AN MD83 OPERATING IN EXTREME COLD CONDITIONS RPTS LIMITED PITCH CTL ON TKOF AND LNDG.

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HOW COLD IS TOO COLD? MY MD83 IS CERTIFIED FOR -54 DEGS C ON THE GND AND -76 DEGS C ENRTE. HOWEVER; IT DID NOT OPERATE VERY WELL AT -41 DEGS C IN FAI. LEG #1 SEA-ANC --NO ABNORMALITIES OBSERVED. LEG #2 ANC-FAI -- TKOF WT 134.0; LNDG WT 129.5; CRUISE ALT FL280; BLOCK TIME 52 MINS; FAI WX: 1/4 FREEZING FOG; TEMP 041 DEGS C; AVERAGE RVR 1200+ FT. APCH: CAT IIIA RWY 1L. NOTHING ABNORMAL OBSERVED. LNDG: AUTOPLT DISCONNECTED DURING FLARE MODE AT OR JUST PRIOR TO TOUCHDOWN PRODUCING A FIRM TOUCHDOWN. ROLLOUT WAS DONE MANUALLY. MAINT WAS NOTIFIED OF UNSUCCESSFUL AUTOLAND DFGC -- 2. DURING THE AUTOLAND; THE FLARE AND PITCH ATTITUDE LOOKED PROPER; BUT AT DISCONNECT THE NOSE AGGRESSIVELY PITCHED DOWN. ANALYZING THE EVENT SHOWED SUFFICIENT TRIM AVAILABLE AND NO OTHER APPARENT PROBS -- SO I THOUGHT. LEG #3 FAI-ANC -- TOTAL GND TIME IN FAI WAS 33 MINS. BLOCK TO AIR 46 MINS. FAI WX: 1/4 FREEZING FOG; TEMP -41 DEGS C WITH NO PRECIP RPTED. DURING TAXI OUT; ALL FLT CTLS WERE CHKED AND CYCLED NUMEROUS TIMES. ELEVATOR TRIM WAS RESET AND MOVED FREELY. ELEVATOR CHK SHOWED PROPER INDICATIONS WITH FULL AND UNRESTR MOVEMENT IN BOTH DIRECTIONS. HOWEVER; FORWARD ELEVATOR MOVEMENT REQUIRED MORE FORCE THAN NORMAL AND A SLIGHT DELAY TO PRODUCE THE 'ELEVATOR PWR ON' ANNUNCIATOR LIGHT. AFT ELEVATOR MOVEMENT APPEARED NORMAL. TKOF RVR'S WERE 1000/1000/1000 FT. THE PERFORMANCE DATA/GROSS FOR RWY 19R WT PRODUCED A ROTATION SPD; VR OF 130 KTS. DURING THE TKOF ROLL AT ROTATIONAL SPD THE ELEVATOR FEEL WAS VERY HVY (IE; DEAD) AND NON RESPONSIVE TO NORMAL INPUTS. PROPER TKOF PITCH ATTITUDE WAS DIFFICULT TO OBTAIN BUT WAS ACCOMPLISHED AT A MUCH SLOWER THAN NORMAL RATE TO 10-13 FT ANU. ACCELERATION PAST VR WAS SO RAPID; ABORTING THE TKOF WAS NOT AN OPTION. MY PRIMARY CONCERN; BESIDES RWY LENGTH; WAS WITH ALL THIS ADDITIONAL ELEVATOR BACK FORCE; THAT THE ACFT WOULD SUDDENLY REACT AND OVER-ROTATE TO AN EXCESSIVE PITCH ATTITUDE. NOT KNOWING MY EXACT LIFTOFF POINT; THE ACFT BECAME AIRBORNE AROUND 180+ KTS. LUCKILY; I KNEW WE HAD A 10000+ FT RWY WITH NO OBSTACLES. THE ACFT NEVER FELT OUT OF TRIM(IE; NOSE HVY/NOSE LIGHT). DURING CRUISE TO ANC; AUTOPLT PITCH CTL WAS FAIR; BUT AT THE TIME APPEARED ACCEPTABLE. DURING OUR AUTOPLT OFF VISUAL APCH TO ANC RWY 6R; ELEVATOR FEEL AND RESPONSE APPEARED NORMAL BECAUSE OF MINIMAL USE AND USING STABILIZER TRIM FOR PRIMARY PITCH CTL. BUT ONCE WE STARTED TO SLOW AND CONFIGURE FOR LNDG; THE ELEVATOR BECAME STIFF AND NON RESPONSIVE TO NORMAL CTL FORCE INPUTS. A NORMAL VFR LNDG WAS ACCOMPLISHED USING ADDITIONAL SPD AND STABILIZER TRIM FOR ADDITIONAL PITCH CTL. MAINT INSPECTIONS IN ANC REVEALED NOTHING MECHANICALLY WRONG WITH THE ELEVATOR SYS. SOMETHING IN THE ELEVATOR CTL SYS HAD TO BE TOO COLD TO FUNCTION PROPERLY YET APPEAR TO CHK NORMAL. NOTE: WITHIN THE NEXT 18 HRS THIS EXACT EVENT RECURRED. AUTOPLT DISCONNECT ON AUTOLAND APCH/LNDG; INEFFECTIVE ELEVATOR TKOF AND LNDG. THIS ALL OCCURRED IN THE SAME ENVIRONMENTAL CONDITIONS; -40 DEGS C; SAME ARPT; FAI; SAME ACFT TYPE; MD80; BUT A DIFFERENT TAIL NUMBER. AT THE TIME OF THIS RPT MAINT INSPECTIONS ON BOTH ACFT REVEALED NOTHING MECHANICALLY WRONG. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ACFT WAS AN MD83 PWRED WITH P&W JT8D-219 ENGS. THE RPTR SAID ON LNDG AT FAI THE AUTOLAND APPEARED NORMAL UNTIL THE AUTOPLT DISCONNECTED DURING FLARE MODE AND PITCHED THE NOSE AGGRESSIVELY DOWN. THE RPTR SAID THE CTL CHK WAS NORMAL AND AFTER 33 MINS THE ACFT WAS READY FOR DEP TO ANC. THE RPTR STATED THE CTLS WERE AGAIN CHKED AND WERE FREE AND UNRESTR. THE RPTR STATED THAT DURING TKOF ROLL THE ELEVATOR FORCE WAS HVY AND WOULD NOT ROTATE AT THE CALCULATED VR OF 130 KTS BUT WAS MADE AT 180 KTS WITH 10-13 DEGS NOSE UP. THE RPTR SAID THE ELEVATORS WERE STIFF AND NON RESPONSIVE WHEN SLOWING DOWN ON APCH TO ANC. THE RPTR STATED THE DEP FROM FAI WAS AT -41 DEGS C. THE RPTR SAID THE NEXT DAY WHEN AT MAINT CTL CTR AT ZZZ RPTING ON THIS INCIDENT ANOTHER INCIDENT WAS BEING RPTED OF LIMITED PITCH CTL OUT OF FAI ON A COMPANY MD80. THE RPTR SAID THE ACFT HAD A DIFFERENT TAIL NUMBER AND THE RPT WAS ALMOST IDENTICAL WITH AUTOPLT DISCONNECTS AND HVY ELEVATOR FORCES IN THE SAME ENVIRONMENTAL CONDITIONS. THE RPTR SAID FORTUNATELY THIS SECOND ACFT WAS EQUIPPED WITH A DIGITAL FLT DATA RECORDER AND RECORDED A STICKING OR BYPASSING VALVE. THE RPTR DID NOT IDENT THE VALVE FUNCTION.