**정찰기**는 적의 활동을 관찰하기 위해 사용되는 군용 비행기이다. 주로 무장을 하지 않는다.
This article concentrates on military aircraft used in this role, though a major civilian aviation activity is reconnaissance and ground surveillance for mapping, traffic monitoring, science, and geological survey. In addition, civilian aircraft are used in many countries for border surveillance, fishery patrols or the prevention of smuggling and illegal migration.

Such efforts long predate the invention of heavier-than-air flight, with experiments using balloons to provide targeting information for artillery beginning in France in 1794, though continued attempts throughout the 19th Century proved militarily useless.
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## 역사
1912년 10월 16일 불가리아의 Albatros 비행기는 전장에서 유럽 최초의 정찰비행을 수행했다.
One of the first aircraft used for surveillance was the Rumpler Taube during World War I, when aviators like Fred Zinn evolved entirely new methods of reconnaissance and photography. The translucent wings of the plane made it very difficult for ground based observers to detect a Taube at an altitude above 400m. The French also called this plane "the Invisible Aircraft", and it is sometimes also referred to as the "world's very first stealth plane". German Taube airplanes were able to detect the advancing Russian army during the Battle of Tannenberg (1914).

Before World War II the conventional wisdom was to use converted bomber types for airborne photo reconnaissance, since these were the only aircraft with the long range needed for the reconnaissance missions. These bombers retained their defensive armament, which was vital since they were unable to avoid interception.

In 1939 Flying Officer Maurice Longbottom was among the first to suggest that airborne reconnaissance may be a task better suited to fast, small aircraft which would use their speed and high service ceiling to avoid detection and interception. Although this seems obvious now, with modern reconnaissance tasks performed by fast, high flying aircraft, at the time it was radical thinking.

As a result, fighters such as the British Spitfire and Mosquito were adapted for photo-reconnaissance during World War II. Such craft were stripped of weaponry, painted in sky camoflague colours to make them difficult to spot in the air, and often had engines modified for higher performance at very high altitudes . Early in the war the British developed a warming system to allow photographs to be taken at very high altitudes. The collection and interpretation of such photographs became a considerable enterprise. [http://www.nzfpm.co.nz/theatres/tow_prec.htm One site] claims that the British, at their peak, flew over 100 reconnaissance flights a day, yielding 50,000 images per day to interpret. Similar efforts were taken by other countries.

Immediately after World War II, long range aerial reconnaissance was once again taken up by adapted bombers, albeit with jet engines, enabling them to fly faster and higher than before. Examples of such aircraft include the English Electric Canberra, and its American development, the Martin B-57.

In the 1950s, the first purpose-built jet covert surveillance aircraft, the Lockheed U-2 was constructed secretly for the United States. Designed for flights over Soviet territory, the plane remained an obscurity until one piloted by Gary Powers was shot down over the Soviet Union in 1960, leading to the U-2 Crisis. Modified versions of the U-2 remain in service in 2002, though its capabilities and operations remain secret. In the 1960s the SR-71 Blackbird, the fastest manned jet-propelled aircraft ever built, was constructed. However, as both the United States and Soviet Union possessed surveillance satellites, interest in new types of photo-reconnaissance aircraft declined.

Another category of surveillance aircraft that has been in vogue since World War II is the maritime patrol aircraft. These are typically large, slow machines capable of flying continuously for many hours, with a wide range of sensors and electronic equipments on board. Such aircraft include the Avro Shackleton, the Hawker-Siddeley Nimrod, the Breguet Atlantique, the Tupolev Tu-95, and from Lockheed, the Neptune and later the Orion. The latter type became famous when a Chinese interceptor collided with the wing of a US Navy example patrolling international waters. The crew of the larger US aircraft made an emergency landing but the fighter crashed killing its pilot. The Orion was impounded by the Chinese authorities and closely inspected before it was dismantled and returned to the USA. The crew were questioned but released prior to the aircraft's return.
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## 현재 사용
이스라엘, 미국, 남아프리카공화국 등 많은나라에서 다수의 UAV(Unmanned aerial vehicle)정찰기가 최근에 실전배치되었거나 개발중에 있다.

현재 개발중에 있는 것은 많지만, 그중에서도 U-2기를 닮은, 고고도 제트추진 비행기인 RQ-4 글로벌 호크와 좀 작은, 중고도의 RQ-1 프레데터가 있다. 슈바이처 항공은 경량 헬기의 원격조종버전으로 개발중이다.

전 세계의 대부분의 공군은 전용 정찰기가 부족하다. 그래서 전투기나 수송기에 정찰카메라를 부착해서 사용한다.

## 정찰기의 형태

### 기존 항공기의 개조
가장 흔한 형태이다. 기존의 전투기를 개량하거나 별도의 고해상도 카메라를 장착한 정찰용 포드를 기존 전투기의 동체 하부에 장착하여 확보 가능하다. 제2차 세계 대전 이전에는 특별한 장비없이 소형 항공기나 복좌형 전투기의 후방석에 카메라를 가진 사진사가 탑승하여 목표물 내지는 목표 해역(지역)을 촬영하곤 했다. 이러한 형태의 정찰기는 고가의 개조 비용을 들이지 않고 값싸게 갖출 수 있고 또 기존에 보유 중인 전투기와 보급 및 부품, 창정비를 공유함으로써 운용 유지 비용도 절약할 수 있다는 장점이 있어 여전히 중요한 비중을 차지한다. 대표적인 기종은 다음과 같다.

RB-47H

RF-4C

Mig-25R

제네럴 더이내믹스 RF16

### 무인 항공기
무인 항공기는 이스라엘군이 베카 계곡 전투에서 사용한 이래 기체가 작아 적의 대공방어망 회피에 유리하고, 대형 전투기가 접근할 수 없는 곳도 접근할 수 있다는 등의 장점으로 인해 선진국에서 채용이 늘고 있다. 자세한 것은 무인 항공기 문서를 참조하라.

### 전문 정찰기
처음부터 전투용이 아닌 정찰 전용기로 개발된 형태이다. 미국의 SR-71과 U-2 등이 있다.

### 전자전 첩보기
앞서 언급된 정찰기들이 모두 고해상도 카메라를 이용하여 항공 사진을 촬영하는 것에 반해 전자전 첩보기는 적군의 통신 및 레이다 주파수에 대한 정보를 수집하는 임무를 수행한다. 적군의 전자 정보(ELINT)를 수집함으로써 효과적인 대응책을 수립하기 위한 기본 자료를 정보부서에 제공하며, 적의 통신망을 감청하는 임무도 수행한다. 이러한 항공기들은 대부분은 편제 상으로는 정규군에 편제되어도 실제 작전 운용은 해당국의 정보부서에서 관할하는 경우가 많다.

대표적인 기종으로 미국의 RC-135(동해에서 북한 공군에 의해 격추된 적이 있다), EP-3(지난 2001년 중국 공군의 F-8II 전투기와 충돌한 기체이다) 등이 있다. 이들의 공통점은 중형 수송기를 개조한 것들이라는 점이다. 장시간 항공 체류를 하여 적의 정보를 수집할 필요성이 있기 때문에 적당한 항속거리와 체공능력을 가졌으면서도 지나치게 큰 크기의 항공기를 회피한 결과이다. RC-135의 원형인 C-135도 수송기이며, EP-3에 사용된 기체는 P-3 오라이언 대잠전기를 전자전 용도로 개조한 것이다.



Another type of surveillance aircraft is the electronic surveillance aircraft. Whilst other military aircraft, including photo-reconnaissance aircraft, have been used for that purpose, several countries adapt aircraft for electronic intelligence (ELINT) gathering. The Beech RC-12 Super King Air and Boeing RC-135 Rivet Joint are examples of this military activity, which helps to reduce opportunities for surprise attack or the risks of training exercises being misunderstood by potential enemies.

As well as the development of UAVs, another recent trend in surveillance aircraft design has been the realization that, with the addition of lightweight sensors and communications gear, every fighter plane and ground attack plane can simultaneously be used to perform surveillance. Hence, the in-development F-35 multirole fighter plane will have extensive surveillance and communications capabilities built in .
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