PLT OF A BEECH BE36 DIVERTED TO LAND AFTER THE ENG LOST PWR SOON AFTER TKOF DUE TO LOW OIL PRESSURE. THE CAUSE WAS LATER FOUND TO BE A DISCONNECTED OIL LINE NOT CONNECTED AFTER A RECENT ENG PRIMARY AIR PUMP REPLACEMENT.

Narrative

I DEPARTED MWC RWY 22 VFR ALONE (WIND 200 DEGS AT 8 KTS; 20000 FT BROKEN; VISIBILITY 7 MI) IN A 1982 TURBONORMALIZED BEECHCRAFT A36 WITH DEICING BOOTS; HOT PROP AND TIP TANKS. THE STARTING TACH TIME WAS 2708.14 HRS. I TURNED TO A HDG OF 190 DEGS AND LEVELED OFF AT 1800 FT MSL (1000 FT AGL); BELOW MKE CLASS C ENRTE TO ENW SOME 33 MI AND 173 DEGS FROM MWC. ALL INDICATIONS ON PREFLT; RUNUP AND CLBOUT APPEARED NORMAL. SEVERAL MINS LATER; I FELT THE ENG SURGE SLIGHTLY AND ONLY FOR AN INSTANT. EVERYTHING APPEARED NORMAL AS I RAPIDLY SCANNED THE GAUGES. WITHIN SECONDS; I NOTICED THE OIL PRESSURE BOUNCING BTWN 0 AND 1/2 WAY BELOW THE BOTTOM OF THE GREEN ARC. PWR; RPM; ENG OIL TEMP/CHT; AND 6 GAUGE EGT/CHT/TIT INDICATIONS ALL APPEARED NORMAL. I IMMEDIATELY WENT TO FULL RICH MIXTURE; TURNED 180 DEGS AND REQUESTED A CLB FROM MKE APCH CTL; NOTIFYING THEM OF THE LACK OF OIL PRESSURE AND INTENTION TO RETURN TO MWC GIVEN THAT ALL OTHER INDICATIONS WERE NORMAL. LESS THAN 1 MIN LATER; THE ENG BEGAN TO VIBRATE MODERATELY; AUDIBLY VOICE ITS DISPLEASURE AND BEGIN LOSING PWR. SIMULTANEOUSLY; APCH CTL OFFERED THAT MKE WAS SEVERAL MI TO THE ENE. I ACCEPTED THE TIMELY OFFER WITHOUT HESITATION AND BANKED DIRECTLY TOWARD RWY 7R; CLRLY IN VIEW SOME 6-7 MI TO THE E. I ESTABLISHED BEST GLIDE SPD; MAINTAINED ALT AND REDUCED PWR TO 15 INCHES HOPING (PRAYING) THE ENG WOULDN'T SEIZE AND SEARCHED DESPERATELY FOR A SUITABLE LNDG SITE SHORT OF RWY 7R. TWR CLRED ME TO LAND; KINDLY REMINDED ME TO CHK GEAR DOWN; AND ACTIVATED THE EMER GND EQUIP. UPON REACHING SUITABLE GLIDING DISTANCE; I CUT THE PWR TO IDLE; PULLED THE PROP TO FULL LOW; THEN DROPPED THE GEAR AND EVENTUALLY FULL FLAPS. THE LNDG AND ROLLOUT WERE UNEVENTFUL. I CLRED RWY 7R AND IMMEDIATELY SHUT DOWN THE DYING POWERPLANT. UPON EXITING THE PLANE; I NOTICED THE BELLY WAS SOAKED IN OIL; APPARENTLY EXITING THE ENG COMPARTMENT FROM THE COWL FLAP OPENING. I WAS GIVEN A RIDE TO AN OFFICE; FROM WHICH I CALLED THE CTL TWR; IDENTED MYSELF AS THE PLT OF SMA; AND ASKED IF THEY REQUIRED ANY INFO FROM ME. THEY DID NOT. SUBSEQUENT CLOSER INSPECTION BY SEVERAL MECHS AND THE FAA HAS CONFIRMED THAT THE OIL RETURN LINE FITTING FROM THE TURBONORMALIZER PRESSURE CONTROLLER WAS DISCONNECTED AT THE L REAR OF THE ENG. AN INCIDENTAL CRACK IN THE CASE WAS ALSO FOUND AT THE TOP BASE OF THE #3 CYLINDER; I SUSPECT RESULTING FROM THE STRESS OF OPERATING FOR SEVERAL MINS WITH LITTLE IF ANY OIL. THE FITTING IN QUESTION IS IMMEDIATELY ADJACENT TO THE PRIMARY AIR PUMP THAT WAS REPLACED SEVERAL DAYS BEFORE THE ILL-FATED FLT. ACFT FLEW FLAWLESSLY NONSTOP FROM MWC-APF (6.48 TACH HRS) ON JAN/THU/99. THE PRIMARY AIR PUMP FAILED ON THE RETURN FLT JAN/SUN/99 WHICH WAS OTHERWISE UNEVENTFUL (ENDING TACH TIME 2708.05). THE PRIMARY AIR PUMP WAS REPLACED 4 DAYS LATER. THE TACHOMETER TIME AFTER AN OPERATIONAL CHK WAS 2708.14 HRS. FBO IS FAMILIAR WITH THE PLANE HAVING PERFORMED LAST ANNUAL IN MAR/98. THOUGH THE INVESTIGATION IS ONGOING; I STRONGLY SUSPECT THE OIL RETURN LINE FITTING WAS DISCONNECTED IN ORDER TO REMOVE AND REPLACE THE PRIMARY AIR PUMP AND SUBSEQUENTLY NOT RECONNECTED. THE ENG WAS RUN .09 HRS FOR AN OPERATIONAL CHK; THOUGH NO MENTION WAS MADE IN THE LOGBOOK OF A LEAK CHK. I DID NOT NOTICE ANY OIL DURING PREFLT. I UNDERSTAND; FROM SPEAKING WITH AN INDEPENDENT A&P; THAT ONLY A SMALL AMOUNT OF OIL MAY HAVE LEAKED DURING THE OPERATIONAL CHK IF THE RPM WAS NOT BROUGHT UP HIGH ENOUGH; EVEN WITH THE LINE COMPLETELY DISCONNECTED.