Narrative:

After takeoff and during climb out from the pocatello airport, I began to notice a problem. The pih VOR was only 3 mi away, yet it was taking an extraordinary amount of time to get there. I double-checked my slaved heading indicator/HSI. I determined that it was inoperative and rotating freely. I concluded I was 'chasing' the heading indicator, and therefore I was in a turn. To add to the problem, my artificial horizon was also failed. Another INS rated pilot sitting next to me selected alternate air for the gyros, with no luck. He then continually told me to watch my airspeed, which was 10-15 KTS below vy speed. I told him I was pushing forward on the yoke as hard as I could, but the yoke wasn't responding. After further inspection of the electrical trim system, it was determined that the trim wheel was unmovable. Approximately 4 mins had gone by after takeoff, and we hadn't yet reached the VOR. I asked ZLC for a position report, and his reply was, '3 mi out on the 055 degree right from pih VOR.' at this time we were climbing fiercely out of 10000' with a clearance to FL240. I then told the controller our situation. 'ZLC,... With a problem here. We have total gyro failure, negative trim with the airplane trimmed into a climb attitude, and we're IMC, over.' 'controller, say intentions and assistance needed from ATC.' 'we need vectors for V500 westbound and I'd like to level off at 14000'.' the controller then gave us no gyro vectors to V500. I then requested a block altitude 13000-15000' because it was taking 2 pilots to hold the aircraft in the level flight attitude, because of the inoperative trim. We decided to continue the flight to boise where it was VFR. As the flight progressed, center advised us they were handling us as an emergency, and asked if emergency equipment would be needed at boise. I replied, 'negative.' after about 30 mins, the trim was finally able to be controled manually with much force. 20 mins after that, the alternate air finally got my artificial horizon working. I noticed that my HSI was working intermittently. I cancelled my block altitude with center and received my clearance on to bfi west/O further incidence. An item that contributed to the situation was WX. Pih was reporting a temperature of -9 degrees F. Our aircraft had only sat there for 1-2 hours. We preheated the aircraft and used an external power source to get the aircraft to start. After a lengthy warmup and systems check, the aircraft was in perfect condition. It was only after takeoff that the systems began to fail. My conclusion is that the preheater induced some moisture which froze after takeoff. I assume that the gyros and the trim system were frozen. After enough time, the cabin heat must have helped to free the systems. My suggestion on how to prevent this occurrence is maybe there are days when it is just too cold to fly.

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Original NASA ASRS Text

Title: AFTER PREWARMING ACFT AND TAKING OFF PIH WITH TEMPERATURE -9 DEGREES F, PLT REALIZED HIS NAVIGATION INS AND ARTIFICIAL HORIZON WERE INOPERATIVE AND ACFT COULD NOT BE TRIMMED. DIFFICULTY WITH AIRSPEED CTL AND NAVIGATION ASSISTANCE WAS GIVEN BY ZLC. LATER AUX SOURCE OF AIR RIGHTED THE ARTIFICIAL HORIZON AND OTHER INS BECAME OPERATIVE AND FLT PROCEEDED TO BWI.

Narrative: AFTER TKOF AND DURING CLBOUT FROM THE POCATELLO ARPT, I BEGAN TO NOTICE A PROB. THE PIH VOR WAS ONLY 3 MI AWAY, YET IT WAS TAKING AN EXTRAORDINARY AMOUNT OF TIME TO GET THERE. I DOUBLE-CHKED MY SLAVED HDG INDICATOR/HSI. I DETERMINED THAT IT WAS INOP AND ROTATING FREELY. I CONCLUDED I WAS 'CHASING' THE HDG INDICATOR, AND THEREFORE I WAS IN A TURN. TO ADD TO THE PROB, MY ARTIFICIAL HORIZON WAS ALSO FAILED. ANOTHER INS RATED PLT SITTING NEXT TO ME SELECTED ALTERNATE AIR FOR THE GYROS, WITH NO LUCK. HE THEN CONTINUALLY TOLD ME TO WATCH MY AIRSPD, WHICH WAS 10-15 KTS BELOW VY SPD. I TOLD HIM I WAS PUSHING FORWARD ON THE YOKE AS HARD AS I COULD, BUT THE YOKE WASN'T RESPONDING. AFTER FURTHER INSPECTION OF THE ELECTRICAL TRIM SYS, IT WAS DETERMINED THAT THE TRIM WHEEL WAS UNMOVABLE. APPROX 4 MINS HAD GONE BY AFTER TKOF, AND WE HADN'T YET REACHED THE VOR. I ASKED ZLC FOR A POS RPT, AND HIS REPLY WAS, '3 MI OUT ON THE 055 DEG R FROM PIH VOR.' AT THIS TIME WE WERE CLBING FIERCELY OUT OF 10000' WITH A CLRNC TO FL240. I THEN TOLD THE CTLR OUR SITUATION. 'ZLC,... WITH A PROB HERE. WE HAVE TOTAL GYRO FAILURE, NEGATIVE TRIM WITH THE AIRPLANE TRIMMED INTO A CLB ATTITUDE, AND WE'RE IMC, OVER.' 'CTLR, SAY INTENTIONS AND ASSISTANCE NEEDED FROM ATC.' 'WE NEED VECTORS FOR V500 WBND AND I'D LIKE TO LEVEL OFF AT 14000'.' THE CTLR THEN GAVE US NO GYRO VECTORS TO V500. I THEN REQUESTED A BLOCK ALT 13000-15000' BECAUSE IT WAS TAKING 2 PLTS TO HOLD THE ACFT IN THE LEVEL FLT ATTITUDE, BECAUSE OF THE INOP TRIM. WE DECIDED TO CONTINUE THE FLT TO BOISE WHERE IT WAS VFR. AS THE FLT PROGRESSED, CENTER ADVISED US THEY WERE HANDLING US AS AN EMER, AND ASKED IF EMER EQUIP WOULD BE NEEDED AT BOISE. I REPLIED, 'NEGATIVE.' AFTER ABOUT 30 MINS, THE TRIM WAS FINALLY ABLE TO BE CTLED MANUALLY WITH MUCH FORCE. 20 MINS AFTER THAT, THE ALTERNATE AIR FINALLY GOT MY ARTIFICIAL HORIZON WORKING. I NOTICED THAT MY HSI WAS WORKING INTERMITTENTLY. I CANCELLED MY BLOCK ALT WITH CENTER AND RECEIVED MY CLRNC ON TO BFI W/O FURTHER INCIDENCE. AN ITEM THAT CONTRIBUTED TO THE SITUATION WAS WX. PIH WAS RPTING A TEMP OF -9 DEGS F. OUR ACFT HAD ONLY SAT THERE FOR 1-2 HRS. WE PREHEATED THE ACFT AND USED AN EXTERNAL PWR SOURCE TO GET THE ACFT TO START. AFTER A LENGTHY WARMUP AND SYSTEMS CHK, THE ACFT WAS IN PERFECT CONDITION. IT WAS ONLY AFTER TKOF THAT THE SYSTEMS BEGAN TO FAIL. MY CONCLUSION IS THAT THE PREHEATER INDUCED SOME MOISTURE WHICH FROZE AFTER TKOF. I ASSUME THAT THE GYROS AND THE TRIM SYS WERE FROZEN. AFTER ENOUGH TIME, THE CABIN HEAT MUST HAVE HELPED TO FREE THE SYSTEMS. MY SUGGESTION ON HOW TO PREVENT THIS OCCURRENCE IS MAYBE THERE ARE DAYS WHEN IT IS JUST TOO COLD TO FLY.

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.