Narrative:

While returning to MCAS el toro on an IFR flight plan, I abruptly experienced an extremely rough running engine. Center handed me to coast approach and vectored me to long beach for a high entry to the long beach ILS. I observed oil pressure as low as 2-3 psi and was quite sure the engine was about to freeze. Approach immediately descended me to lower altitudes in IFR conditions even though the overcast was burning off to the east. When I broke out, I was below 1500 ft and could not see the airport or runway. As the aircraft increased angle of attack, the engine caught and I commenced a gradual climbing turn toward the long beach airport. I immediately thereafter spotted the runway and was cleared to land. I taxied to a local FBO and shut down the plane. This small aircraft has an 11 quart oil capacity and required 9 quarts. It holds 50 gallons of fuel and required 48.8 gallons. On 9/thu/92, I flew a .8 hour check-out in the airplane with one of the aeronautical club cfis. He advised me that appropriate cruise power settings were 2400 RPM and manifold pressure as achievable based on altitude. Historical fuel consumption averaged about 11.5 to 12 gallons per hour based on my checking. He also advised me that the engine used considerable oil, as much as 1 quart per hour. On 9/sat/92, I confirmed full fuel and added a quart of oil (to 10 quarts) and flew 1.6 hours from el toro to paso robles. Tue morning, prior to starting my return to el toro, I confirmed fuel visually and per the gauges, which read approximately 15 gallons per side. After flying about 1.2 hours (the time of the incident) the right tank gauge read 15 gallons and the left gauge read about 4 gallons. I became aware of the apparent asymmetric fuel flow about 5 mins before the rough running. There were 2 major problems, ie, excessive oil consumption and excessive fuel consumption, and one minor problem faulty fuel gauge(south). More precise fuel planning with proper guidance from the instructor would be indicated. Current performance data for flight planning use would be preferable to the 1954 information provided in the manual. Center's vectoring and descending me and my accepting their instructions into known IFR conditions should be reconsidered.

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Original NASA ASRS Text

Title: AN SMA, FORMER MIL TRAINER, LOST ALMOST ALL OF IT'S OIL AND USED TOO MUCH FUEL WHILE THE RPTR WAS FLYING ON TOP OF AN OVCST.

Narrative: WHILE RETURNING TO MCAS EL TORO ON AN IFR FLT PLAN, I ABRUPTLY EXPERIENCED AN EXTREMELY ROUGH RUNNING ENG. CTR HANDED ME TO COAST APCH AND VECTORED ME TO LONG BEACH FOR A HIGH ENTRY TO THE LONG BEACH ILS. I OBSERVED OIL PRESSURE AS LOW AS 2-3 PSI AND WAS QUITE SURE THE ENG WAS ABOUT TO FREEZE. APCH IMMEDIATELY DSNDED ME TO LOWER ALTS IN IFR CONDITIONS EVEN THOUGH THE OVCST WAS BURNING OFF TO THE E. WHEN I BROKE OUT, I WAS BELOW 1500 FT AND COULD NOT SEE THE ARPT OR RWY. AS THE ACFT INCREASED ANGLE OF ATTACK, THE ENG CAUGHT AND I COMMENCED A GRADUAL CLBING TURN TOWARD THE LONG BEACH ARPT. I IMMEDIATELY THEREAFTER SPOTTED THE RWY AND WAS CLRED TO LAND. I TAXIED TO A LCL FBO AND SHUT DOWN THE PLANE. THIS SMA HAS AN 11 QUART OIL CAPACITY AND REQUIRED 9 QUARTS. IT HOLDS 50 GALLONS OF FUEL AND REQUIRED 48.8 GALLONS. ON 9/THU/92, I FLEW A .8 HR CHK-OUT IN THE AIRPLANE WITH ONE OF THE AERO CLUB CFIS. HE ADVISED ME THAT APPROPRIATE CRUISE PWR SETTINGS WERE 2400 RPM AND MANIFOLD PRESSURE AS ACHIEVABLE BASED ON ALT. HISTORICAL FUEL CONSUMPTION AVERAGED ABOUT 11.5 TO 12 GALLONS PER HR BASED ON MY CHKING. HE ALSO ADVISED ME THAT THE ENG USED CONSIDERABLE OIL, AS MUCH AS 1 QUART PER HR. ON 9/SAT/92, I CONFIRMED FULL FUEL AND ADDED A QUART OF OIL (TO 10 QUARTS) AND FLEW 1.6 HRS FROM EL TORO TO PASO ROBLES. TUE MORNING, PRIOR TO STARTING MY RETURN TO EL TORO, I CONFIRMED FUEL VISUALLY AND PER THE GAUGES, WHICH READ APPROX 15 GALLONS PER SIDE. AFTER FLYING ABOUT 1.2 HRS (THE TIME OF THE INCIDENT) THE R TANK GAUGE READ 15 GALLONS AND THE L GAUGE READ ABOUT 4 GALLONS. I BECAME AWARE OF THE APPARENT ASYMMETRIC FUEL FLOW ABOUT 5 MINS BEFORE THE ROUGH RUNNING. THERE WERE 2 MAJOR PROBLEMS, IE, EXCESSIVE OIL CONSUMPTION AND EXCESSIVE FUEL CONSUMPTION, AND ONE MINOR PROBLEM FAULTY FUEL GAUGE(S). MORE PRECISE FUEL PLANNING WITH PROPER GUIDANCE FROM THE INSTRUCTOR WOULD BE INDICATED. CURRENT PERFORMANCE DATA FOR FLT PLANNING USE WOULD BE PREFERABLE TO THE 1954 INFO PROVIDED IN THE MANUAL. CTR'S VECTORING AND DSNDING ME AND MY ACCEPTING THEIR INSTRUCTIONS INTO KNOWN IFR CONDITIONS SHOULD BE RECONSIDERED.

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.