 |
Business | Industries | Finance | Tax |
| Index: > A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
|
|||||
| First Prev [ 1 2 ] Next Last |
The Sidewinder has a high-explosive fragmentation warhead and an infrared (IR) heat-seeking guidance system. Its main components are an infrared homing guidance section, an active optical target detector, the warhead section, and a rocket motor. The guidance section enables the missile to home in on the engine heat of the target aircraft. An infrared unit costs less than other types of guidance systems and can be used day or night in all weather conditions. The infrared seeker also permits the pilot to launch the missile then leave the area or take evasive action while the missile guides itself to the target.
Developed by the US Navy starting in the late 1940s, the Sidewinder introduced several new technologies that made it simpler and much more reliable than its Air Force counterpart, the AIM-4 Falcon. After terrible experiences with the Falcon in the Vietnam War, the Air Force replaced its Falcons with Sidewinders.
The primary advantage to the Sidewinder was its use of a simple yet very sophisticated detection/guidance system. In WWII the Germans had experiments with infrared guidance systems in a large missile known as the Enzian but were unable to get it to work reliably. The system used an IR detector mounted in a small steerable telescope, and used a vane in front of the mirror to tell on which side of center the target was in order to guide. By continually trying to turn the missile body toward the current direction of the telescope, the missile would guide toward the target using what is known as a pure pursuit.
The Sidewinder improved on this in a number of ways. The first was to replace the "steering" mirror with a system using a mirror that was rotating around a shaft pointed out the front of the missile, with the detector mounted in a fixed location in front of it (not to the mirror). Instead of attempting to track the target in the mirror, the IR sensor would see the target as brief flashes as the mirror lined up with the target. By knowing where the flash was as the mirror spun, the direction (radially) to the target was also known. In addition this system could track the angle-off to the target in a clever manner. If the target was further to the side of the field of view, the flash seen in the detector would be shorter due to the mirror's higher rate of motion at the outside.
Finally this sort of signal made the tracking system both simpler and much better. Instead of simply pointing the missile at the target (which is inefficient) the guidance system, the Sidewinder "remembered" each flash's direction and time. By attempting to zero out the changes, instead of the difference between the detector and missile angles, the Sidewinder flew a course known as proportional pursuit, which is much more efficient and makes the missile "lead" the target.
However this system also requires the missile to have a fixed angle of flight. If the missile spins at all, the timing based on the speed of rotation of the mirror is no longer accurate. Correcting for this spin would normally require some sort of sensor to tell which way is "down" and then adding control inputs to correct it. Instead the Sidewinder engineers came up with a very clever solution. Small control surfaces were placed at the rear of the missile with spinning disks on their outer surface. Airflow over the disk would spin them to a high speed, and if the missile started to roll, the gyroscopic force of the disk would drive the control surface into the airflow and produce the opposite control input. Thus the Sidewinder team replaced a potentially complex control system with a small bit of metal.
A prototype of the Sidewinder, the AIM-9A, was first fired successfully in September 1953. The initial production version, designated AIM-9B, entered operational use in 1956, and has been improved upon steadily since. The first operational deployment of the Sidewinder was during the 1950's with the air force of the Republic of ChinaThe Republic of China ( Traditional Chinese: , Simplified Chinese: ; Wade-Giles: Chung-hua Min-kuo, Tongyong Pinyin: JhongHua MinGuo, Hanyu Pinyin: Zhonghua Minguo) is a de facto sovereign state that currently administers the island groups of Taiwan, Peng on Taiwan. During that period of time, the ROC was engaged in air battles with the People's Republic of ChinaThe People's Republic of China PRC comprises most of the cultural, historic, and geographic area known as China. Since its founding in 1949, it has been led by the Communist Party of China (CPC). It is the world's most populous country, with a population over the Taiwan StraitThe Taiwan Strait or Taiwan Straits is a 180km-wide Strait between mainland China and the island of Taiwan. The strait is part of the South China Sea and connects to East China Sea to the northeast. The narrowest part is 131km wide. Fujian province on the. The United States provided a few dozen Sidewinders to ROC forces which were used to great effect against PRC MiG's, adding a new element to an air war which had formerly been fought only with guns. After playing an important role in ending the Taiwan Strait conflict, US forces made it a central part of their air arsenal.
The Taiwan Strait battles inadvertently produced a new derivative of Sidewinder: shortly after that conflict the Soviet UnionThe Union of Soviet Socialist Republics (USSR ( Russian: ; tr. Soyuz Sovetskikh Sotsialisticheskikh Respublik (SSSR) also called the Soviet Union ( ; tr. Sovetsky Soyuz , was a state in much of the northern region of Eurasia that existed from 1922 until 1 began the manufacture of the K-13/R-3S missile ( NATO reporting nameNATO reporting names were code names for Soviet and Chinese equipment. These were created to facilitate communications between military units speaking different languages. Also, in most cases the actual Soviet names for these items were not known or did n AA-2 'Atoll'), a reverse-engineered copy of the Sidewinder. It was reportedly made possible after a Taiwanese AIM-9B hit a Chinese MiG-17 without exploding, and served as a "university course" in missile design for Soviet engineers. The K-13 and its derivatives remained in production for nearly 30 years.
The Sidewinder subsequently evolved through a series of upgraded versions with newer, more sensitive seekers with various types of cooling and various propulsion, fuse, and warhead improvements.
The AIM-9L ("Lima") model, introduced in 19761976 is a leap year starting on Thursday (link will take you to calendar). Events January January 12 UN Security Council votes 11-1 to admit the Palestinian Liberation Organization January 15 Would-be Gerald Ford presidential assassin Sara Jane Moore is s, was the first Sidewinder with the ability to attack from all angles, including head-on. The subsequent AIM-9M ("Mike") has the all-aspect capability of the L model while providing all-around higher performance. The M model has improved defense against infrared countermeasures, enhanced background discrimination capability, and a reduced-smoke rocket motor. These modifications increase its ability to locate and lock on a target and decrease the missile's chances for detection. Deliveries began in 1983. The AIM-9M-7 was a specific modification to AIM-9M in response to threats expected in the Persian Gulf war zone.
Now entering service is the AIM-9X, a new variant with an imaging infrared focal plane array seeker with claimed 90° off-boresight capability, compatibility with helmet-mounted sights (the new U.S. JHMCS, Joint Helmet-Mounted Cueing System), and a totally new thrust-vectoring system replacing the traditional control surfaces. It retains the same motor and warhead of the "Mike," but its lower drag gives it improved range and speed.
The Sidewinder is the most widely used air-to-air missile in the West, with more than 110,000 missiles produced for 27 nations excluding the United States. The AIM-9 is one of the oldest, least expensive and most successful missiles in the entire U.S. weapons inventory.
It has been said that the design goals for the original Sidewinder were to produce a reliable and effective missile with the "electronic complexity of a table model radio and the mechanical complexity of a washing machine" - goals which were well accomplished in the early missiles.
| Politics | Business | Finance |
 |
 |
 |
|