Narrative:

In cruise flight at FL470, aircraft encountered an isa temperature increase of 6-10 degrees C. Aircraft lost a substantial amount of mach and true airspeed in a short period of time. Aircraft requested a descent due to these indications. Center was unable to approve, due to traffic. Aircraft requested a vector for descent, still was unable to get a descent clearance. Aircraft was advised the only way to get a descent was to declare an emergency. Aircraft advised ATC of the necessity to descend, again, at that point being unable to maintain altitude, and started to descend without declaring an emergency. Upon reaching FL467, ATC issued a descent to FL450. Aircraft leveled at FL450, regained mach and TAS. The flight continued uneventfully. ATC was not cooperative to a situation that was abnormal and was deteriorating due to circumstances beyond control of the flight crew.

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Original NASA ASRS Text

Title: LJ31 CREW CLBED ACFT TOO HIGH FOR THE ACFT GROSS WT, WITH A TEMP INCREASE, GOT ON THE BACK SIDE OF THE PWR CURVE, AND WITH SLOWING AIRSPD, HAD TO DSND TO PREVENT A STALL IN ZDC CLASS A.

Narrative: IN CRUISE FLT AT FL470, ACFT ENCOUNTERED AN ISA TEMP INCREASE OF 6-10 DEGS C. ACFT LOST A SUBSTANTIAL AMOUNT OF MACH AND TRUE AIRSPD IN A SHORT PERIOD OF TIME. ACFT REQUESTED A DSCNT DUE TO THESE INDICATIONS. CTR WAS UNABLE TO APPROVE, DUE TO TFC. ACFT REQUESTED A VECTOR FOR DSCNT, STILL WAS UNABLE TO GET A DSCNT CLRNC. ACFT WAS ADVISED THE ONLY WAY TO GET A DSCNT WAS TO DECLARE AN EMER. ACFT ADVISED ATC OF THE NECESSITY TO DSND, AGAIN, AT THAT POINT BEING UNABLE TO MAINTAIN ALT, AND STARTED TO DSND WITHOUT DECLARING AN EMER. UPON REACHING FL467, ATC ISSUED A DSCNT TO FL450. ACFT LEVELED AT FL450, REGAINED MACH AND TAS. THE FLT CONTINUED UNEVENTFULLY. ATC WAS NOT COOPERATIVE TO A SIT THAT WAS ABNORMAL AND WAS DETERIORATING DUE TO CIRCUMSTANCES BEYOND CTL OF THE FLC.

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.