Narrative:

The WX at the time of departure was maximum visibility VFR. We received the takeoff clearance. Radar vectors were soon issued, during the climb to 10000 ft on runway heading. Passing through approximately 5000 ft, while flying radar vector headings, fuel was observed siphoning from the left wing fuel tank vent valve. I then asked the crew chief to attempt to look out of the canopy and verify the problem. This required that I drop the pilot's seat to the lowest position, so that the crew chief could look over my head. This restr the view outside of the aircraft, however it did not restrict view of the altimeter, the ADI, or the HSI. I leveled the aircraft at 10000 ft, with the airspeed at approximately 300 KTS. The crew chief continued his attempts to verify the fuel problem. I discussed the problem with the crew chief, while looking out the canopy at the rate of fuel venting. At this time, ATC issued a new vector for 'noise abatement'. I then turned to the heading assigned while continuing to discuss options on our fuel problem, as we both looked out at the left wing fuel vent. I inadvertently climbed to approximately 11000 ft. Scanning the instruments, I held the aircraft at 11000 ft, while switching fuel tanks and pumps in an attempt to slow the fuel siphoning. ATC requested verification of present altitude. I read back the altitude, while pushing the aircraft over, and we descended to 10000 ft. We again began working on the fuel siphoning problem, and I repeated the inadvertent climb to 11000 ft. I asked the navigator/ro to request a higher altitude. We were switched to another controller, and cleared direct to bebop maintain FL230. The new controller began interrogating me as to the previous clearance, as well as speed and altitude restrictions. The crew chief and I solved the fuel venting problem by transferring fuel. This was approximately 1 hour out. During the entire course of the flight, I had experienced great difficulty holding speed and altitude, for an undetermined reason. The aircraft seemed to 'feel' normal, and system were functioning normally. Aircraft center of gravity was not in question. Prior to departure, a new ADI and HSI had been installed in the aircraft. It was discovered that the vertical gyroscope which runs the ADI had been installed 180 degrees out of phase with the indicator, therefore giving erroneous readings in pitch and roll. The problem was corrected on the ground in honolulu, and the second leg of the trip was completed without incident.

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Original NASA ASRS Text

Title: GA MDT ALTDEV EXCURSION FROM CLRNC ALT ON STEP CLB OUT FROM SFO TOWARD HNL.

Narrative: THE WX AT THE TIME OF DEP WAS MAX VISIBILITY VFR. WE RECEIVED THE TKOF CLRNC. RADAR VECTORS WERE SOON ISSUED, DURING THE CLB TO 10000 FT ON RWY HDG. PASSING THROUGH APPROX 5000 FT, WHILE FLYING RADAR VECTOR HDGS, FUEL WAS OBSERVED SIPHONING FROM THE L WING FUEL TANK VENT VALVE. I THEN ASKED THE CREW CHIEF TO ATTEMPT TO LOOK OUT OF THE CANOPY AND VERIFY THE PROBLEM. THIS REQUIRED THAT I DROP THE PLT'S SEAT TO THE LOWEST POS, SO THAT THE CREW CHIEF COULD LOOK OVER MY HEAD. THIS RESTR THE VIEW OUTSIDE OF THE ACFT, HOWEVER IT DID NOT RESTRICT VIEW OF THE ALTIMETER, THE ADI, OR THE HSI. I LEVELED THE ACFT AT 10000 FT, WITH THE AIRSPD AT APPROX 300 KTS. THE CREW CHIEF CONTINUED HIS ATTEMPTS TO VERIFY THE FUEL PROBLEM. I DISCUSSED THE PROBLEM WITH THE CREW CHIEF, WHILE LOOKING OUT THE CANOPY AT THE RATE OF FUEL VENTING. AT THIS TIME, ATC ISSUED A NEW VECTOR FOR 'NOISE ABATEMENT'. I THEN TURNED TO THE HDG ASSIGNED WHILE CONTINUING TO DISCUSS OPTIONS ON OUR FUEL PROBLEM, AS WE BOTH LOOKED OUT AT THE L WING FUEL VENT. I INADVERTENTLY CLBED TO APPROX 11000 FT. SCANNING THE INSTS, I HELD THE ACFT AT 11000 FT, WHILE SWITCHING FUEL TANKS AND PUMPS IN AN ATTEMPT TO SLOW THE FUEL SIPHONING. ATC REQUESTED VERIFICATION OF PRESENT ALT. I READ BACK THE ALT, WHILE PUSHING THE ACFT OVER, AND WE DSNDED TO 10000 FT. WE AGAIN BEGAN WORKING ON THE FUEL SIPHONING PROBLEM, AND I REPEATED THE INADVERTENT CLB TO 11000 FT. I ASKED THE NAVIGATOR/RO TO REQUEST A HIGHER ALT. WE WERE SWITCHED TO ANOTHER CTLR, AND CLRED DIRECT TO BEBOP MAINTAIN FL230. THE NEW CTLR BEGAN INTERROGATING ME AS TO THE PREVIOUS CLRNC, AS WELL AS SPD AND ALT RESTRICTIONS. THE CREW CHIEF AND I SOLVED THE FUEL VENTING PROBLEM BY TRANSFERRING FUEL. THIS WAS APPROX 1 HR OUT. DURING THE ENTIRE COURSE OF THE FLT, I HAD EXPERIENCED GREAT DIFFICULTY HOLDING SPD AND ALT, FOR AN UNDETERMINED REASON. THE ACFT SEEMED TO 'FEEL' NORMAL, AND SYS WERE FUNCTIONING NORMALLY. ACFT CENTER OF GRAVITY WAS NOT IN QUESTION. PRIOR TO DEP, A NEW ADI AND HSI HAD BEEN INSTALLED IN THE ACFT. IT WAS DISCOVERED THAT THE VERT GYROSCOPE WHICH RUNS THE ADI HAD BEEN INSTALLED 180 DEGS OUT OF PHASE WITH THE INDICATOR, THEREFORE GIVING ERRONEOUS READINGS IN PITCH AND ROLL. THE PROBLEM WAS CORRECTED ON THE GND IN HONOLULU, AND THE SECOND LEG OF THE TRIP WAS COMPLETED WITHOUT INCIDENT.

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.