B757-200
Flight Crew Last 90 Days 180; Flight Crew Total 6500; Flight Crew Type 4000
Aircraft Equipment Problem Critical; Deviation - Speed All Types
Air Traffic Control Issued New Clearance; Flight Crew Diverted; Flight Crew Landed in Emergency Condition
Aircraft
I was the relief pilot on this ferry flight with a Captain and First Officer; no other passengers or crew were aboard. The First Officer was on break and I was sitting in the right seat as the flying pilot. During cruise at FL400; I noticed our airspeed decaying significantly. I applied max thrust to the engines and arrested the airspeed from slowing further. We realized the right engine was indicating very low on the EPR gauge; near a flight idle setting; despite having the trust lever in the full forward position. The right engine gauges then began to surge wildly from a flight idle position to approximately 55-60 N1. We initiated a right turn to offset 15 NM right of the track; announced our intentions on the radio. The right thrust lever was placed in the flight idle position to prevent the engine from surging. The Captain instructed me to focus on flying the airplane and then called the First Officer from break to assist with the QRH. The Captain and First Officer communicated with ATC to facilitate a clearance to the nearest suitable airport. I was able to avoid traffic and slowly descend to FL290 initially. Eventually we obtained clearance from ATC at FL280. After completion of the QRH the First Officer sat in the right seat and I manned the cockpit jump seat for the eventual landing by the Captain.
B757 relief pilot experienced airspeed loss then engine surging at FL400 during an oceanic crossing. The crew retards the thrust of the surging engine; turns off track; and descends then receives ATC clearance to the nearest suitable alternate.