Orlando, FL, USA
N777YM
Cirrus SR20
The pilot said that he was on the downwind leg for runway 07 when he observed the engine oil pressure caution light illuminate. Shortly thereafter, the engine lost power. He declared an emergency and landed on runway 13, touching down two-thirds down the runway. The airplane overran the end of the runway and struck a ditch. Eight hours before the accident flight, the owner/operator attempted to determine why there was a low oil quantity and oil was being vented out of the crankcase breather. An airframe and powerplant (A&P) mechanic examined the engine and could find no oil leaks. He also performed a cylinder compression check as outlined in Teledyne Continental Motors' (TCM) Service Bulletins M89-9, "Excessive Crankcase Pressures." No discrepancies were noted. The engine, a Teledyne Continental IO-360-ES (serial number 1393), was disassembled and examined. According to TCM's report, "The connecting rod assemblies exhibited thermal discoloration. The connecting rod bearings exhibited lubrication distress and thermal smearing of the surface babbit, exposing the copper layer. The number four piston head exhibited preignition/detonation damage. The thermal damage had penetrated through the interior of the piston. Portions of the piston rings were missing from thermal damage. The piston pin was intact. The pin plug was damaged from extreme thermal exposure." The magnetos were functionally checked and tested satisfactorily. The 12 spark plugs were also tested. Core nose cracks on five of the 12 spark plugs were attributed to detonation "but did not cause any side effects detrimental to normal engine operation." TCM's Service Bulletin M89-9, entitled "Excessive Crankcase Pressures," requires only a "differential pressure test of the cylinders" to check for cylinder preignition/detonation and excessive blow-by, and does not contain the verbiage contained in TCM's SB03-3, "Differential Pressure Test and Borescope Inspection Procedures for Cylinders."
On March 18, 2006, approximately 1245 eastern standard time, a Cirrus SR20, N777YM, registered to Boykie Leasing Trading LLC and piloted by a private pilot, was substantially damaged when it overran the runway and struck a ditch at the Orlando Executive Airport, Orlando, Florida. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under the provisions of Title 14 CFR Part 91 without a flight plan. The pilot, the sole occupant on board, was not injured. The cross-country flight originated from Pompano Beach Airpark, Pompano Beach, Florida approximately 1115. The pilot said that when he was on the downwind leg for runway 07, he observed the engine oil pressure caution light illuminate. Shortly thereafter, the engine lost power. He declared an emergency and landed on runway 13, touching down two-thirds down the runway. The airplane overran the end of the runway and struck a ditch. Eight flight hours before the accident flight, the owner/operator attempted to determine why there was a low oil quantity and oil was being vented out of the crankcase breather. An airframe and powerplant (A&P) mechanic examined the engine and could find no oil leaks. He also performed a cylinder compression check as outlined in Teledyne Continental Motors' (TCM) Service Bulletins M89-9, "Excessive Crankcase Pressures." No discrepancies were noted. NTSB's investigator-in-charge (IIC) reviewed the SB and noted a "differential pressure test of the cylinders" was all that was required to check for cylinder preignition/detonation and excessive blow-by. There was "no mention for borescoping the cylinders." The investigator suggested Service Bulletins M89-9 be amended to include the verbiage found in SB03-3 . The engine, a Teledyne Continental IO-360-ES (serial number 1393), was disassembled and examined at the company's factory in Mobile, Alabama, on May 16, 2006. According to TCM's report, "The connecting rod assemblies exhibited thermal discoloration. The connecting rod bearings exhibited lubrication distress and thermal smearing of the surface babbit, exposing the copper layer. The number four piston head exhibited preignition/detonation damage. The thermal damage had penetrated through the interior of the piston. Portions of the piston rings were missing from thermal damage. The piston pin was intact. The pin plug was damaged from extreme thermal exposure." On August 2, 2006, the Unison 6314 magnetos (serial numbers 03090575, left; 03090578, right) were functionally tested. According to Unison's report, both magnetos "continuously fired all 6 spark plugs gaps, and there appeared to be no degradation of the operation" of the magnetos. The 12 Champion RHM38E spark plugs installed in the engine were also tested. According to Champion's report, all but one of the spark plugs passed 180 PSIG pressurized spark testing. The one failure noted had a 'weak' spark. Resistance values were unusually high. Five of the returned spark plugs had core nose cracks that was attributed to detonation "but did not cause any side effects detrimental to normal engine operation." The report concluded, "No spark plug condition or defects were found that could have contributed to engine loss of oil pressure and subsequently total engine power loss."
Catastrophic engine failure due to a low oil level brought about by excessive blow-by and cylinder detonation. Contributing factors in this accident were the inadequate instructions contained in Service Bulletin M89-9 and the ditch.
Source: NTSB Aviation Accident Database
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