Falcon 2000
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Flight Instructor; Flight Crew Flight Engineer
Flight Crew Last 90 Days 10; Flight Crew Total 23500; Flight Crew Type 1500
Aircraft Equipment Problem Critical; Inflight Event / Encounter Fuel Issue; Inflight Event / Encounter Weather / Turbulence
Flight Crew Diverted; Flight Crew Inflight Shutdown; Flight Crew Landed in Emergency Condition; General Maintenance Action; General Declared Emergency
Aircraft; Weather
I was the First Officer; pilot not flying; on a Falcon 2000 aircraft. While cruising at FL410 we encountered an uncommanded in-flight shutdown of the right engine. We declared an emergency; made a descent under ATC vectoring back toward [the airport]; made a visual approach and uneventful single-engine landing.The Captain elected not to try a restart. Emergency equipment at [the airport] was requested and supplied. We taxied in the FBO after landing.Subsequently; after Maintenance performed their tests and checks it was determined that the probable cause was fuel starvation due to fuel becoming too dense to pass through the fuel lines. The SAT at FL410 was -70C. That is a temperature that I have not encountered in 46 years of flying. I am a retired major airline pilot; having flown numerous airline and corporate jet aircraft; with appropriate type ratings.The engine-driven fuel pump was replaced as a precaution; though the incumbent pump tested properly. We had not been using Prist [anti ice fuel additive]. Upon checking with Falcon Jet; we were told that -70C is the limit for the airframe.It would be a good idea for the appropriate organizations to review the aircraft limitations and issue a change to the limitations if necessary.
Falcon 2000 First Officer experiences an engine failure at FL410 and diversion; that is later determined to be the result of the -70 degrees C air that they were flying in at the time.