How to Solve Toque Issue in a Helicopter

choi

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(1) Igor Sikorsky (1889-1972; born in Kiev, Russian Empire (present day Ukraine)) immigrated to US in 1919, founded  Sikorsky Aircraft Corporation in 1923 and sold it to United Technologies Corp in 1929.

Sikorsky
http://en.wikipedia.org/wiki/Sikorsky
("Sikorsky is an English-language respelling of the Slavic surname Sikorski. Derived from the Polish word sikora – meaning 'chickadee/tit' – it was originally the name of a noble Polish-Lithuanian Commonwealth family")

(2) Those who follows me know I introduced an article which stated that earliest helicopter could not fathom why the invention could hover up or down in motionless air but would invariably crashed once it attempted to move OR when wind blows during the upward or downward movement.

(a) Coaxial RC helicopters. R/C Airplane World, undated
http://www.rc-airplane-world.com/coaxial-rc-helicopters.html
(section heading: How coaxial RC helicopters work)

RC in this case stands for Remote Controlled.

(b) helicopter rotor
http://en.wikipedia.org/wiki/Helicopter_rotor
(Most helicopters have a single, main rotor but require a separate rotor to overcome torque. This is accomplished through a variable pitch, antitorque rotor or tail rotor. This is the design that Igor Sikorsky settled on for his VS-300 helicopter and it has become the recognized convention for helicopter design, although designs do vary. When viewed from above, the main rotors of helicopter designs from Germany, United Kingdom and the United States rotate counter-clockwise, all others rotate clockwise. This can make it difficult when discussing aerodynamic effects on the main rotor between different designs, since the effects may manifest on opposite sides of each aircraft.)

(c) helicopter
http://en.wikipedia.org/wiki/Helicopter
(section 3.1.1 Antitorque_configurations)

(i) intermeshing rotors
http://en.wikipedia.org/wiki/Intermeshing_rotors

It pointed to an example: Kaman HH-43 Huskie (First Flight 1947; US Air Force).
* File:HH-43.jpg
http://commons.wikimedia.org/wiki/File:HH-43.jpg
(close-up, oblique view of the helicopter, demonstrating the intermeshing motors)
* File:Kaman HH-43B HuskieCAM07.jpg
http://commons.wikimedia.org/wiki/File:Kaman_HH-43B_HuskieCAM07.jpg
(lateral view of the helicopter)

(3) Invented by Mr Sikorsky, a tail rotor is ONE way to counter the torque of the main rotor in a helicopter. as the Engineering Manager of the Vought-Sikorsky Division of United Aircraft Corporation

(a) Vought-Sikorsky VS-300
http://en.wikipedia.org/wiki/Vought-Sikorsky_VS-300
(Sikorsky as the Engineering Manager of the Vought-Sikorsky Division of United Aircraft Corporation)

Quote: "The first 'free' flight of the VS-300 was on 13 May 1940. While not the first successful helicopter to fly, it was the first successful helicopter in the United States and the first successful helicopter to use a single vertical tail rotor configuration for antitorque.

(b) Vought
http://en.wikipedia.org/wiki/Vought
(The first incarnation of Vought was established by Chance M. Vought and Birdseye Lewis in 1917. In 1928, it was acquired by United Aircraft and Transport Corporation, which a few years later became United Aircraft Corporation)

(4) tail rotor
http://en.wikipedia.org/wiki/Tail_rotor
(section 3 Alternative technologies)

Note:
(a) For Pitch" in the introduction (of this Wiki page), see blade pitch
http://en.wikipedia.org/wiki/Blade_pitch
(section 1.1 Helicopter)
(b) Emergency Anti-torque System for Rotary Wing Aircraft (Manned and Unmanned). Small Business Innovation Research (SBIR), undated.
http://www.sbir.gov/sbirsearch/detail/150944
(c) emergency anti-torque thruster system (EATTS)

There are patents freely available online, which, especially for lack of visual aide, does not seem helpful to me.

The patent owners has established a web site, which is tremendously wonderful for laypersons like me.
http://911antitorque.com

Click the swirl to "launch" the web site.
(i) In the home page, wtch ONLY the video in the upper left corner with the heading "EATTS 3D Video," which actually incorporates many if not all of the other video clips.

I do not have 3D eyeglasses so the words are hard to read. HOWEVER, pay attention to in  demonstration video clips within this video, each showing in animation jet streams released from the mid-section of the helicopter tailboom.

The jet is the product of a
thruster
http://en.wikipedia.org/wiki/Thruster
(A thruster is a small propulsive device)

For tailboom, see the second graphic in
Helicopters. US Centennial of Flight, 2003. Commissionhttp://www.centennialofflight.gov/essay/Dictionary/helicopter/DI27.htm

(ii) In the FAQ section, read the following questions at least, whose answer will show up when CLICKING each individual question.
* 1.What is the EMERGENCY ANTI - TORQUE THRUSTER SYSTEM?
* 2.When was EATTS first conceived?
(A: "his idea, which utilized jets or rockets for anti-torque power")

Sikorsky HOS-1 (R-6) "Hoverfly II." US Coast Guard Aviation History, undated.
http://www.uscg.mil/history/webaircraft/Sikorsky_HOS1.pdf

* 5.What kind of fuel does the system utilize?
* 7.Does the pilot control the thrusters or is it automatic?
* 8.How is this system different from NOTAR?
* 13.What about the location of the thrusters?

(5) coaxial rotors
http://en.wikipedia.org/wiki/Coaxial_rotors
(section 1.4 Disadvantages; section 4 List of co-axial rotor helicopters)


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choi

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Will blades of coaxial rotor in a helicopter collide 双旋翼打在一起?

(1) This was solved with hardware and, in recent decades, software.

(2) "Collision of coaxial helicopter rotors is no more probable than collision of single rotor blades with tail boom. Safe distance between rotors is determined on basis of special methods, calculations, researches and flight tests. At rotor starting and stopping in stormy conditions, rotor collision is prevented by centrifugal flap stops at lower rotor and droop stops at upper rotor. Safety of coaxial rotor scheme is proved by abundant operation experience of Kamov helicopters. KAMOV Company has been designing and manufacturing coaxial helicopter for more than 50 years and has practically polished to perfection the rotor system design."
Kamov Company. Globalsecurity.org, undated.
http://www.globalsecurity.org/military/world/russia/kamov.htm

(3) About the cause of a Kamov helicopter crash.
(a) Kamov Ka-50
http://en.wikipedia.org/wiki/Kamov_Ka-50
(Ka-50 Bort 22 with a distinctive "Black Shark" livery was lost in a crash during 1998. Its pilot Maj.Gen. Boris Vorobyov was killed in the crash)

(b) Good and Bad News for Russian Helicopter Manufacturer, in Monitor. Jamestown Foundation, volume 4, issue, June 24, 1998.
http://www.jamestown.org/single/?no_cache=1&tx_ttnews%5Btt_news%5D=17366&tx_ttnews%5BbackPid%5D=212
("The Ka-32 success was, however, more than offset by the crash last week of a Ka-50 "Black Shark" assault helicopter. That craft was one of only ten in service with the Russian army. It was being flown by the commander of the army's aviation training center, Major General Boris Vorobyov, who was killed in the crash. Reports indicated that one of the helicopter's rotors disintegrated during a high-speed low level flight. (Russian media, June 18, 19)")

(c) The Tragic Crash of a Russian KA-50 "Black Shark" Battle Helicopter. RussianFootageArchive.com, undated (video).
http://www.russianfootagearchive.com/video.php?id=12

【 在 choi 的大作中提到: 】
: (1) Igor Sikorsky (1889-1972; born in Kiev, Russian Empire (present day Ukraine)) immigrated to US in 1919, founded  Sikorsky Aircraft Corporation in 1923 and sold it to United Technologies Corp in 1929.
:  
: Sikorsky
: (以下引言省略...)

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choi

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AAS is acronym of Armed Aerial Scout.
http://en.wikipedia.org/wiki/Armed_Aerial_Scout
, whose page lists the three contenders: Sikorsky S-97 Raider,  AAS-72X and OH-58D/AVX (S-97 and AVX are co-axial).


【 在 choi 的大作中提到: 】
: Will blades of coaxial rotor in a helicopter collide 双旋翼打在一起?
: (1) This was solved with hardware and, in recent decades, software.
: (2) "Collision of coaxial helicopter rotors is no more probable than collision of single rotor blades with tail boom. Safe distance between rotors is
: (以下引言省略...)

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choi

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Jeff Scott, Propeller Torque Effect. Aerospaceweb.org, Feb 25, 2011
http://www.aerospaceweb.org/question/dynamics/q0015a.shtml
(“Do aircraft with piston engines or turboprops experience torque effects like helicopters do?  - question from Tieo Jing Jin “)

Note:
(a) aileron
http://en.wikipedia.org/wiki/Aileron

aileron (n; French, from diminutive of aile wing, aisle--more at AISLE; First Known Use: 1909)
(b) torque
http://en.wikipedia.org/wiki/Torque
(also known as moment or moment of force; section 1 Terminology: This article follows US physics terminology by using the word torque. In the UK and in US mechanical engineering, this is called moment; The magnitude of torque depends on three quantities: the force applied, the length of the lever arm, and the angle between the force vector and the lever arm)

(c) The etymology of yaw (n; vi) is uncertain, whose first known use is 1586.

The etymology of both words (aileron and yaw) are from www.m-w.com.
(d) contra-rotating propellers
http://en.wikipedia.org/wiki/Contra-rotating_propellers
(section 2.1 United Kingdom: Supermarine Spitfire and Seafire)
(e) Macchi M72
http://en.wikipedia.org/wiki/Macchi_M.C.72
(the last photo)

【 在 choi 的大作中提到: 】
: AAS is acronym of Armed Aerial Scout.
: http://en.wikipedia.org/wiki/Armed_Aerial_Scout
: , whose page lists the three contenders: Sikorsky S-97 Raider,  AAS-72X and OH-58D/AVX (S-97 and AVX are co-axial).
: 【 在 choi 的大作中提到: 】
: : Will blades of coaxial rotor in a helicopter col
: (以下引言省略...)

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choi

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A Lottery To Die For. Strategy Page, Oct 15, 2011.
http://strategypage.com/htmw/htatrit/articles/20111015.aspx

Quote:

"In most cases, helicopters are brought down machine-guns, especially heavy (12.7mm or larger) ones. The enemy has also been using portable surface-to-air missiles since 2003, including more modern models, like the SA-16 (which is similar to the American Stinger.) American helicopters are equipped with missile detection and defense (flare dispensers) equipment. Thus the most dangerous anti-aircraft weapon remains the machine-gun.

"Today's helicopters are much more rugged and reliable than those in Vietnam (1966-71, the first major combat use of helicopters).  * * * Today's helicopters are sturdier, partly because of Vietnam experience, and are more likely to stay in the air when hit, and land, rather than crash.


【 在 choi 的大作中提到: 】
: Jeff Scott, Propeller Torque Effect. Aerospaceweb.org, Feb 25, 2011
: http://www.aerospaceweb.org/question/dynamics/q0015a.shtml
: (“Do aircraft with piston engines or turboprops experience torque effects like helicopters do?  - question from Tieo Jing Jin “)
: (以下引言省略...)

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