwards or backwards, or left and right, to make the helicopter move in those directions. There are three basic flight conditions for a helicopter: Hovering is the most challenging part of flying a helicopter. This is because a helicopter generates its own gusty air while in a hover, which acts against the fuselage and flight control surfaces.
The end result is constant control inputs and corrections by the pilot to keep the helicopter where it is required to be. The cyclic is used to eliminate drift in the horizontal plane, that is to control forward and back, right and left. The collective is used to maintain altitude. The pedals are used to control nose direction or heading. It is the interaction of these controls that makes hovering so difficult, since an adjustment in any one control requires an adjustment of the other two, creating a cycle of constant correction.
As a helicopter moves from hover to forward flight it enters a state called translational lift which provides extra lift without increasing power. This state, most typically, occurs when the airspeed reaches approximately 16—24 knots, and may be necessary for a helicopter to obtain flight.
In forward flight a helicopter's flight controls behave more like those of a fixed-wing aircraft. Displacing the cyclic forward will cause the nose to pitch down, with a resultant increase in airspeed and loss of altitude. Aft cyclic will cause the nose to pitch up, slowing the helicopter and causing it to climb.
Increasing collective power while maintaining a constant airspeed will induce a climb while decreasing collective will cause a descent. Coordinating these two inputs, down collective plus aft cyclic or up collective plus forward cyclic, will result in airspeed changes while maintaining a constant altitude. The pedals serve the same function in both a helicopter and a fixed-wing aircraft, to maintain balanced flight.
This is done by applying a pedal input in whichever direction is necessary to center the ball in the turn and bank indicator. The main limitation of the helicopter is its low speed. When the helicopter is hovering, the outer tips of the rotor travel at a speed determined by the length of the blade and the rotational speed.
In a moving helicopter, however, the speed of the blades relative to the air depends on the speed of the helicopter as well as on their rotational speed. The airspeed of the advancing rotor blade is much higher than that of the helicopter itself. It is possible for this blade to exceed the speed of sound , and thus produce vastly increased drag and vibration. At the same time, the advancing blade creates more lift traveling forward, the retreating blade produces less lift.
If the aircraft were to accelerate to the air speed that the blade tips are spinning, the retreating blade passes through air moving at the same speed of the blade and produces no lift at all, resulting in very high torque stresses on the central shaft that can tip down the retreating-blade side of the vehicle, and cause a loss of control. Dual counter-rotating blades prevent this situation due to having two advancing and two retreating blades with balanced forces.
Conversely, the retreating blade flaps down, develops a higher angle of attack, and generates more lift. At high speeds, the force on the rotors is such that they "flap" excessively, and the retreating blade can reach too high an angle and stall. For this reason, the maximum safe forward airspeed of a helicopter is given a design rating called V NE , velocity, never exceed.
During the closing years of the 20th century designers began working on helicopter noise reduction. Urban communities have often expressed great dislike of noisy aviation or noisy aircraft, and police and passenger helicopters can be unpopular making it some annoying because of the sound.
The redesigns followed the closure of some city heliports and government action to constrain flight paths in national parks and other places of natural beauty. Helicopters also vibrate; an unadjusted helicopter can easily vibrate so much that it will shake itself apart. To reduce vibration, all helicopters have rotor adjustments for height and weight. Blade height is adjusted by changing the pitch of the blade. Most also have vibration dampers for height and pitch. Some also use mechanical feedback systems to sense and counter vibration.
Usually the feedback system uses a mass as a "stable reference" and a linkage from the mass operates a flap to adjust the rotor's angle of attack to counter the vibration. Adjustment is difficult in part because measurement of the vibration is hard, usually requiring sophisticated accelerometers mounted throughout the airframe and gearboxes. The most common blade vibration adjustment measurement system is to use a stroboscopic flash lamp, and observe painted markings or coloured reflectors on the underside of the rotor blades.
The traditional low-tech system is to mount coloured chalk on the rotor tips, and see how they mark a linen sheet. Gearbox vibration most often requires a gearbox overhaul or replacement. Gearbox or drive train vibrations can be extremely harmful to a pilot. The most severe being pain, numbness, loss of tactile discrimination and dexterity. For a standard helicopter with a single main rotor, the tips of the main rotor blades produce a vortex ring in the air, which is a spiraling and circularly rotating airflow.
As the craft moves forward, these vortices trail off behind the craft. When hovering with a forward diagonal crosswind, or moving in a forward diagonal direction, the spinning vortices trailing off the main rotor blades will align with the rotation of the tail rotor and cause an instability in flight control.
When the trailing vortices colliding with the tail rotor are rotating in the same direction, this causes a loss of thrust from the tail rotor. When the trailing vortices rotate in the opposite direction of the tail rotor, thrust is increased. Use of the foot pedals is required to adjust the tail rotor's angle of attack, to compensate for these instabilities.
These issues are due to the exposed tail rotor cutting through open air around rear of the vehicle. This issue disappears when the tail is instead ducted, using an internal impeller enclosed in the tail and a jet of high pressure air sideways out of the tail, as the main rotor vortices can not impact the operation of an internal impeller.
For a standard helicopter with a single main rotor, maintaining steady flight with a crosswind presents an additional flight control problem, where strong crosswinds from certain angles will increase or decrease lift from the main rotors. This effect is also triggered in a no-wind condition when moving the craft diagonally in various directions, depending on the direction of main rotor rotation.
This can lead to a loss of control and a crash or hard landing when operating at low altitudes, due to the sudden unexpected loss of lift, and insufficient time and distance available to recover. Conventional rotary-wing aircraft use a set of complex mechanical gearboxes to convert the high rotation speed of gas turbines into the low speed required to drive main and tail rotors. Unlike powerplants, mechanical gearboxes cannot be duplicated for redundancy and have always been a major weak point in helicopter reliability.
In-flight catastrophic gear failures often result in gearbox jamming and subsequent fatalities, whereas loss of lubrication can trigger onboard fire. Recent EASA studies point to engines and transmissions as prime cause of crashes just after pilot errors. By contrast, electromagnetic transmissions do not use any parts in contact; hence lubrication can be drastically simplified, or eliminated.
Their inherent redundancy offers good resilience to single point of failure. The absence of gears enables high power transient without impact on service life. The concept of electric propulsion applied to helicopter and electromagnetic drive was brought to reality by Pascal Chretien who designed, built and flew world's first man-carrying, free-flying electric helicopter. The aircraft first flew on 12 August All development was conducted in Venelles, France. As with any moving vehicle, unsafe operation could result in loss of control, structural damage, or loss of life.
The following is a list of some of the potential hazards for helicopters:. From Wikipedia, the free encyclopedia. Type of rotor craft in which lift and thrust are supplied by rotors. For other uses, see Helicopter disambiguation.
Bamboo-copter and Science and inventions of Leonardo da Vinci. Gas turbine and turboshaft. In recent years it has been producing not just a wide range of scaled models with glow plug powerplants, but increasingly a range of electric models, and has developed a range of sophisticated control technologies which have now moved into the autonomous realm.
The company's compact IMU attitude sensor is one such technology that has been developed to enable autonomous flight, and offers the company a serious competitive advantage in that area. The IMU collects a wide range of information such as attitude angle, acceleration, angular rate and magnetic direction, and enables the helicopter to be remarkably stable in blustery winds — it is a key enabling technology of autonomous flight for helicopters.
Hirobo's first autonomous helicopter will be the HX-1, and the first guise in which we will see it is as a medical emergency and rescue vehicle. The fully autonomous helicopter can be configured for many purposes including aerial photography, search and rescue, surveying and the transport of medical supplies, organs or blood, in order to save lives. The HX-1 has an auto-return function for emergencies and employs coaxial counter-rotating blades and a brushless electric motor as its power source.
Hirobo expects the affordability of the HX-1 to make it possible for smaller organizations that can't afford a manned helicopter to purchase their own transport helicopter. Even more surprising than the sophistication of the HX-1 demonstrated in the videos being shown was the appearance in the HX-1 brochure of the BIT — an all-composite, all-electric, single-person micro helicopter. Last year the BIT was shown for the first time at the Japan Aerospace show, but was not expected to be ready for market until It seems that time scale has been shortened considerably — we were told the BIT would be ready for market in , and a lack of regulations by the United States Federal Aviation Authority would be the inhibiting factor as to the BIT's availability at market.
The BIT manned micro helicopter is expected to be ready for market in