With an increase in engine thrust by 150%, the F-4X would have featured dash speeds of Mach 3.2, cruise at Mach 2.4, and flight up to 78,000ft (23,775m) altitude
In the years leading up to the October 1973 Yom Kippur War, Israel invested significantly in building a powerful strike force made up of four F-4E Phantom/Kurnass squadrons. Over the course of nineteen days in one of the most intense and brutal modern wars, these units flew more than 3,000 sorties, claimed over 80 air-to-air victories, and lost more than 30 aircraft.
Although the F-4 was highly capable in both air-to-ground and air-to-air missions, the Israeli Air Force (IAF) continued to rely heavily on its Mirage III and Nesher delta-wing fighters for air combat. As a result, the Phantom II was employed primarily in the ground-attack role.
In addition to the F-4Es, the IAF also acquired several RF-4 reconnaissance variants. These aircraft were a valuable enhancement to Israel’s intelligence-gathering capabilities. Their combination of speed, range, and advanced camera systems enabled more complex reconnaissance missions to be carried out with lower risk to crews and aircraft than had been possible with the Mirage and Vautour fleets. As Bill Norton notes in his book Air War On The Edge: A History of the Israel Air Force and its aircraft since 1947, the IAF was only the second air arm to operate the RF-4, and its examples were the first configured to carry AIM-9 missiles for self-defense using twin-rail wing pylons, while still retaining their bombing systems. As was typical for RF-4s, the IAF’s reconnaissance Phantoms were also fitted with aft fuselage ejector units for photo-flash cartridges to support night operations. These reconnaissance aircraft were assigned across most of the F-4 squadrons.
According to Norton, “During the War of Attrition, recce aircraft were important assets in keeping track of the Egyptian missile boxes and locating targets for follow-up strikes. Photo reconnaissance was especially critical immediately following the War of Attrition. The cease-fire terms required that Egypt freeze its missile batteries in place and not continue to move SAM boxes closer to the Canal. These terms were very important to Israel, and very hazardous recon flights were made to verify compliance and then monitor movement when the cease-fire terms were clearly violated. Flights into the area were made at 600 kts and at such a low altitude that the major hazard was from bird strikes and hitting fishing boat masts.”
Even though the IAF had ordered RF-4Es, they did not start arriving until February 1971, and they flew their first mission on March 9. To fill this critical gap, two IAF F-4Es (tail numbers 17 and 19) were rapidly modified in-country over a two‑month crash program so a camera could be installed in the nose. The gun was removed, and environmental and electrical systems were adapted to allow the installation of either a Zeiss RMK 15/23 medium‑altitude mapping camera or a Fairchild KA‑52 low‑altitude panoramic camera. These two aircraft began flying operational missions with 69 Squadron on March 24, 1970, and were later transferred to 201 Squadron by September. This Israeli initiative may have sparked rumors that the U.S. had loaned Israel two RF‑4Cs between August 1970 and March 1971 under Operation Night Light (or Peace Night Lite), for which Israel supposedly paid $143,000. During their brief service, these aircraft were said to have been flown by 69 Squadron.
As Norton says, “It has been suggested that Israel had a much earlier exposure to the RF-4. One source asserts that the crews and aircraft of the USAF’s 38th Tactical Reconnaissance Squadron were deployed from Spain to Israel—probably Hatzerim—to provide their services during the Six-Day War. The RF-4Cs were supposedly given IAF markings and operated in the area until Jun. 12. While the American administration had certainly begun to lean towards the Israeli side in the Middle East conflict by 1967, this kind of material assistance during wartime was very unlikely. The IAF could certainly have used the help, freeing up their reconnaissance planes for strike missions. Another book records an even more unlikely event in 1962 when what may have been Israeli pilots collected a number of USN F-4Bs at Wheelus AB in Libya and flew them to an undisclosed location in the east. There has also been an extraordinary claim made that the U.S. Navy provided carrier landing training in the Red Sea to some 100 IAF F-4 aircrew in 1971.”
Before long, the SAM batteries were seen being pushed closer to the front. Yet this development was not welcomed by the U.N., the U.S., or many in Israel, due to fears it could trigger renewed fighting. The U.S., in particular, was determined that nothing should disrupt the planned Geneva peace talks, so no immediate steps were taken.
The RF-4Es demonstrated their value the following summer, when two of them—one flown by Aviem Sella—raced over southern Syria for 20 minutes to capture the first clear images of mobile SA-6 batteries. The mission followed months of detailed planning and training, and because it took place on a holiday without fighter cover or electronic countermeasures, it went completely unchallenged by Syrian defenses.
The dangers of these operations were obvious, as shown in October 1971 when one RF-4 landed with an SA-7 missile lodged in one of its engines. In April 1973, the IAF began flying high-altitude reconnaissance missions with their RF-4s, which required the crews to wear pressure suits.
Norton explains that the photo intelligence produced by the IAF’s high-speed RF-4Es was so crucial that the air force looked for ways to preserve this vital capability as overflights of targets became increasingly dangerous. The IAF became interested in the American 1,228 lb (557 kg) CAI KA-90 HIAC-1 ultra–long focal length (66 in/168 cm) Long Range Oblique Photography (LOROP) camera. This advanced system could distinguish an object just 10 in (25 cm) in size from 20 nautical miles away, enabling Israel to observe activity near its borders without actually crossing into neighboring territory. Israel sought to acquire one or more American RB-57F aircraft adapted to carry this camera, but the United States rejected these requests.
General Dynamics (GD) eventually produced a podded 1,500 lb (680 kg) variant of the camera, designated G-139. The system was housed in a huge 22 ft (6.7 m) pod capable of carrying 4,000 lb (1,814 kg) of equipment, including its environmental control unit. In 1971, the U.S. Congress approved the export of the G-139 to Israel, and the pods were delivered that October. The G-139 was mounted on the centreline of RF-4s and on two specially modified F-4Es, and is known to have been used by at least 119 Squadron. However, the duration of its operational service remains uncertain.
The IAF considered the system highly effective, but the drag from the large pod reduced the Phantom’s performance to an unacceptable level for combat operations. Reportedly, it capped the aircraft’s ceiling at 50,000 ft (15,240 m) and limited its top speed to just under Mach 1.5. Although flying higher would have produced better imagery, the reduced performance left this costly and specialized asset dangerously vulnerable to enemy fighters and prolonged exposure to fixed anti-aircraft defenses.
Norton explains, “To answer the limitations imposed by the G-139, GD began work to boost the performance of the F-4 engines with a series of airframe modifications under a program named Peace Jack. In 1971, the Israelis were invited to participate in the American effort. The Peace Jack airframe was initially to have included a radically revised inlet design and special low-drag external ‘saddle’ tanks. The latter, including pumps, were to provide fluid for an engine pre-compressor cooling (PCC) water injection system to cool the intake air and increase overall engine mass flow. The two 2,500lb-capacity (1,134kg) tanks were to be mounted atop the jet, between the inlet ducts and the spine of the fuselage. These changes would, in theory, have increased engine thrust by 150% to allow dash speeds of Mach 3.2, cruise at Mach 2.4, and fly up to 78,000 ft (23,775 m) altitude. The conceptual aircraft was tentatively identified as the F-4X, but no actual airframe ever bore this designation.”
“By 1974, a reduced-size and weight LOROP camera had been designed that could be enclosed in a revised F-4 nose cavity lengthened by 12 in (30.5 cm) for 70 ft3 (2 m3) of volume. The nose included two windows on the bottom quadrant and two on either side. The entire camera could be rotated to view from any one of these windows. A separate environmental control system in the nose maintained the camera within an optimal temperature range. The design was termed the RF-4X, but, again, no actual aircraft was identified with this designation. The IAF provided F-4E 69-7576 in December 1974 to General Dynamics at Fort Worth, Texas, which, over the next five months, served as the basis for a mock-up of the envisioned modifications. The combination was calculated to have allowed a Mach 2.7 cruise speed.”
Up to this stage, Israel had been sharing costs with the USAF on the Peace Jack program, but the U.S. eventually pulled out. With at least another year of development ahead and an urgent need for an operational HIAC capability, the Israelis decided to press on alone. The IAF could only afford to finance the camera installation itself, so the effort was refocused solely on that objective, abandoning the saddle tanks and the PCC. This configuration was designated F-4E(S), with the “S” standing for “Special.”
The IAF added a separate, vertically mounted KS-87 camera behind the HIAC, and the large nose could accommodate various other optical sensors. Over time, the air force almost certainly developed additional sensor packages for this space. A special sight, mounted on one or both canopy sills, helped ensure that the target area lay within the cameras’ oblique field of view.
Two additional IAF F-4Es (69-7567 and 69-7570) joined aircraft 69-7576 in Fort Worth for conversion. The F-4E(S) made its first flight on December 20, 1975, and the first of the three modified jets was handed over on July 30, 1976, with the remaining aircraft delivered soon afterward to 199 Squadron.
While in Texas, the aircraft had their noses painted to look as though they still carried standard black radomes in order to hide the modifications. According to Norton, after they returned to Israel, the (S) aircraft were kept under extremely tight security until 1998. By the late 1980s and into the 1990s, they may have shifted more toward an electronic warfare role, and they are known to have been fitted with Elta jamming equipment, including the EL/L-8230 internal system.
Photo by Lockheed Martin, Israeli Air Force, and Bukvoed via Wikipedia
