Narrative:

Pilot took off for a brief pleasure flight and limited aerobatics. Flew to practice area about 10 mi west of iow and climbed to 4500 ft AGL. After some wing-overs, pilot performed a sequence of 7 or 8 rolls. Upon turning back to the airport, the pilot noticed a decrease of power, low oil pressure and high oil temperature. Pilot attempted to nurse the plane back to the airport, but engine kept losing power and eventually seized about 2 mi west of iow. Pilot safely landed the plane in a soybean field with no injuries to the pilot or damage to plane (excluding the toasted engine). While the cause of the oil problem has not been definitely idented, pilot believes there was a problem with the inverted oil system causing the engine to lose a little bit of oil each time the plane went inverted. On earlier flts, the pilot had done some aggressive pushovers (reaching 0 G's) and each time there was a loss of approximately 1 quart of oil for the flight (approximately 5-10 pushovers). By the time the pilot turned toward the airport, there was likely very little oil left in the engine. Although the plane and engine had 180 hours on it, the airplane had only been inverted a couple of times for a short duration (during rolls by a previous pilot). Therefore, the inverted oil system may never have been fully tested. To have prevented this situation, there are several things the pilot could have done. The pilot should have done a single roll and then returned to have the system inspected. Also, the pilot should have paid closer attention to the oil gauges during the flight and especially monitored it after each roll. If the pilot had noticed the problem sooner, the airplane could have returned to the airport and not have damaged the engine. Ultimately, the pilot should have considered that he was expanding the envelope of the airplane's operations and treated the flight as a test flight rather than a pleasure flight. Additionally, the pilot probably should have landed as soon as the problem was idented rather than trying to make it back to the airport. There were plenty of level fields available. The pilot was concerned to make it back to the airport. There were plenty of level fields available. The pilot was concerned about the relative high landing speed of the plane and didn't realize the quickness the engine would deteriorate. The pilot felt that the engine would hold together long enough to reach the airport and weighed the cost of damaging the engine as better than the risk of an off airport landing. Unfortunately, he got stuck with both.

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Original NASA ASRS Text

Title: THE PLT OF A STEEN SKYBOLT IS FORCED INTO AN EMER OFF ARPT LNDG WHEN THE ENG RUNS OUT OF OIL 3 MI W OF IOW, IA.

Narrative: PLT TOOK OFF FOR A BRIEF PLEASURE FLT AND LIMITED AEROBATICS. FLEW TO PRACTICE AREA ABOUT 10 MI W OF IOW AND CLBED TO 4500 FT AGL. AFTER SOME WING-OVERS, PLT PERFORMED A SEQUENCE OF 7 OR 8 ROLLS. UPON TURNING BACK TO THE ARPT, THE PLT NOTICED A DECREASE OF PWR, LOW OIL PRESSURE AND HIGH OIL TEMP. PLT ATTEMPTED TO NURSE THE PLANE BACK TO THE ARPT, BUT ENG KEPT LOSING PWR AND EVENTUALLY SEIZED ABOUT 2 MI W OF IOW. PLT SAFELY LANDED THE PLANE IN A SOYBEAN FIELD WITH NO INJURIES TO THE PLT OR DAMAGE TO PLANE (EXCLUDING THE TOASTED ENG). WHILE THE CAUSE OF THE OIL PROB HAS NOT BEEN DEFINITELY IDENTED, PLT BELIEVES THERE WAS A PROB WITH THE INVERTED OIL SYS CAUSING THE ENG TO LOSE A LITTLE BIT OF OIL EACH TIME THE PLANE WENT INVERTED. ON EARLIER FLTS, THE PLT HAD DONE SOME AGGRESSIVE PUSHOVERS (REACHING 0 G'S) AND EACH TIME THERE WAS A LOSS OF APPROX 1 QUART OF OIL FOR THE FLT (APPROX 5-10 PUSHOVERS). BY THE TIME THE PLT TURNED TOWARD THE ARPT, THERE WAS LIKELY VERY LITTLE OIL LEFT IN THE ENG. ALTHOUGH THE PLANE AND ENG HAD 180 HRS ON IT, THE AIRPLANE HAD ONLY BEEN INVERTED A COUPLE OF TIMES FOR A SHORT DURATION (DURING ROLLS BY A PREVIOUS PLT). THEREFORE, THE INVERTED OIL SYS MAY NEVER HAVE BEEN FULLY TESTED. TO HAVE PREVENTED THIS SIT, THERE ARE SEVERAL THINGS THE PLT COULD HAVE DONE. THE PLT SHOULD HAVE DONE A SINGLE ROLL AND THEN RETURNED TO HAVE THE SYS INSPECTED. ALSO, THE PLT SHOULD HAVE PAID CLOSER ATTN TO THE OIL GAUGES DURING THE FLT AND ESPECIALLY MONITORED IT AFTER EACH ROLL. IF THE PLT HAD NOTICED THE PROB SOONER, THE AIRPLANE COULD HAVE RETURNED TO THE ARPT AND NOT HAVE DAMAGED THE ENG. ULTIMATELY, THE PLT SHOULD HAVE CONSIDERED THAT HE WAS EXPANDING THE ENVELOPE OF THE AIRPLANE'S OPS AND TREATED THE FLT AS A TEST FLT RATHER THAN A PLEASURE FLT. ADDITIONALLY, THE PLT PROBABLY SHOULD HAVE LANDED AS SOON AS THE PROB WAS IDENTED RATHER THAN TRYING TO MAKE IT BACK TO THE ARPT. THERE WERE PLENTY OF LEVEL FIELDS AVAILABLE. THE PLT WAS CONCERNED TO MAKE IT BACK TO THE ARPT. THERE WERE PLENTY OF LEVEL FIELDS AVAILABLE. THE PLT WAS CONCERNED ABOUT THE RELATIVE HIGH LNDG SPD OF THE PLANE AND DIDN'T REALIZE THE QUICKNESS THE ENG WOULD DETERIORATE. THE PLT FELT THAT THE ENG WOULD HOLD TOGETHER LONG ENOUGH TO REACH THE ARPT AND WEIGHED THE COST OF DAMAGING THE ENG AS BETTER THAN THE RISK OF AN OFF ARPT LNDG. UNFORTUNATELY, HE GOT STUCK WITH BOTH.

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.