Narrative:

We had reached our cruise altitude of FL340 while still communicating with center. We were cleared direct to ZZZ intersection and then were handed off to center shortly after. We made successful contact with them. We then received clearance to fly direct ZZZ1 intersection then direct ZZZ2 intersection for the ZZZ arrival. Some time passed when we noticed a quiet radio. I made several calls on the radio with the frequency present on our radio and got no response. I consulted the charts and found a frequency for center for our current location. After tuning in 1XY.xx we discovered center had been looking for us. We checked in immediately which was acknowledged by the controller. A short time later we were requested to call a phone number provided to us for a possible pilot deviation.after successfully landing with an inflight emergency; the pilot flying made the phone call as requested. We were informed of the following: we were switched from 1XX.xx to 1YY.xx -and we acknowledged; we never checked in on 1YY.xx; ATC tried contacting us without success; several attempts were made by ATC to contact us without success; after contact was successfully reestablished on 1XY.xx; a total of 26 minutes of lost communication had elapsed; no conflict had resulted from the event.when we as a crew debriefed how this event could have possibly occurred; we thought of some possibilities and factors that could have caused this error [including little traffic and the possibility of mishearing/not hearing a frequency change].in the climb to cruising altitude; I noticed the left engine (#1 engine) appeared to have a higher itt with a lower N1 speed than the right engine (#2 engine). This observation did not alarm me as there is usually a discrepancy between engines. After reaching cruise altitude; I performed the standard cruise checklist. The #1 engine appeared to have the same discrepancy. I performed a trend monitoring sheet on both engines after an hour of flying. This is when the performance of our number 1 engine became a little concerning but not too alarming as oil pressure and temps were observed to be slightly higher than usual but well within limits. At this time; I brought up my concerns to the other pilot. We adjusted the throttle of the #1 and observed oil pressure near the top of the green arc on our gauge; but well within limits. We reviewed past trend reports that were in our flight book and definitely observed higher than usual temps in both the oil and itt and higher than usual oil pressure (all were within limits). We discussed possible causes including the possibility of faulty indications. We documented our observations with photos taken with an i-phone with the intention of notifying our maintenance personnel upon landing. We continued to make adjustments with the #1 throttle to keep the indications well within operating parameters and closely monitored all gauges in the cockpit. We reviewed checklists in the attempt to find a remedy for the unusual indications. Did our attention and focus become too narrowed to one aspect of the flight causing us to not complete the radio handoff? Very possible. Was there some sort of radio failure or signal interruption during this time? Possible; but unlikely. Any one singular factor or possibility or any combination of them could have led to this occurrence to have happened. As a note; upon descent the oil pressure became erratic and the cabin rapidly filled with smoke. We initiated emergency procedures and were successful in cutting off the engine; securing it; eliminating the smoke; and landed without incident with only the #2 engine operating. Also; upon debriefing; we will attempt to devise new techniques or procedures to eliminate the possibility of communication mistakes with ATC or faster recognition if one is to occur.

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Original NASA ASRS Text

Title: A Falcon 2000 flight crew; after struggling with a loss of communications with ATC enroute to the U.S.; suffered erratic oil pressure in the left engine and had the cabin fill with smoke as they approached their destination. They declared an emergency; shut down the engine which eliminated the smoke and landed uneventfully thereafter at their planned destination.

Narrative: We had reached our cruise altitude of FL340 while still communicating with Center. We were cleared direct to ZZZ intersection and then were handed off to Center shortly after. We made successful contact with them. We then received clearance to fly Direct ZZZ1 intersection then Direct ZZZ2 intersection for the ZZZ Arrival. Some time passed when we noticed a quiet radio. I made several calls on the radio with the frequency present on our radio and got no response. I consulted the charts and found a frequency for Center for our current location. After tuning in 1XY.XX we discovered Center had been looking for us. We checked in immediately which was acknowledged by the controller. A short time later we were requested to call a phone number provided to us for a possible pilot deviation.After successfully landing with an inflight emergency; the pilot flying made the phone call as requested. We were informed of the following: we were switched from 1XX.XX to 1YY.XX -and we acknowledged; We never checked in on 1YY.XX; ATC tried contacting us without success; Several attempts were made by ATC to contact us without success; After contact was successfully reestablished on 1XY.XX; a total of 26 minutes of lost communication had elapsed; No conflict had resulted from the event.When we as a crew debriefed how this event could have possibly occurred; we thought of some possibilities and factors that could have caused this error [including little traffic and the possibility of mishearing/not hearing a frequency change].In the climb to cruising altitude; I noticed the left engine (#1 engine) appeared to have a higher ITT with a lower N1 speed than the right engine (#2 engine). This observation did not alarm me as there is usually a discrepancy between engines. After reaching cruise altitude; I performed the standard CRUISE checklist. The #1 engine appeared to have the same discrepancy. I performed a trend monitoring sheet on both engines after an hour of flying. This is when the performance of our number 1 engine became a little concerning but not too alarming as oil pressure and temps were observed to be slightly higher than usual but well within limits. At this time; I brought up my concerns to the other pilot. We adjusted the throttle of the #1 and observed oil pressure near the top of the green arc on our gauge; but well within limits. We reviewed past trend reports that were in our flight book and definitely observed higher than usual temps in both the oil and ITT and higher than usual oil pressure (All were within limits). We discussed possible causes including the possibility of faulty indications. We documented our observations with photos taken with an I-phone with the intention of notifying our maintenance personnel upon landing. We continued to make adjustments with the #1 throttle to keep the indications well within operating parameters and closely monitored all gauges in the cockpit. We reviewed checklists in the attempt to find a remedy for the unusual indications. Did our attention and focus become too narrowed to one aspect of the flight causing us to not complete the radio handoff? Very possible. Was there some sort of radio failure or signal interruption during this time? Possible; but unlikely. Any one singular factor or possibility or any combination of them could have led to this occurrence to have happened. As a note; upon descent the oil pressure became erratic and the cabin rapidly filled with smoke. We initiated emergency procedures and were successful in cutting off the engine; securing it; eliminating the smoke; and landed without incident with only the #2 engine operating. Also; upon debriefing; we will attempt to devise new techniques or procedures to eliminate the possibility of communication mistakes with ATC or faster recognition if one is to occur.

Data retrieved from NASA's ASRS site 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.