Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 174.2; Flight Crew Total 7982.90; Flight Crew Type 1598.62
Workload; Time Pressure; Situational Awareness; Distraction; Communication Breakdown; Troubleshooting
Aircraft Equipment Problem Less Severe
Flight Crew FLC complied w / Automation / Advisory; Flight Crew Returned To Departure Airport; Flight Crew Landed in Emergency Condition
Aircraft; Environment - Non Weather Related
I was the relief FO on the flight. Preflight was normal with the exception of a 'SLATS DRIVE' EICAS message which none of us had ever seen before. We called maintenance and they troubleshot the problem for about 30 minutes. Ultimately they were able to extinguish the EICAS message and a new flight release was issued. Taxi; takeoff; and initial climb out were uneventful and I went on first break. As I was climbing into the bunk; I was called back to the flight deck. When I arrived; we were in holding; the SLATS DRIVE message had returned; and the crew was setting up to dump fuel and return to TLV. The Captain had me run landing distance for RWY 12 for max landing weight. In general; I observed the crew manage the situation; and making sure someone was always flying the airplane; and that checklists were complete. As I joined the problem late; I verified they had issued an alert to ATC (they did; both with Nicosia control and Tel Aviv arrival). Because TLV typically jams the GPS; SATCOM was garbled but the Captain was able to communicate with Dispatch via ACARS. Arrival and landing were uneventful other than the expected Brake Temperature EICAS message which we handled per the proper checklist. (We did request vehicles who inspected us upon exiting the runway and followed us to gate.)
Arrived at gate saw unusual EICAS Slat drive message. Entered as MRM code and called TLV Operations to have maintenance come to aircraft. Maintenance worked the issue and cleared the item. Uneventful taxi and takeoff. About 90-120 miles from TLV communication with Nicosia control we got Slat Drive EICAS. We communicated to Nicosia we had a flight control issue; declared emergency and told of our intentions were to return to TLV. We requested hold and informed Nicosia we would have to jettison fuel as well. Nicosia authorized the fuel Jettison. We entered hold about 118 miles North of TLV and worked the Slat drive EICAS and the un-annunciated fuel jettison checklist. Both checklists completed successfully. It had been the FOs leg but after checklists had been completed I opted to fly the airplane back to TLV.We were within 180 miles of TLV which required us to talk to BGN control to request re-entry into their airspace and to also declare the emergency. They asked if we were a priority aircraft and we affirmed. During the hold we tried to Satcom dispatch after we had already notified them of the nature of the issues via ACARS and included our intentions. Satcom was weak so we sent ACARS to dispatch to work out our landing distance needed with our slat drive malfunction. We came up with approximately 7;000 feet runway needed and dispatch came up with 7;200.  After checklists completed and fuel jettisoned down to MLW we requested clearance to TLV. TLV offered us straight in RW 12 which we accepted. Land although fast 182kts at flaps 20 was uneventful (auto brakes 4 used) we rolled to almost end of runway for a slow uneventful turn off.We expected hot brakes and advised Tower to tell CFR trucks to inspect wheels brakes. They noted nothing and we taxied uneventfully to gate. CFR had expressed they were given only 12 minutes notice to roll trucks and wanted to know when we had actually requested priority. We explained well before contact with approach control. Final write up made at blocks was hot brakes. My crew acted like a well oiled machine great CRM; and all was included in the debrief. Dispatch was also a great help throughout the problem.
Air Carrier First Officer reported the pilot crew; during an in-flight mechanical abnormality; had difficulty communicating with dispatch. The transmission was garbled and the FO suspected it may have been caused by known GPS jamming in the TLV area.