An RC-135 Rivet Joint SIGINT aircraft in flight. An encounter between a U.K.-based RC-135 and Russian fighters last month forced the USAF crew to divert into Swedish airspace (USAF photo via the U.S. Naval Institute).
Call it a hunch, but there may be more than meets the eye in last month’s encounter between an Air Force RC-135 reconnaissance aircraft and Russian fighters.
It was recently revealed that a Rivet Joint SIGINT platform darted into Swedish airspace to escape a Russian SU-27 Flanker sent up to intercept it. The incident occurred over the Baltic, just one day after Russian separatists shot down a Malaysian jetliner over eastern Ukraine.
First, a little background: Rivet Joint aircraft have been collecting various forms of electronic intelligence outside Russian airspace for decades, and they are routinely intercepted by air defense fighters. RC-135 flight paths are highly predictable, and so are the intercept points, to some degree. Collectively, they form an aerial ballet that plays out on a regular basis in the skies above the eastern Pacific; the Black Sea, the White Sea and the Baltic, among other locations.
Missions over the Baltic present special challenges; the RC-135 is supposed to remain in international airspace as it approaches Russian territory, avoiding the air defense zones of Norway, Sweden, Denmark, Norway, Poland, Finland, the Baltic States and, of course, Russia. While the National Security Agency has agreements with all allied nations in the region (and some outside NATO), none of those countries want to be directly involved in the Rivet Joint missions, to avoid complicating relations with Moscow.
Suffice it to say, RC-135 crews are very cognizant of international borders, airspace boundaries and other demarcation lines along the Baltic and do their best to avoid them. Of course, there are some exceptions, including exercises with NATO partners, or special orbits implemented in response to specific events. Earlier this year, for example, the U.S. began staging RJ missions over Romania, in response to Russian-backed aggression in the Crimea.
That’s why it was surprising the USAF SIGINT aircraft entered Swedish airspace in response to the Russian intercept attempt. The Pentagon has released few details on the incident, only acknowledging that the RC-135 entered Sweden’s airspace and that future transits would be coordinated more closely.
According to a report from Voice of America, officials at U.S. European Command said the intelligence platform was “incorrectly” directed towards Swedish airspace as it tried to avoid the approaching Russian jets.
Two points worth remembering: first, each Rivet Joint “cockpit crew” includes not one, but two navigators, for the expressed purpose of keeping the aircraft on course and out of hostile airspace. Many RJ navigators are highly experienced, with significant flight time in other platforms before transitioning to the RC-135.
Experience levels are typically even higher among the “back end” crew, comprised of linguists and other intelligence specialists, who are a part of the USAF Intelligence, Surveillance and Reconnaissance Agency (the front enders belong to Air Combat Command). As part of their mission, the intelligence crew–along with onboard electronic warfare officers–collect against designated targets AND monitor the response of adversary air defenses. If the reaction proves highly unusual or provocative, the mission is aborted, just as it was last month. Criteria for mission termination due to threat reaction vary from theater to theater; not surprisingly, the lowest threshold for that type of abort is associated with missions flown against North Korea. Given Pyongyang’s unpredictability–and past attacks against reconnaissance aircraft–RJ crews are instructed to cease collection and bug out with very little provocation from the DPRK.
Termination criteria for missions against Russia are a bit higher; in other words, it takes more consequential posturing, actions or statements to prompt mission termination against Russian targets. One reason? Historically, Russian intercepts conducted over international waters have been predictable and professional, so it’s rare for an RC-135 mission to be aborted because of a Russian reaction that appears out-of-the-ordinary.
It’s also worth noting that the RJ crew is not alone in gauging adversary response to the collection mission. Whenever an RC-135 is on a “real-world” mission, it is in direct communication with SIGINT nodes on the ground that provide “flight following” support. The decision to divert through Swedish airspace was likely made in concert with authorities on the ground, and likely in response to unusual behavior on the part of the Russians.
Essentially, there are two explanations for last month’s encounter over the Baltic. First, there’s the chance that the crew (along with support elements on the ground) made a terrible call in their interpretation of Russian intentions and grossly over-reacted. The odds of that scenario are extremely slim, given the experience of the flight and mission crews, and SIGINT support elements assigned to the mission.
A more likely explanation is that Russia decided to play tough on the day after the MH 17 shoot down, displaying actions that forced the RJ crew to terminate their mission and take the extraordinary step of diverting into Swedish airspace. Unwilling to ruffle Russian feathers any further, the administration seems to be blaming the incident on crew judgment and inappropriate guidance. The men and women who fly RC-135s aren’t perfect, but in our experience, they are exceptionally professional. The odds of a “mistake chain” like the one described are extremely slim. On the other hand, if your RC-135 is locked on by
ADDENDUM: Violations of Swedish airspace occur on a regular basis; and sometimes, the offending aircraft belong to–you guessed it–the Russians.
Additionally, a spokesman at EUCOM says the RJ crew–and support elements on the ground–followed “all appropriate procedures” during the incident. That statement offers more support for the theory that Russian pilots (or their commanders) may have been planning something something confrontational or even deadly in the skies off the Baltic coast.