The incident occurred July 18, 2014 while flying in international airspace. The aircraft was conducting an eavesdropping mission on the Russian military. During the flight the aircraft started being tracked by Russian ground based radar.
Sometime during the incident at least one Russian fighter was dispatched to respond to the RC-135. The US aircraft countered by entering Swedish airspace, but did so without permission. The US has since apologized for the incident, but has also informed the Swedish government that future incident may occur should similar incidents happen with the Russian military in the area.
It is not entirely uncommon for aircraft from other nations to encounter each other in border areas, but is less common for ground based radar to begin tracking the aircraft. US and Russian aircraft have somewhat routinely encountered each other.
The situation between the US and Russia continues to show further strain as Russia has continued to support Ukrainian separatists and may in fact have stepped up efforts supporting them. It also comes on the heels of the downing of Malaysian Airlines MH-17. Some are seeing this as a return to the cold war as Russian President Vladimir Putin is seen as continuing to flex Russian military and diplomatic muscle.
U.S. official: Spy plane flew over Sweden to evade Russian military tracking
http://www.cnn.com/2014/08/02/us/us-spy-plane/index.html
U.S. military plane entered Swedish airspace without permission
Characteristics of the RC-135 Rivet Joint
Mission
The RC-135V/W Rivet Joint reconnaissance aircraft supports theater and national level consumers with near real time on-scene intelligence collection, analysis and dissemination capabilities.
General Characteristics
Primary Function: Reconnaissance
Contractor: L-3 Communications
Power Plant: Four CFM International F108-CF-201 high bypass turbofan engines
Thrust: 21,600 pounds each engine
Wingspan: 131 feet (39.9 meters)
Length: 135 feet (41.1 meters)
Height: 42 feet (12.8 meters)
Weight: 173,000 pounds (78,743 kilograms)
Maximum Takeoff Weight: 297,000 pounds (133,633 kilograms)
Fuel Capacity: 130,000 pounds (58,967 kilograms)
Speed: 500+ miles per hour (Mach.66)
Range: 3,900 miles (6,500 kilometers)
Ceiling: 50,000 feet (15,240 meters)
Crew: (flight crew) five (augmented) – three pilots, two navigators; (mission flight crew) 21-27, depending on mission requirements, minimum consisting of three electronic warfare officers, 14 intelligence operators and four inflight/airborne maintenance technicians
Unit Cost: unavailable
Initial operating capability: January 1964
Inventory: Active force, 17; Reserve, 0; Guard, 0
Characteristics information extracted from: http://www.af.mil/AboutUs/FactSheets/Display/tabid/224/Article/104608/rc-135vw-rivet-joint.aspx
