C560 CREW CLBED ACFT TOO HIGH FOR THE ACFT GROSS WT; GOT ON THE BACK SIDE OF THE PWR CURVE; AND WITH SLOWING AIRSPD; HAD TO DSND TO PREVENT A STALL IN ZME CLASS A.

Narrative

I DID DEPART ZZZ AT OR ABOUT XA00 CST. THE FLT WAS CONDUCTED UNDER FAA PART 91 RULES AND REGULATIONS. A CURRENT AND COMPLETE WX BRIEFING WAS OBTAINED; AND THIS FLT WAS CONSIDERED TO BE A COMPLETELY SAFE AND NORMAL OP. IF IT WAS SOMETHING ELSE; THE ACFT WOULD NOT HAVE DEPARTED. THE ACFT'S WT AND BAL WAS CONSIDERED; AND WE WERE AT LEAST 1000 LBS UNDER MAX GROSS WT. ADVANCING TIME-WISE INTO THIS FLT; AT OR ABOUT 30 MINS AFTER DEP; MEM ARTCC HAD CLRED CESSNA CITATION DIRECT TO ZZZ1 TO CLB AND MAINTAIN FL410. ZME ADVISED ME TO BE LEVEL AT FL410 WITHIN 2 OR 3 MINS. AT THIS TIME; I HAD THE ACFT CLBING AT 1000 FT PER MIN; AND I WAS PASSING FL402. THE ACFT HAD BEEN CLBING QUITE WELL; AND I HADN'T ANTICIPATED ANY LESS CLB THAN 500 FPM; WHICH WOULD HAVE PUT ME LEVEL AT FL410 AT OR LESS THAN THE TIME REQUIRED BY ZME. UPON PASSING FL408; THE ACFT STARTED TO SLOW IN ITS CLB; AND THE AIRSPD DECELERATED. I DROPPED THE NOSE A LITTLE; AND LET THE ACFT ACCELERATE. I STOPPED CLBING AT FL410; AND THE AIRSPD CONTINUED TO DECELERATE. OF COURSE; MY THOUGHTS WERE; ONCE THE ACFT LEVELS OFF THE AIRSPD WOULD PICK UP; AND THAT WOULD BE THAT. AT FL410; THE ACFT KEPT DECELERATING; AND I FELT AND HEARD A RUMBLING COMING FROM THE REAR OF THE ACFT. AT THIS TIME; I DISENGAGED THE AUTOPLT AND HAND FLEW THE PLANE; SO I COULD FEEL IT BETTER. THE ANGLE OF ATTACK INDICATOR CONFIRMED MY SUSPICION THE ACFT WAS APCHING A STALL. I AM AN INSTRUCTOR AND A CHK AIRMAN IN THE CESSNA CITATION ACFT FOR AN FAA PART 135 COMPANY; AND HAVE EXPERIENCED THIS WHEN I HAVE BEEN TRAINING OTHER PEOPLE. UPON SEEING WHAT WAS HAPPENING; I ASKED FO TO CONTACT ZME. FREQ WAS QUITE CONGESTED WITH TFC. I HAD NOTICED THAT FO WAS HAVING TROUBLE GETTING THROUGH TO ZME. AT THIS TIME; I TOLD FO THAT WE NEEDED TO DECLARE AN EMER; BECAUSE I COULD NO LONGER MAINTAIN FL410. THE RUMBLE WAS GETTING LOUDER; AND THE ANGLE OF ATTACK INDICATOR WAS GETTING CLOSER TO THE STALL POINT. AT THAT TIME; I BELIEVE THAT I PERSONALLY GOT ON THE RADIO AND TOLD ZME WE NEEDED TO MAKE A CHANGE; BECAUSE WE COULD NOT MAINTAIN FL410. WE HAD THE ACFT'S TCASII OPERATING; AND THE INST ADVISED US THAT NO TFC WAS TO THE N OF US. ZME ADVISED US THAT HE COULD NOT GIVE US LOWER DUE TO ONCOMING TFC AT FL390. ZME GAVE US A TURN TO THE N AND GAVE US A LOWER ALT. THE CITATION'S NOSE WAS LOWERED AND ZME ADVISED US THAT THE TFC WAS NO LONGER A FACTOR. I BELIEVED THE MAX ALT LOSS WAS 400 FT LOW. ZME ADVISED US TO CALL THEM UPON ARR. I TALKED TO THE ZME SUPVR. THE FIRST THING OUT OF HIS MOUTH WAS THAT I HIT THAT WARM FRONT AND THE ACFT HAD LOST SOME OF ITS PERFORMANCE. HE ADVISED THAT HE RECEIVED SOME COMMENTS EARLIER THAT DAY ABOUT IT. I TOLD HIM WHAT HAD HAPPENED; AND HE UNDERSTOOD. HE ADVISED ME THAT; DUE TO THE AUTOMATIC DETECTOR THAT WENT OFF; HE HAD TO FILE A RPT. I TOLD HIM THAT I UNDERSTOOD; AND THAT I WAS AN AIR TFC CTLR IN THE MIL AT ONE TIME; AND I KNEW HOW THE SYS WORKED. IT WAS ALWAYS MY INTENTION TO MAINTAIN FL410; BUT THE ACFT (DUE TO ENTERING THE WARM FRONT) WOULD NOT STAY AT THE ALT. BY NO MEANS DID I MEAN TO DSND OUT OF MY ALT; BUT I DID HAVE TO LOOK AT MY PRIORITIES WHICH WERE FLY THE ACFT; AND KEEP THE ACFT FROM STALLING; AVOID OTHER TFC; AND THE TERRAIN. THEN I NEEDED TO TELL THE APPROPRIATE AIR TFC CTLR ABOUT THE PROB; OR CHANGES THAT NEEDED TO BE MADE; TO KEEP THE FLT AS SAFE AS POSSIBLE. THERE IS NO DOUBT IN MY MIND THAT THE FLT CREW HANDLED THESE 3 ITEMS AS BEST AS ANYONE COULD. WE WERE CLRED DIRECT TO DEST; AND ZME GAVE US THE ALT WE WANTED; SO WE HAD NO REASON TO TURN OR DSND IF WE DID NOT HAVE TO.