August 18, 2017:
On August 12th Russia made a point of revealing another of their post-Cold War EW (electronic warfare) aircraft. This one was called the Il-22PP and described as an airborne electronic jammer that can detect and block all manner of signals but particularly the digital ones (like Link 16) used by Western warplanes and radars like those used by AWACS aircraft. The Il-22PP was also described as being able to protect itself from anti-radiation missiles, like the American AGM-88. The most obvious defense were numerous chaff dispensers but Russia implied that its electronic defenses were formidable. At the same time Russian officials said the Il-22PP was a test model of a more advanced aircraft that would be based on a modern transport like the An-140.
The Il-22PP was announced in late 2016 when the Russian Air Force said it had received three of them. The Il-22PP was based on the Il-18D, which was an airliner that was frequently converted to Il-20 maritime and ELINT (electronic) surveillance or Il-38 ASW (anti-submarine warfare) aircraft. An Il-20 was spotted in Syria during late 2015 but apparently didn’t stay long. Most of the 700 Il-18s built between 1957 and 1985 served as airliners and transports and over a hundred are still in service. The basic aircraft was a 65 ton, four turboprop aircraft with a max speed of 675 kilometers an hour (625 for cruising). It could carry up to 125 passengers and crew or 12 tons of cargo. Max endurance was ten hours but in regular service average flight duration was under six hours.
The Il-18 based electronic warfare and surveillance aircraft were adequate at best and the Il-38 ASW aircraft (similar to the American P-3) never was able to match the P-3. This was known because India was a user and complained loudly and frequently of the Il-38s poor performance, even after they got a late 1990s update. India turned instead to the new American P-8 (the replacement for the P-3).
Since late 2015 Russia has revealed (to the public) the existence of other post-Cold War electronic warfare aircraft by using them in Syria or over Ukraine. The most prominent of these was the Tu-214R which showed up in Syria during early 2016. This is the Russian equivalent of the American RC-135 Rivet Joint. These aircraft can collect a wide variety of electronic signals in an area, and analyze them quickly and act (as in using onboard jammers). The analysis effort is looking for patterns. The enemy below leaves signs electronically (cell phones, walkie-talkies) or visually (images captured on surveillance cameras). Using the right math and analytical tools (software and computers) and you can quickly discover where the bad guys are coming from, and have the ground troops promptly shell, bomb or raid the location. This kind of work was popular with the RC-135 crews (about thirty aircrew and techies) in Iraq, Afghanistan (and elsewhere), because they were getting a chance to do, in a combat zone, what they have long trained for. Moreover, it's relatively risk free, as the aircraft fly beyond the range of machine-gun or shoulder fired anti-aircraft missiles. In addition, the most productive work is done during night missions, when the bad guys can't even see the RC-135's (or Tu-214R) high above.
Russia and China both studied the use of RC-135s in Iraq and Afghanistan and the Russian response was two Tu-214Rs. These aircraft completed their testing during 2015 and the one in Syria was getting its first combat experience. This allowed the United States and Israel to monitor the Tu-214R in action. Apparently there was nothing particularly impressive about it. Russia has not mentioned sending the Il-22PP to Syria. Russia has sent post-Cold War ground based jamming systems to Syria. The most notable of these was the truck mounted Krasukha-4 ELINT/Jammer with capabilities similar to those cited for the Il-22PP. The Krasukha-4 passive monitoring systems were apparently used but the jammer, with a range of 250 kilometers, apparently was not.