Accident Overview
On November 29, 2018, at 1855 eastern standard time, a Cirrus SR-22, registration N597CP, sustained substantial damage after impacting terrain near Kennesaw, Georgia. The accident occurred following the deployment of the Cirrus Airframe Parachute System (CAPS) during an emergency descent. The private pilot and a passenger received minor injuries. The aircraft was operated by Cavern Aviation LLC under Part 91 as a personal flight. Night visual meteorological conditions prevailed, and a visual flight rules flight plan had been filed. The flight originated from Johnson County Executive Airport (OJC) in Olathe, Kansas, around 1610, with a destination of Dekalb-Peachtree Airport (PDK) in Chamblee, Georgia.
Pilot and Aircraft Information
The pilot held a private pilot certificate with instrument airplane privileges and an FAA third-class medical certificate issued in January 2014. He reported 899 total flight hours, all in the accident aircraft, and his most recent flight review was in October 2017. The low-wing airplane was powered by a Continental Motors IO-550-N engine equipped with a Tornado Alley Turbo turbonormalizing system. The most recent annual and 100-hour inspections were completed in October 2018. A Cirrus Recoverable Data Module (RDM) was recovered but contained data only from more than three years prior to the accident. A mandatory service bulletin (SB 2X-31-05 R2) required replacing the RDM to correct a software issue; the installed RDM had an older part number.
Engine Failure Sequence
The pilot reported that during descent from 17,500 ft msl, at about 7,000 ft msl and 20 nautical miles from PDK, the engine experienced a jolt followed by a low oil pressure warning. All engine instruments had been normal before this event. The pilot reduced throttle and declared an intention to divert to Cobb County International Airport (RYY) in Kennesaw, Georgia. While on an extended base leg for runway 27 at RYY, at about 2,000 ft msl, a second engine jolt occurred with sparks from the cowling. Shortly after, a third jolt resulted in a complete loss of engine power. Unable to identify a clear landing area, the pilot activated the CAPS and prepared for impact. The parachute deployed, and the aircraft struck trees and terrain.
Engine data from the primary flight display corroborated the pilot's account. About six minutes before the power loss, oil pressure dropped from 44 psi to 15 psi over one minute, then gradually declined to zero. All other engine parameters remained nominal until the power loss.
Examination Findings
An FAA inspector examined the aircraft at the accident site. The CAPS had deployed, and the aircraft came to rest upright after impacting trees. The fuselage, wings, and empennage sustained substantial damage. The engine crankcase at the No. 6 cylinder had a fracture hole, and the connecting rod was sheared from the upper crankshaft bearing. No evidence of oil spray along the fuselage or windscreen was observed. Fragments of the upper cowling were found about 720 ft northwest of the main wreckage.
Engine examination revealed internal mechanical damage preventing rotation by hand. Intake and exhaust valves were intact with normal combustion signatures. Spark plugs showed normal operation, magnetos functioned normally, fuel pump rotated freely, and the fuel manifold valve screen had no debris. Several connecting rods and bearings were damaged with signs of extreme heat. The oil pump gears were intact, but metal contaminants were found in the oil filter, and the pump housing showed damage from hard particle passage. The oil sump had small protrusions from the inside, and removed contents included damaged connecting rod ends, valve lifters, and bearings.
The left turbocharger could not be rotated by hand, with rub marks and blade tip damage on turbine and compressor wheels, indicating rotation during contact. Its oil supply check valves functioned properly. The right turbocharger rotated freely with no notable damage, and its check valves also operated normally.
Weather conditions at RYY at 1848 included visibility 10 statute miles, scattered clouds at 4,000 ft agl, broken clouds at 5,000 ft and 9,000 ft agl, wind from 050° at 4 knots, temperature 11°C, dew point 4°C, and barometric pressure 30.08 inHg. The end of civil twilight was at 1756.
A maintenance record from the October 2018 100-hour inspection noted an oil intake leak on the left turbocharger, requiring gasket replacement. On November 15, 2018, the oil and filter were replaced, and no leaks were found during engine run-up.