Narrative:

We were eastbound at FL340 on north atlantic track (nat) V at approximately 50n39w when we encountered moderate turbulence which I believe was from the wake of company flight just ahead of us at FL350. Engine #1 failed and the airspeed began to decrease. Being unable to hold altitude, we declared an emergency on frequency 121.5, departed nat V to the north and began a slow descent. We contacted gander radio on the HF radio, informed them of the engine failure, our departure from the track and our descent from FL340. We also declared an emergency with gander center during this communication. During the descent we accomplished the emergency engine failure checklist and shut down engine #1. As we descended through about FL300, we restarted engine #1 and all engine indications were normal. During the deviation 30 NM north of nat V, the altitude was never below FL290. Being that we were still operating under the original emergency declaration, I thought it prudent to climb back to FL340 for the following reasons: 1) I was concerned that the additional fuel burn rate would use valuable fuel we might need later. 2) FL340 was our original altitude when we left nat V. 3) it was safe to climb since no other aircraft were reporting emergency status in the area. We advised gander radio that we were climbing back to FL340. Soon after reaching FL340, we requested and received clearance to intercept nat V. Shortly after we reported established on nat V, we received a new clearance to 51n30w and began navigating to that point. A brief time later, we received a message from gander radio that gander ATC was filing a violation report due to our climb back to FL340 without an ATC clearance. The flight continued to cdg without further incident. I believe the cause of the engine failure was the wake turbulence from the company flight only 1000 ft above us. Since the vertical separation on the nat system was only recently reduced to 1000 ft, I think a study should be done to see if other pilots have had problems with wake turbulence over the north atlantic. During the emergency, HF radio communications were very difficult. With all the technical advances in communications available, especially long distance satellite communications, it is hard to believe we are still using this 'stone-age' technology to communicate over water. Another major communications problem was that we could not talk directly to the controling facility, in this case gander center, but had to relay all communications through an intermediary (gander radio). This causes a time delay when immediacy in communications is essential. There has to be a better way to control traffic over the north atlantic. The present system is too outdated.

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Original NASA ASRS Text

Title: A DC10-40 IN CRUISE AT FL340 DECLARED AN EMER DUE TO #1 ENG FLAMEOUT. DSNDED TO FL290 AND HAD A SUCCESSFUL RELIGHT AND RETURNED TO ASSIGNED ALT.

Narrative: WE WERE EBOUND AT FL340 ON NORTH ATLANTIC TRACK (NAT) V AT APPROX 50N39W WHEN WE ENCOUNTERED MODERATE TURB WHICH I BELIEVE WAS FROM THE WAKE OF COMPANY FLT JUST AHEAD OF US AT FL350. ENG #1 FAILED AND THE AIRSPD BEGAN TO DECREASE. BEING UNABLE TO HOLD ALT, WE DECLARED AN EMER ON FREQ 121.5, DEPARTED NAT V TO THE N AND BEGAN A SLOW DSCNT. WE CONTACTED GANDER RADIO ON THE HF RADIO, INFORMED THEM OF THE ENG FAILURE, OUR DEP FROM THE TRACK AND OUR DSCNT FROM FL340. WE ALSO DECLARED AN EMER WITH GANDER CTR DURING THIS COM. DURING THE DSCNT WE ACCOMPLISHED THE EMER ENG FAILURE CHKLIST AND SHUT DOWN ENG #1. AS WE DSNDED THROUGH ABOUT FL300, WE RESTARTED ENG #1 AND ALL ENG INDICATIONS WERE NORMAL. DURING THE DEV 30 NM N OF NAT V, THE ALT WAS NEVER BELOW FL290. BEING THAT WE WERE STILL OPERATING UNDER THE ORIGINAL EMER DECLARATION, I THOUGHT IT PRUDENT TO CLB BACK TO FL340 FOR THE FOLLOWING REASONS: 1) I WAS CONCERNED THAT THE ADDITIONAL FUEL BURN RATE WOULD USE VALUABLE FUEL WE MIGHT NEED LATER. 2) FL340 WAS OUR ORIGINAL ALT WHEN WE LEFT NAT V. 3) IT WAS SAFE TO CLB SINCE NO OTHER ACFT WERE RPTING EMER STATUS IN THE AREA. WE ADVISED GANDER RADIO THAT WE WERE CLBING BACK TO FL340. SOON AFTER REACHING FL340, WE REQUESTED AND RECEIVED CLRNC TO INTERCEPT NAT V. SHORTLY AFTER WE RPTED ESTABLISHED ON NAT V, WE RECEIVED A NEW CLRNC TO 51N30W AND BEGAN NAVING TO THAT POINT. A BRIEF TIME LATER, WE RECEIVED A MESSAGE FROM GANDER RADIO THAT GANDER ATC WAS FILING A VIOLATION RPT DUE TO OUR CLB BACK TO FL340 WITHOUT AN ATC CLRNC. THE FLT CONTINUED TO CDG WITHOUT FURTHER INCIDENT. I BELIEVE THE CAUSE OF THE ENG FAILURE WAS THE WAKE TURB FROM THE COMPANY FLT ONLY 1000 FT ABOVE US. SINCE THE VERT SEPARATION ON THE NAT SYS WAS ONLY RECENTLY REDUCED TO 1000 FT, I THINK A STUDY SHOULD BE DONE TO SEE IF OTHER PLTS HAVE HAD PROBS WITH WAKE TURB OVER THE NORTH ATLANTIC. DURING THE EMER, HF RADIO COMS WERE VERY DIFFICULT. WITH ALL THE TECHNICAL ADVANCES IN COMS AVAILABLE, ESPECIALLY LONG DISTANCE SATELLITE COMS, IT IS HARD TO BELIEVE WE ARE STILL USING THIS 'STONE-AGE' TECHNOLOGY TO COMMUNICATE OVER WATER. ANOTHER MAJOR COMS PROB WAS THAT WE COULD NOT TALK DIRECTLY TO THE CTLING FACILITY, IN THIS CASE GANDER CTR, BUT HAD TO RELAY ALL COMS THROUGH AN INTERMEDIARY (GANDER RADIO). THIS CAUSES A TIME DELAY WHEN IMMEDIACY IN COMS IS ESSENTIAL. THERE HAS TO BE A BETTER WAY TO CTL TFC OVER THE NORTH ATLANTIC. THE PRESENT SYS IS TOO OUTDATED.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.