Overview
On October 3, 2017, about 1521 Pacific daylight time, a Cirrus Design Corp SR22 airplane (registration N418CP) was substantially damaged during an accident near Blythe, California. The flight instructor and the pilot receiving instruction sustained minor injuries. The flight was being conducted as a Title 14 Code of Federal Regulations Part 91 instructional flight.
Flight Details
According to the flight instructor, the purpose of the cross-country flight was to reposition the airplane for the new owner and provide advanced transition training. The instructor and pilot reviewed the airplane's logbooks and planned the flight before departure. The fuel tanks were filled, and no oil residue was observed on the airplane’s belly during the preflight inspection.
Sequence of Events
Flight data recorder data showed that after an uneventful takeoff at 1347:22, the airplane climbed and leveled off at a cruise altitude of about 11,500 ft mean sea level at 1359:38. At about 1505:00, the oil pressure began to decrease. Approximately 1.5 minutes later, oil pressure dropped below 30 psi. The instructor reported they decided to divert to Blythe Airport (BLH). While inbound, oil pressure continued to decrease to less than 5 psi. Shortly thereafter, the engine lost all power. Unable to reach the runway, the pilots activated the airplane's parachute system at about 2,000 ft above ground level. The parachute deployed successfully, and upon ground impact, it dragged the airplane about 20 ft. The pilots egressed, and the parachute dragged the airplane another 200 ft, during which the nose landing gear and left main landing gear collapsed.
Maintenance History
Maintenance records indicated that an annual inspection was completed earlier on the day of the accident flight. Actions were taken to comply with turbocharger manufacturer’s Safety Bulletin (SB) TAT SB11-04, which instructed owners to inspect and clean the turbocharger oil supply inlet screen regularly. The SB detailed procedures including removal of the oil line, valve assembly, and reinstallation with thread sealant and torquing to 85 inch-lbs. A postmaintenance ground run was conducted, and no oil leaks were noted.
Postaccident Examination
Examination revealed that the fuselage and engine firewall were substantially damaged. The b-nut fitting attaching the oil supply line to the turbocharger inlet check valve was found loose and could be rotated by hand. Fresh oil was present around the b-nut and on the engine’s right side near the turbocharger. The cowling bottom’s right side showed significantly more oil staining than the left. The b-nut and threads were undamaged. No other turbocharger anomalies were found.
The engine remained attached to its mounts with no external cylinder damage. All accessories were attached. A small hole was found on the top of the engine crankcase, consistent with an internal engine failure. Ignition, exhaust, and induction systems showed no anomalies. Spark plugs exhibited normal wear.
Boroscopic examination revealed that Nos. 3 and 4 connecting rods had separated from the crankshaft. The journal for one separated rod exhibited thermal damage consistent with lubrication distress. No. 4 cylinder showed normal signatures; No. 3 was partially visible and appeared normal.
The fuel pump, fuel lines, and throttle assembly were intact with no leaks. The oil pump, filter, and sump were intact with no external leaks. The quick oil drain valve was closed. The oil sump contained about 2 quarts of oil. Metallic material consistent with bearing, piston, and crankcase material was found in the sump, with bearing pieces showing thermal damage. The oil pick-up tube was partially visible with no anomalies. The oil filter contained metallic material. The oil cooler and all oil lines were secure with no leaks. The propeller flange was attached without cracks; the crankshaft could be rotated manually with resistance, and rotational continuity was established throughout the engine and valve train.