<p>Fighters, bombers and attack aircraft represent the main defense/offense 'teams' of the US Air Force, but a multitude of aircraft are in use to maximize their effectiveness. For years the leader in the field, the United States operates a varied and highly capable reconnaissance fleet, but one which again faces a considerable change in the light of reduced force levels and doctrinal changes.
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<p>Two basic reconnaissance missions are outlined in USAF doctrine: strategic and tactical. The first produces intelligence data necessary for formulating national policy, while the latter produces data necessary for commanders in battle. By the nature of intelligence-gathering and the use to which the data is put, aircraft types designed for strategic reconnaissance purposes can provide outstanding tactical intelligence, and vice versa.
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<p>Since the withdrawal from service of the Lockheed SR-71, the US Air Force is without the services of a high-speed, high-altitude, air-breathing reconnaissance platform, although rumors emanating from the California/Nevada desert suggest that secret high-speed aircraft are under development, and may even be in service, to provide capability in this arena in advance of that possible with the SR-71.
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<p>Currently, the 9th Wing has the Lockheed U-2R in service, this aircraft being able to fly for long durations at high altitudes with a multi-sensor suite to provide continuous intelligence. Chief among its sensors is a long-range stand-off radar which can produce high-resolution imagery of enemy forces in both peacetime and war. Also carried are communications intelligence receivers for eavesdropping and emitter locators to precisely monitor the whereabouts of hostile radars. The aircraft retains the ability to carry optical sensors for conventional photography.
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<p>Another important reconnaissance fleet is that of the Boeing RC-135s, which collects signals intelligence of all kinds, specialities being the individual and intimate classification of radars, notably those of air defense networks. Intelligence is normally gathered from friendly or international airspace during long sorties that take the RC-135s to many parts of the globe. Three specialist RC-135s are employed to monitor ICBM tests of other nations and for theatre missile reconnaissance.
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<p>Both RC-135 and U-2R are of great use during time of tension or war, but are normally considered as strategic platforms. In the tactical arena, where the standard method of intelligence gathering is with fast- and low-flying jets flying over individual targets, the US Air Force relies on the McDonnell Douglas RF-4C Phantom, although the age and limitations of the basic airframe mean that it is fast approaching retirement. The RF-4C still uses traditional film and optical sensors for most of its intelligence gathering, but the current trend is towards video and infra-red imagery, as evidenced by the European Tornado reconnaissance variants which have dispensed with film altogether. Accordingly, a new tactical reconnaissance system is under development for the US Air Force, to be carried in podded form by F-16s.
