Top 10: The greatest Spy planes

Reconnaissance aircraft snoop around potentially hostile nations (or their ships) gathering photographic and electronic intelligence.

Their crews would rather they are not referred to as ‘spy planes’ as this status can affect their safety and treatment if shot down and captured, but this rather more exciting title has stuck.

These shadowy machines shun publicity, quietly changing the course of history and often flying in extremely dangerous or contentious situations. We look at ten crewed aircraft we think are the most important in history.

10: Mikoyan-Gurevich MiG-25R ‘Foxbat’

From the outset, it was planned that there would be a reconnaissance version of the extremely fast and high-flying Soviet MiG-25 ‘Foxbat’. The MiG-25R carried cameras and electronic sensors in Soviet service, as well as in a handful of export versions. The Foxbat earns the clean-up spot on the list because of its impact as an intelligence collector on the international stage.

The March 1971 deployment of Soviet MiG-25s and pilots to Egypt and their unopposed overflights of Israel were a shock to the West. Although their contributions to Egyptian security and intelligence were minimal, their impact on Israeli security was profound.

Even with only two Mach 2.5 overflights a month, the inability of Israeli F-4s and Mirage IIIs to intercept and destroy the Foxbats raised serious questions in Tel Aviv and in Washington about the ability of Western aircraft to engage what was considered the most dangerous Soviet aircraft yet.

The MiG-25R photo intelligence (PHOTINT) overflights were significant escalations in the so-called War of Attrition, which led to the 1973 October War and the brief superpower diplomatic confrontation over possible unilateral Soviet intervention on behalf of the encircled Egyptian Third Army. For the first time, thanks to the Foxbat, Western military leaders had to take Soviet aerial reconnaissance seriously.

9: Business jets

For decades, few nations could afford the sufficiently large and equally expensive aircraft needed to conduct routine communications and electronic intelligence (COMINT and ELINT) collection. That changed with the availability of smaller sensors and on-board analysers as well as the reduced need for multiple operators.

Earlier bulkier equipment required the use of a large four-engined aircraft, hence the existence of RC-135s, EP-3s, and C-130-IIs in American service, Nimrod R.1s in RAF colours, and the occasional French DC-8 and Soviet/Russian Coot. With technology miniaturisation, at last, almost all nations can afford a ‘poor man’s Rivet Joint.’ in the form of a converted business jet.

This resulted in the procurement and conversion of SIGINT variants of large twin-engine business jets or regional airliners such as the Gulfstream IV (used by Sweden), the G550 Nahshons (used by Israel), and Bombardier Global Express Sentinel R1s (used by the UK). Even the United States, with its huge defence budget, is exploring the use of business jets to replace its ageing fleet of RC-135 Rivet Joints.

Given their main purpose, business jets tend to be relatively fast and long-ranged. They also fly high – usually operating several thousand feet above the cruise altitude of airliners. They’re also far easier and cheaper to maintain than a large four-engined aircraft. They also symbolise the trend in the last half-century away from the importance of the aircraft type itself and more towards the equipment onboard.

8: Boeing C-97 Stratofreighter

If you believe that Boeing’s B-29 bomber converted into an airliner modified into a tanker was just another aeroplane dripping oil on the ramp, think again. A handful of the venerable C-97s were configured with ultra-discreet intelligence systems and operated for years in plain sight. That was precisely what the US Air Force intended.

Beginning in the early 1950s, a little-known Texas organization Big Safari installed a 20 ft focal length BIG BERTHA camera in a C-97. Through the clever use of mirrors and masterful camouflage of the aircraft’s exterior, the PIE FACE C-97 was indistinguishable internally and externally from any other ‘trash hauler’ (slang for a transport aircraft).

(Photo shows standard C-97)

Based at Rhein-Main air base in West Germany, PIE FACE quickly began taking superior-quality images of Soviet and East German forces along the border. Although restricted to flying no higher than 10,000 ft, it routinely flew into Berlin along the three air corridors from the West, earning the squadron the nickname “Berlin for Lunch Bunch.”

Despite its unassuming appearance, the Soviets were keenly aware of its clandestine role. In a chance meeting between pilots after the Cold War ended, a Soviet pilot asked a C-97 pilot, “Which were you, pictures or beeps?” The C-97’s operational life as a spyplane lasted nearly 25 years. BIG SAFARI would become the world’s largest and most successful converter of aircraft into spyplanes. 

7: Lockheed EP-3

The US Navy pegs its first spot with the spooky version of its antisubmarine warfare P-3. In 1963 the CIA wanted a replacement for its RB-69s (converted P2V Neptunes) used in covert reconnaissance and insertion operations in Europe and China. By 1964 three P-3s were configured for ELINT and COMINT.

Two years later they were transferred to Taiwan’s secret Black Bat squadron. Reportedly equipped with AIM-9 Sidewinder missiles for self-defence, they flew peripheral SIGINT missions off the coast of the People’s Republic of China (PRC).

Eventually, these were returned to the US Navy and by the late 1960s became part of the small EP-3 fleet that operated in conjunction with EA-3s and EC-121s. These missions, which continue today, largely focus on maritime operations and peripheral sorties along coastal areas of interest to the US Navy.

Arguably the most famous EP-3 is the one struck by a cowboy PRC Shenyang J-8 pilot while on a peripheral sortie in April 2001 and made a forced landing on Hainan Island. The aircraft and its secret contents were explored by the Chinese and apparently made some notable discoveries, but the crew and aeroplane were all repatriated. The EP-3 has become the mainstay of US Navy long-range peacetime intelligence collection effort.

6: Douglas EA-3 Skywarrior

As the US Navy sought to increase its role in delivering nuclear strikes from carriers during the budget battles of the 1950s, the Douglas A3D emerged as a twin-engine ‘heavy’ bomber. Known variously as “the Whale” and “All Three Dead” (it lacked ejection seats), this relatively capacious aeroplane was soon carrying out ELINT missions.

This proved especially valuable as some of the most precious Soviet naval ELINT was obtainable only during short periods of intense blue-water operations (a blue-water navy is a maritime force capable of operating globally) that could not be covered by land-based aircraft.

Launching an EA-3 (and RA-3 variants) from a nearby carrier group often bagged the latest data on new shipboard missiles and radar that had cognate systems on the ground such as the SA-N-1 Goa, the same as the land-based SA-3. Several EA-3 aircraft also collected telemetry intelligence (TELINT) and communications intelligence (COMINT) associated with Soviet ballistic missile tests.

Operations included missions from Shemya AFB, AK (original home of the COBRA BALL) and British bases in the Indian Ocean. By the time VQ-2 retired its last EA-3 in 1991, it had accumulated more than three decades of maritime intelligence and peripheral ELINT collection.

5: Boeing RB-47 Stratojet

Along with the B-36, Boeing’s B-47 acquired a reputation for never having fired a shot or dropped a bomb in anger. While this may have been true of the B-47 bomber, it did not apply to the reconnaissance versions of the Stratojet.

Piston-powered RB-50s and RB-36s were vulnerable to Soviet MiG-15s, so USAF pinned their hopes on the speedy, high-flying jet B-47. Its first overflight of the USSR was a B-47B photographic intelligence mission above the Chukotskii Peninsula in October 1952, attracting considerable attention from MiGs. Another overflight was chased by dozens of MiG-15s and MiG-17s before safely returning to the UK.

The RB-47’s most significant overflight of the USSR was the HOME RUN series in early 1956. Flown from Thule AB in Greenland, 20 PHOTINT-configured RB-47Es, SLAR-equipped RB-47Es, and ELINT-configured RB-47Hs conducted 156 deep overflights of the USSR. Amazingly, none were shot down.

Between 1956 and 1967, RB-47s flew thousands of daily, routine missions from bases in the US, England, Japan, and Turkey that established and validated the routes and procedures that SAC and its successor Air Combat Command would use to the present day. It was truly the pioneer of Cold War peacetime aerial reconnaissance.

4: English Electric/Martin Canberra

If there is a grandfather of modern high-altitude, jet-powered reconnaissance aeroplanes, it would be the English Electric Canberra. When the U-2 first overflew Eastern Europe and the USSR in 1956, the Soviets misidentified it as a Canberra, attesting to its reputation as a highflyer. The Canberra PR.3 was reportedly the first purpose-built photo reconnaissance aeroplane for the RAF, entering service in 1952. By the following year, it was flying ELINT missions from West Germany over the Baltic, as well as sorties over the Black and Caspian Seas and from Iraq.

License-built by Martin in the United States as the RB-57A, a handful of these conducted high-altitude overflights of the USSR, PRC, and North Korea under programs like HEART THROB and SHORT CUT. Three heavily modified RB-57Ds conducted SAC’s last overflight of the USSR in December 1956.

Other missions included Baltic sorties and flights from Turkey. Taiwan operated RB-57Ds on overflights of China. The loss of one of these in October 1959 is believed to be the first airplane shot down by a surface-to-air missile, a lesson not fully appreciated until six months later over the USSR, as we’ll see. Further modified into the RB-57F, the “big wing Canberra” collected ELINT and PHOTINT as well as particle sampling to detect atmospheric nuclear tests.

Sweden and Pakistan were among the countries that used the Canberra or RB-57 to conduct peacetime ELINT and PHOTINT missions. The PEE WEE RB-57Fs in Pakistan also monitored Soviet ICBM tests in evaluation sorties on behalf of the US.

3: Lockheed SR-71 Blackbird

On May 1 1960, a US U-2 reconnaissance was shot down over the Soviet Union, and the pilot Francis Gary Powers was held prisoner. It was clear that high-altitude flight was no longer enough to keep an aircraft save from air defences.

Clearly, the next generation of spy plane would require extremely high speed (over Mach 3) – and a degree of radar stealth. Stealth is several technologies and techniques, then in their infancy, which reduce the distance and ease with which a hostile radar can detect an aircraft.

According to Blackbird pilot BC Thomas, “Our advantage, owing to stealth, speed, altitude, sensor operation, and defensive systems would let us be over any spot on earth at any given date and time without too much worry about being shot down.  And the pictures were good.  How can you get any better a reconnaissance aircraft than that?”

Lockheed’s SR-71 was—and remains—the ultimate aircraft used as a spyplane. Mach 3+ at 80,000 ft, exotic fuel, David Clark space suits (the same as the U-2 and RB-57 drivers wore), black, enigmatic, small fleet (32), and sure to please crowds and aviation enthusiasts everywhere surely have to count for something. And it looks deliciously sinister, frankly - though totally unarmed. Despite its 'ultimate'  status as an aircraft, as a reconnaissance asset, there are two airframes of greater historical significance and longevity. 

2: Boeing RC-135

Derived from the C-135 tanker aircraft, the RC-135 lacks the exotic appearance of some of the other aircraft on this list. It would be easy to mistake the RC-135 for an airliner, but the RC-135 is one of the most important reconnaissance aircraft in the world.

The aircraft is a veteran, having been around since 1961. RC-135s large size and endurance allow it to go almost anywhere in the world carrying both a sophisticated array of reconnaissance equipment and the crew to operate it. Though only 32 RC-135s were created they come in a bewildering array of variants for specialised missions.

RC-135s have three distinct missions: The RIVET JOINT V/Ws have an ELINT/COMINT mission. ELINT or Electronic intelligence is intelligence-gathering by electronic sensors. The purpose is often to assess the capabilities of a target, such as the location and nature of a radar), the COMBAT SENT C-135Us have a specialised ELINT mission.

The COBRA BALL Ss have a MASINT/TELINT mission. MASINT is measurement and signature intelligence which means the detection, tracking, identifying or description of the signatures (distinctive characteristics) of fixed or dynamic target sources. This often includes radar, acoustic intelligence and nuclear chemical & biological intelligence. COMINT aircraft gather information from communications, including radio communication, and telephone calls.

1: Lockheed U-2 ‘Dragon Lady’

The Lockheed U-2 has been snooping around, performing reconnaissance missions, since 1956, meaning on longevity alone it would merit a place on this list. But the U-2 is more than simply venerable, it has also been a brilliantly performing and hugely historically significant machine.

Against 1950s air defences, aircraft had to fly ever higher, and operation in the thin air of such high altitudes requires a massive wing. Designed by the US aircraft design genius Kelly Johnson, the U-2 recycled many features of the F-104 fighter but replaced the ‘104s famously tiny wing with a vast sailplane-like wing.