Narrative:

Somewhere during the middle of the first 1/3 of the flight, I noticed oil 2-3 inches wide slowly creeping out oil door top of cowling. I came to a conclusion the oil dipstick must have popped up. There was no change in oil pressure, oil temperature, or in cht over the next several mins and in fact, for the rest of the 1 hour 30 min flight. The oil coming out did not seem excessive enough to warrant a stop at the time. Hindsight being 20/20 and siding with caution, it would have been more safe to land. I landed and checked the dipstick. It was not secure -- resting on top of tube. A fair amount of oil appeared on top cowling and left side of aircraft. Windshield was fine. I left to help the architects I was flying for. Returned to find an FAA maintenance tag on the airplane. I talked to FAA inspector. He said to check breather and to check with a flashlight when flying for more oil. I asked him if I would be in violation if I flew it back. He said 'no this is not a violation.' I told him I feel safe in flying it back after my preflight. I put in 1 quart of oil after the linemen put in a quart -- 9 1/2 quarts in all, 1/2 quart over usual level. The oil dipstick is secure and breather tube didn't appear to have been clogged. The owner/operator helped me with the preflight that morning. I saw him check the oil and secure the cap but I guess he didn't secure it good enough, consequently the leak. There was no oil leaking on return trip. Postflt inspection proved oil to be at 9 1/2 quarts. I spoke with an FAA inspector. He told me maintenance men were waiting after hours to look at the airplane. This was not brought to my attention. Again I probably should have sided with extra caution and asked for a mechanic to take a look. Owner/operator replaced the o-ring on the dipstick the next day.

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Original NASA ASRS Text

Title: PLT OF AN SMA SEL FOUND OIL LEAKING FROM THE ENG COWLING INFLT AND FOUND THE DIPSTICK LOOSE AFTER LNDG.

Narrative: SOMEWHERE DURING THE MIDDLE OF THE FIRST 1/3 OF THE FLT, I NOTICED OIL 2-3 INCHES WIDE SLOWLY CREEPING OUT OIL DOOR TOP OF COWLING. I CAME TO A CONCLUSION THE OIL DIPSTICK MUST HAVE POPPED UP. THERE WAS NO CHANGE IN OIL PRESSURE, OIL TEMP, OR IN CHT OVER THE NEXT SEVERAL MINS AND IN FACT, FOR THE REST OF THE 1 HR 30 MIN FLT. THE OIL COMING OUT DID NOT SEEM EXCESSIVE ENOUGH TO WARRANT A STOP AT THE TIME. HINDSIGHT BEING 20/20 AND SIDING WITH CAUTION, IT WOULD HAVE BEEN MORE SAFE TO LAND. I LANDED AND CHKED THE DIPSTICK. IT WAS NOT SECURE -- RESTING ON TOP OF TUBE. A FAIR AMOUNT OF OIL APPEARED ON TOP COWLING AND L SIDE OF ACFT. WINDSHIELD WAS FINE. I LEFT TO HELP THE ARCHITECTS I WAS FLYING FOR. RETURNED TO FIND AN FAA MAINT TAG ON THE AIRPLANE. I TALKED TO FAA INSPECTOR. HE SAID TO CHK BREATHER AND TO CHK WITH A FLASHLIGHT WHEN FLYING FOR MORE OIL. I ASKED HIM IF I WOULD BE IN VIOLATION IF I FLEW IT BACK. HE SAID 'NO THIS IS NOT A VIOLATION.' I TOLD HIM I FEEL SAFE IN FLYING IT BACK AFTER MY PREFLT. I PUT IN 1 QUART OF OIL AFTER THE LINEMEN PUT IN A QUART -- 9 1/2 QUARTS IN ALL, 1/2 QUART OVER USUAL LEVEL. THE OIL DIPSTICK IS SECURE AND BREATHER TUBE DIDN'T APPEAR TO HAVE BEEN CLOGGED. THE OWNER/OPERATOR HELPED ME WITH THE PREFLT THAT MORNING. I SAW HIM CHK THE OIL AND SECURE THE CAP BUT I GUESS HE DIDN'T SECURE IT GOOD ENOUGH, CONSEQUENTLY THE LEAK. THERE WAS NO OIL LEAKING ON RETURN TRIP. POSTFLT INSPECTION PROVED OIL TO BE AT 9 1/2 QUARTS. I SPOKE WITH AN FAA INSPECTOR. HE TOLD ME MAINT MEN WERE WAITING AFTER HRS TO LOOK AT THE AIRPLANE. THIS WAS NOT BROUGHT TO MY ATTN. AGAIN I PROBABLY SHOULD HAVE SIDED WITH EXTRA CAUTION AND ASKED FOR A MECH TO TAKE A LOOK. OWNER/OPERATOR REPLACED THE O-RING ON THE DIPSTICK THE NEXT DAY.

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.