Narrative:

On IFR flight from wbw to bos en route level at 11000' MSL, attempted to cycle deicing boots, and at that time discovered complete loss of vacuum system. Upon discovering this, informed bos center of problem that I had no vacuum system or flight instruments on both pilot's and copilot's panel. Told bos center I wanted to remain on top at 11000' and return to avp. Was told by bos center that I could not remain at present altitude to return to avp because of conflicting traffic. Bos told me to descend to 10000' and make a 180 degree turn, which put me in IMC, handed me back T ny center who in turn handed me over to avp. Wilkes-barre approach offered to activate ILS 22 for my approach and landing, this was going to be a no gyro approach. At the time, there was a high right crosswind for the ASR. Wilkes-barre told me to descend and maintain 4000' MSL and turn left. I was told to stop turn, which I did. Wilkes-barre told me I was still in left turn, which I now believe was caused by high crosswind. Wilkes-barre kept insisting that I was still in left turn, which I tried to correct even though the needle and ball said I was not in turn. At that time I started to have doubts that the turn coordinator was working, kept turning right to stop turn that wilkes-barre said I was in, and ended up in an inverted confign, pulled throttles to idle and attempted to right plane and stop descent. Came into VFR conditions at approximately 2500', nose straight down and at high airspeed. Righted airplane and regained complete control. Proceeded VFR to avp and landed. Had mechanic check aircraft and he found both vacuum pump shafts were sheared. Have ordered new pumps and electric flight instruments for copilot's panel. I should have insisted on staying on top at 11000 or 12000' and going west till I could find broken or clear conditions that I could have landed VFR. Should have also not allowed controller to make me believe that I was in left turn when instrument said I was straight. Due to all circumstances, I allowed the controller to fly airplane with his radar and commands and did not believe what my instruments were telling me. I now believe that all twins should have one pilot's side air instrument and other side electric. With this set up, you must have a loss of both pumps and both electric system in order to have no flight instruments. Callback conversation with reporter revealed the following: the turn and bank was electrically pwred. Pilot broke out of clouds in a valley with hills to 2500' on both sides. ARTCC timed his descent from 6800' to 2600' as 6 seconds.

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Original NASA ASRS Text

Title: PLT OF CPR SMT LOST CTL OF ACFT IN IMC AND CAME OUT OF CLOUD COVER HEADED STRAIGHT DOWN AT 2500'. BOTH ACFT VACUUM SYSTEMS WERE INOPERATIVE LEAVING ONLY THE ELECTRIC TURN AND BACK FOR ACFT GUIDANCE.

Narrative: ON IFR FLT FROM WBW TO BOS ENRTE LEVEL AT 11000' MSL, ATTEMPTED TO CYCLE DEICING BOOTS, AND AT THAT TIME DISCOVERED COMPLETE LOSS OF VACUUM SYS. UPON DISCOVERING THIS, INFORMED BOS CENTER OF PROB THAT I HAD NO VACUUM SYS OR FLT INSTRUMENTS ON BOTH PLT'S AND COPLT'S PANEL. TOLD BOS CENTER I WANTED TO REMAIN ON TOP AT 11000' AND RETURN TO AVP. WAS TOLD BY BOS CENTER THAT I COULD NOT REMAIN AT PRESENT ALT TO RETURN TO AVP BECAUSE OF CONFLICTING TFC. BOS TOLD ME TO DSND TO 10000' AND MAKE A 180 DEG TURN, WHICH PUT ME IN IMC, HANDED ME BACK T NY CENTER WHO IN TURN HANDED ME OVER TO AVP. WILKES-BARRE APCH OFFERED TO ACTIVATE ILS 22 FOR MY APCH AND LNDG, THIS WAS GOING TO BE A NO GYRO APCH. AT THE TIME, THERE WAS A HIGH RIGHT XWIND FOR THE ASR. WILKES-BARRE TOLD ME TO DSND AND MAINTAIN 4000' MSL AND TURN LEFT. I WAS TOLD TO STOP TURN, WHICH I DID. WILKES-BARRE TOLD ME I WAS STILL IN LEFT TURN, WHICH I NOW BELIEVE WAS CAUSED BY HIGH XWIND. WILKES-BARRE KEPT INSISTING THAT I WAS STILL IN LEFT TURN, WHICH I TRIED TO CORRECT EVEN THOUGH THE NEEDLE AND BALL SAID I WAS NOT IN TURN. AT THAT TIME I STARTED TO HAVE DOUBTS THAT THE TURN COORDINATOR WAS WORKING, KEPT TURNING RIGHT TO STOP TURN THAT WILKES-BARRE SAID I WAS IN, AND ENDED UP IN AN INVERTED CONFIGN, PULLED THROTTLES TO IDLE AND ATTEMPTED TO RIGHT PLANE AND STOP DSCNT. CAME INTO VFR CONDITIONS AT APPROX 2500', NOSE STRAIGHT DOWN AND AT HIGH AIRSPD. RIGHTED AIRPLANE AND REGAINED COMPLETE CTL. PROCEEDED VFR TO AVP AND LANDED. HAD MECH CHK ACFT AND HE FOUND BOTH VACUUM PUMP SHAFTS WERE SHEARED. HAVE ORDERED NEW PUMPS AND ELECTRIC FLT INSTRUMENTS FOR COPLT'S PANEL. I SHOULD HAVE INSISTED ON STAYING ON TOP AT 11000 OR 12000' AND GOING W TILL I COULD FIND BROKEN OR CLR CONDITIONS THAT I COULD HAVE LANDED VFR. SHOULD HAVE ALSO NOT ALLOWED CTLR TO MAKE ME BELIEVE THAT I WAS IN LEFT TURN WHEN INSTRUMENT SAID I WAS STRAIGHT. DUE TO ALL CIRCUMSTANCES, I ALLOWED THE CTLR TO FLY AIRPLANE WITH HIS RADAR AND COMMANDS AND DID NOT BELIEVE WHAT MY INSTRUMENTS WERE TELLING ME. I NOW BELIEVE THAT ALL TWINS SHOULD HAVE ONE PLT'S SIDE AIR INSTRUMENT AND OTHER SIDE ELECTRIC. WITH THIS SET UP, YOU MUST HAVE A LOSS OF BOTH PUMPS AND BOTH ELECTRIC SYS IN ORDER TO HAVE NO FLT INSTRUMENTS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: THE TURN AND BANK WAS ELECTRICALLY PWRED. PLT BROKE OUT OF CLOUDS IN A VALLEY WITH HILLS TO 2500' ON BOTH SIDES. ARTCC TIMED HIS DSCNT FROM 6800' TO 2600' AS 6 SECS.

Data retrieved from NASA's ASRS site as of August 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.