Are Helicopter Blades Sharp? If you are looking for how to make helicopter rotor blades. Suppose you want helicopter blades for sale instead. Then this article is what you need.
A helicopter main rotor has blades with an inboard airfoil having a high lift-drag ratio for efficient hovering and a “shock-free” outboard airfoil for high speed cruise. Each rotor blade has a structural section composed of metal spars and metal skins forming torque boxes accompanied by a nonstructural fairing and after body. Secured within the torque boxes and the after body are honeycomb cellular structures of a metallic and nonmetallic material, depending on the area wherein the cellular structure is secured. At a point along the blade radius, between 60% and 75%, the upper metal skin of the aft torque box changes from an outer contour surface of the blade to a flat surface parallel to and above the cord line. A fairing of fiberglass skin is secured over a nonmetallic cellular structure over the flat surface of the upper metal skin to complete the upper outer airfoil contour outboard of the 75% radius dimension. The lower outer airfoil contour is the metal skin of the aft torque box followed by a fiberglass skin joined at a trailing edge with the fiberglass upper surface.
how to make helicopter rotor blades
Are Helicopter Blades Sharp
This is a continuation of application Ser. No. 430,344, filed Jan. 3, 1974, now abandoned.
This invention relates to an airfoil, and more particularly to a helicopter rotor blade for optimum hovering, maneuverability and high speed performance simultaneously.
In the early 1950’s efforts were begun to develop an airfoil having a high-lift forward chambered profile. Such a profile was eventually developed and used in production blades. In the mid 60’s, a thin chambered blade section was developed and this blade was also used on production models of main rotor blades and tail rotor blades. In the late 60’s, a blade operating in the transonic speed range was developed utilizing the well-known “peaky” approach. These extensive efforts to develop improved airfoils were prompted in part by activity in helicopter development to increase the forward flight speed. Further, as new uses for helicopters developed increased maneuverability was a prerequisite. This increased maneuverability produced particularly severe stress and force profiles over a rotor blade length.
To meet the demands on the rotor blades for this new generation of high speed helicopters with greater maneuverability, many attempts have been made to provide a rotor blade with the necessary surface area and the required mechanical stress characteristics. Main rotor blades for helicopters have, heretofore, been made with a nose spar or leading edge spar constructed of a U-shaped channel of light weight material but having high impact resistance. Stainless steel sheets in the form of the U-shaped channel provided a suitable material for the leading edge spar. The trailing edge of the nose spar has been supported by a rigid shear strip closure member to provide shear resistance. An upper and lower skin, suitably shaped to the appropriate airfoil design, is attached at the leading edge thereof to the trailing edge of the nose spar. This skin terminates in a sharp trailing edge seam. The interior of the skin covered portion of the blade is filled with a honeycomb fillerlike cellular structure to impart the necessary stiffness thereto.
A feature of the present invention is to provide a rotor blade having a high lift-drag ratio with high drag-rise mach numbers and improved maximum lift characteristics. A further feature of the present invention is to provide a rotor blade that simultaneously provides for efficient hovering, low compressability losses in high speed level flight, and high-G maneuverability.
In accordance with the present invention, there is provided a rotor blade having a thickness greater than that of a structural member over a substantial portion of the blade length. This thickness greater than the structural member extends from near the blade root to a point near the blade tip. The blade comprises a structural member coupled to a mast pylon and extends radially therefrom. Encompassing the structural member and connected thereto is a nonstructural airfoil to establish the desired blade contour while minimizing stiffness of the composite blade.
In accordance with a more specific embodiment of the present invention, a rotor blade is provided that includes a nose spar extending lengthwise of the blade along the leading edge thereof and open to the rear at upper and lower trailing edges. Mating with the upper and lower trailing edges of the nose spar is a spar closure forming a structural torque box. Located on a lengthwise axis of the blade and positioned from the spar closure on the side opposite the nose spar is an aft spar that has the trailing edge of a lower forward body skin secured thereto. A leading edge of this lower forward body skin is secured to the nose spar at the lower trailing edge thereof. Upper and lower after body skins are secured at their leading edges to the nose spar and the aft spar, respectively, and are coupled together along the trailing edge to terminate the blade in a sharp trailing edge seam. Secured to the upper leading edge of the nose spar is an upper forward body skin that is secured at the trailing edge to the aft spar between the upper after body skin and the lower forward body skin to a transition point along the blade length and then forms the forward upper contour of the airfoil. This upper forward body skin forms an aft torque box with the spar closure.
A more complete understanding of the invention and its advantages will be apparent from the specification and claims and from the accompanying drawings illustrative of the invention.
helicopter blades for sale
Top 10 Luxury Helicopters in the World
Most people have heard of personal and charter jets, but luxury helicopters are the genuine gems. Not only are these aircraft comparatively less expensive, but helicopters can approach places that bulky jets can’t. Having a private or commercial helicopter is expedient, more environment friendly, and a symbol of status. Celebrities including Brad Pitt and Angelina Jolie and Donald Trump own a luxury helicopter, and this slot market has grown considerably in recent years due to demand from the rich.
They are well-appointed with all the newest technology, and interior seating marks that are designed in fine Italian leather upholstery.
Therefore the list of top 10 luxury helicopters is given below:
1. Augusta Westland AW119 Ke Koala:
The Koala is chiefly used by law enforcement, but it can easily provide accommodation to a group of corporate directors traveling on business. It has a VIP services quite adequately, with premium leather upholstery and seating for about 6 passengers and 2 operators. The Koala reaches a top speed of 166 mph (267 km/h) and a range of 618 miles (995 km). Price ranges from $1.8 to $3 million.
2. Eurocopter Hermès EC 135:
Though this brand of luxury helicopters is not suitable for long distant trips, is has a class apart built. The typical EC 135 will cost you a mere $4.2 million, but the one with the interior design from the best in class designer will cost you up to $6 million. The top speed is 178 mph, but the range is just 395 miles.
3. Augusta Westland AW109 Grand Versace VIP:
Augusta Westland teamed up with the Italian fashion house Versace to produce a super luxury interior for this fancier version of the AW109. The top speed is about 177 mph and a range of 599 miles. The mere difference is that all 599 of those miles will be more luxurious for the VIP passengers. Hence, will cost you $6.3 million price tag and the helicopter is fully covered in Versace leather, design and exterior.
4. Eurocopter Mercedes-Benz EC 145:
If you’re a Mercedes fan, now you can fly your preferred brand helicopter too. A regular EC 145 costs about $5.5 million, so the Mercedes version is going to cost anywhere around $7 million. But it’s totally worth it. No other Mercedes can go 153 mph while flying 17,000 feet above the ground. It has all the luxury of the famous German sports.
5. Eurocopter EC 175:
The EC 175 made its wonderful first appearance at the Paris Air Show in 2009. The chief feature of the EC 175 is that it can hold 16 passengers contentedly inside. The top speed reaches 178 mph (286 km/h), with a range of 345 miles (555 km). It costs whooping $7.9 million.
6. Eurocopter EC 155:
This is a luxurious chopper. Its top speed is an impressive 200 mph with a range of 533 miles. It can seat as many as 13 passengers; this spacious EC 155 aircraft will cost you $10 million.
7. Sikorsky S-76C:
The Sikorsky S-76C is more generally known as Black Hawk. The massive interior is large sufficient to fit up to a dozen passengers, but the seating occupies 4 passengers in Black Hawk model. It reaches a top speed of 178 mph (286 km/h) and has a range of 473 miles (761 km). It would cost you a $12.95 million.
8. Augusta Westland AW139:
The AW139 is appropriate for law enforcement, armed patrol and firefighters. It has a capacity to seat 8 passengers. The AW139 can reach an unbelievable top speed of 193 mph (310 km/h), with a range of 573 miles (922 km). It carries a beautiful interior costing you a hefty $14.5 million.
9. Bell 525 Relentless:
Like the Gulfstream 650 jet, the Bell 525 Relentless helicopter isn’t on the market currently. This chopper is going to cost $15 million. They predicted that the seating will be for 16, a top speed of 162 mph, and a range of 460 miles. This bright yellow Relentless with amazing seating will cost you a fortune.
10. Sikorsky S-92 VIP Configuration:
The S-92 can safely accommodate 9 passengers in its extensive interior cabin. The prices vary exponentially if you plan on decking the interiors with gold or crystal. The top speed of the S-92 is around 194 mph (312 km/h), with a range of 594 miles (956 km). The prices range from $17 million to $32 million.
Helicopter charter can be the most stress-free travel familiarity you will ever have. Which includes being able to travel outside of airports to reach vital meetings or even other flights in a different airport. Though rich class can afford these luxury helicopters, they are worth the investment.