A BE35 at 3500 ft noted drop in oil pressure. Advised ATC and advised to descend to 2000 ft. On desc...

Attributes
ACN	726815
Time
Date	200702
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	msl single value : 2000
Environment
Flight Conditions	IMC
Weather Elements	Ice
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : zzz.tracon
Operator	general aviation : personal
Make Model Name	Bonanza 35
Operating Under FAR Part	Part 91
Flight Phase	descent : approach
Route In Use	arrival : on vectors
Flight Plan	None
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : private
Experience	flight time last 90 days : 21 flight time total : 1377 flight time type : 801
ASRS Report	726815
Person 2
Affiliation	government : faa
Function	controller : approach
Events
Anomaly	aircraft equipment problem : critical altitude deviation : excursion from assigned altitude inflight encounter : weather maintenance problem : improper maintenance non adherence : far non adherence : published procedure other spatial deviation
Independent Detector	aircraft equipment other aircraft equipment : oil press ind. heading deviation other flight crewa
Resolutory Action	flight crew : diverted to another airport flight crew : overcame equipment problem
Consequence	other
Factors
Maintenance	performance deficiency : inspection performance deficiency : repair
Supplementary
Problem Areas	Aircraft Chart Or Publication Maintenance Human Performance Weather
Primary Problem	Maintenance Human Performance

Narrative:

In the morning I received an FSS briefing and also looked at NOAA WX on-line. The trip originated at ZZZ; us; with a stop at ZZZ1; us; on an IFR flight plan. On this leg I quickly picked up ice when briefly entering the clouds. After departing ZZZ1 I elected not to pick up my IFR flight plan and stay under the cloud ceiling of 3500 ft. Forecast ceilings in the ZZZ2 area were 1300-2500 ft. I could not pick up ZZZ2 ATIS or ZZZ2 AWOS until about 20 mi from ZZZ VOR. At this time I heard of ceilings of 500-600 ft. I climbed to 3500 ft and called ZZZ2 approach and requested the ILS. At this time I became aware of a drop in oil pressure. ZZZ approach gave me an initial heading of 170 degrees and descend to 2000 ft. On entering the clouds the directional gyro seem to first swing off heading and my autoplt would not hold the heading. I recycled my autoplt; but it would still not hold the heading. While trying to set my directional gyro to the compass I fell below 2000 ft. After the controller radioed that I had a possible directional gyro problem I started to rely on my compass and GPS to navigation. ATC instructed me to get lower till I broke out of the clouds. I then was instructed to proceed to ZZZ4 airport. The next morning I went back to ZZZ4 airport to possibly bring my plane to its home airport. Upon cranking the engine I had no oil pressure indicated and no drop when feathering the propeller. My aircraft remains at ZZZ4. I have already told my mechanic that I'll want another directional gyro. Callback conversation with reporter revealed the following information: the airplane had major engine work and was operated for 11 hours until the drop and loss of oil pressure incident. Had a technician check the engine over and it was discovered the oil pressure relief valve was jammed open by bits of brass safety wire. Cleaned everything and the engine operated normally. A new directional gyro corrected the instrumentation and autoplt problem.

Original NASA ASRS Text

Title: A BE35 AT 3500 FT NOTED DROP IN OIL PRESSURE. ADVISED ATC AND ADVISED TO DSND TO 2000 FT. ON DSCNT LOST DIRECTIONAL GYRO AND AUTOPLT. ADVISED TO DSND TO 600 FT AND BROKE OUT OF CLOUDS AND PROCEEDED TO ARPT.

Narrative: IN THE MORNING I RECEIVED AN FSS BRIEFING AND ALSO LOOKED AT NOAA WX ON-LINE. THE TRIP ORIGINATED AT ZZZ; US; WITH A STOP AT ZZZ1; US; ON AN IFR FLT PLAN. ON THIS LEG I QUICKLY PICKED UP ICE WHEN BRIEFLY ENTERING THE CLOUDS. AFTER DEPARTING ZZZ1 I ELECTED NOT TO PICK UP MY IFR FLT PLAN AND STAY UNDER THE CLOUD CEILING OF 3500 FT. FORECAST CEILINGS IN THE ZZZ2 AREA WERE 1300-2500 FT. I COULD NOT PICK UP ZZZ2 ATIS OR ZZZ2 AWOS UNTIL ABOUT 20 MI FROM ZZZ VOR. AT THIS TIME I HEARD OF CEILINGS OF 500-600 FT. I CLBED TO 3500 FT AND CALLED ZZZ2 APCH AND REQUESTED THE ILS. AT THIS TIME I BECAME AWARE OF A DROP IN OIL PRESSURE. ZZZ APCH GAVE ME AN INITIAL HDG OF 170 DEGS AND DSND TO 2000 FT. ON ENTERING THE CLOUDS THE DIRECTIONAL GYRO SEEM TO FIRST SWING OFF HDG AND MY AUTOPLT WOULD NOT HOLD THE HDG. I RECYCLED MY AUTOPLT; BUT IT WOULD STILL NOT HOLD THE HDG. WHILE TRYING TO SET MY DIRECTIONAL GYRO TO THE COMPASS I FELL BELOW 2000 FT. AFTER THE CTLR RADIOED THAT I HAD A POSSIBLE DIRECTIONAL GYRO PROB I STARTED TO RELY ON MY COMPASS AND GPS TO NAV. ATC INSTRUCTED ME TO GET LOWER TILL I BROKE OUT OF THE CLOUDS. I THEN WAS INSTRUCTED TO PROCEED TO ZZZ4 ARPT. THE NEXT MORNING I WENT BACK TO ZZZ4 ARPT TO POSSIBLY BRING MY PLANE TO ITS HOME ARPT. UPON CRANKING THE ENG I HAD NO OIL PRESSURE INDICATED AND NO DROP WHEN FEATHERING THE PROP. MY ACFT REMAINS AT ZZZ4. I HAVE ALREADY TOLD MY MECH THAT I'LL WANT ANOTHER DIRECTIONAL GYRO. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE AIRPLANE HAD MAJOR ENG WORK AND WAS OPERATED FOR 11 HRS UNTIL THE DROP AND LOSS OF OIL PRESSURE INCIDENT. HAD A TECHNICIAN CHK THE ENG OVER AND IT WAS DISCOVERED THE OIL PRESSURE RELIEF VALVE WAS JAMMED OPEN BY BITS OF BRASS SAFETY WIRE. CLEANED EVERYTHING AND THE ENG OPERATED NORMALLY. A NEW DIRECTIONAL GYRO CORRECTED THE INSTRUMENTATION AND AUTOPLT PROB.

Data retrieved from NASA's ASRS site as of January 2009 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.

A BE35 at 3500 ft noted drop in oil pressure. Advised ATC and advised to descend to 2000 ft. On descent lost directional gyro and autoplt. Advised to descend to 600 ft and broke out of clouds and proceeded to airport.