Date: 201504
Location: UHHH.ARTCC, FO
Flight conditions: VMC
Aircraft: B747 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
ATC / advisory: Center UHHH
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness
Second reporter function: First Officer; Pilot Not Flying
Anomaly: Conflict Airborne Conflict; Deviation - Altitude Excursion From Assigned Altitude
Detector: Automation Aircraft RA; Person Flight Crew
When detected: In-flight
Result: Flight Crew Became Reoriented; Flight Crew Took Evasive Action
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: We were following a B-747. Over HEK; we were directly above them by 2000 feet. I heard them accept a new clearance but did not hear what it was. We then saw them start a climb. We also expected them to stop at 37;100 feet but they continued to climb which set off our TCAS. I responded by clicking off the auto pilot and started a climbing right turn (there was also a slight course change over HEK) Our level off was 38;400 when we noticed the B747 started a descent to 36;000 feet; then 34;000 feet shortly thereafter. During the event; we told ATC we were in an RA-resolution advisory at which time ATC questioned the B747 crew on their altitude. I believe the aircraft came within 600-700 feet of us.


Second narrative: We had just climbed from FL380 to FL381 (11;600 meters). We were still with Khabarovsk Control. We got a TCAS traffic advisory (TA) off of a B747 as they climbed through FL371. As they climbed through FL373 we got a TCAS resolution advisory (RA) to climb. The pilot flying disconnected the autopilot and followed the avoidance bars on the PFD. I (the pilot monitoring) made a call to ATC that we were following a TCAS RA. I don't remember if I said 'RA' or 'resolution advisory.'  TCAS called for a stop to the climb at FL384. We leveled off at that altitude while Khabarovsk control communicated with the B747 crew and told them that they were cleared to 11;000 meters (FL361). They had leveled off at FL376; then descended back down to FL361. After the B747 was below FL370; we descended back down to FL381. Also; we then put in a 1 NM right offset to keep us from being directly above them. Shortly after this event we were handed off to Harbin control in China.During the event I believe the closest our two aircraft got was about 600 to 700 feet of vertical separation. On the ND it appeared that the B747 was directly below us. They had been at FL360 for several hour previous to this event. We had been behind them since we were in Canada. A couple of hours before the event we had climbed from FL340 to FL380. At the time we climbed; we were about 40 NM behind the B747. We slowly overtook them and were directly above them over HEK VOR.


Synopsis: B747 flight crew reports another B747 which they had been following through Russian airspace for many hours; suddenly starts climbing into them after receiving a clearance. A TCAS RA is triggered and the reporters crew begins climbing in response. Khabarovsk Control issues another clearance indicating that the triggering B747 had climbed in error.