Accident Summary
On April 18, 2015, about 1300 eastern daylight time, a Cessna LC41-550FG, registration N400BZ, was substantially damaged by fire following an emergency landing at Space Coast Regional Airport (TIX) in Titusville, Florida. The private pilot, a pilot-rated passenger, and an additional passenger were uninjured. Visual meteorological conditions prevailed, and an instrument flight rules flight plan was filed for the cross-country flight, which departed Savannah/Hilton Head International Airport (SAV) around 1145 and was destined for Okeechobee County Airport (OBE). The flight was conducted under 14 CFR Part 91.
Flight and Emergency
According to the pilot, he planned to fly to OBE for a 50-hour service and cosmetic maintenance. During preflight, he noted about 7 quarts of oil in the sump. Approximately one hour into the flight, while descending to 8,000 feet mean sea level (msl), the pilot observed the oil pressure decrease into the red, with other instruments normal. He reported the loss to air traffic control, and about one minute later, oil pressure dropped to zero. The pilot identified TIX as the nearest airport and began an emergency descent. As the airplane reached about 3,000 feet msl, the engine lost all power and smoke entered the cabin through the air vents. The pilot performed a forced landing to runway 27. After the airplane came to rest, flames were observed coming from the cowling. The pilot and passengers egressed before the fire consumed most of the fuselage.
Examination and Fire Damage
Examination by an FAA inspector revealed that the engine cowling was destroyed by fire, and portions of the airframe and cabin area were substantially damaged. The No. 3 cylinder exhaust valve rocker box cover was missing, and three screws were missing from the No. 4 cylinder exhaust rocker box cover; one screw was missing from the No. 4 intake cover, but no gap was observed. The No. 2 exhaust rocker box cover was loose, though all its screws were present. On-scene examination by representatives of the engine and airframe manufacturer, under FAA supervision, showed soot on the No. 3 cylinder rocker arm and head surfaces, a small hole in the right crankcase half near the No. 5 cylinder base, and a similar hole on the left near the No. 4 cylinder base. The through-bolt nut to the top rear crankcase was missing, and the through-bolt head had backed off about 1/2 inch; all six cylinders remained attached. The forward oil sump was destroyed by fire; the oil rod had a small amount of dark viscous liquid, and the quick drain valve was closed and safety-wired. The oil cooler and filter were intact with thermal damage; the oil pressure sending unit was destroyed.
Engine Disassembly
At the engine manufacturer's facility, the crankcase displayed multiple puncture holes. Disassembly revealed all six connecting rods had separated from the crankshaft at their journals. Multiple main oil journals were dry and heat-discolored, consistent with oil starvation. The oil sump contained metallic fragments. Main bearing journals appeared blue; connecting rod journals were rusted with rotational scoring. The camshaft was broken at the No. 5/No. 6 cylinder position.
Pilot and Maintenance Information
The pilot reported he was unaware the rocker box covers were loose and had not removed them during his ownership. He noted the airplane required only one quart of oil in the preceding 20 hours and had been flying well. The airplane, manufactured in 2008, was a four-seat, low-wing, fixed-gear model powered by a Continental Motors TSIO-550-C, 310-horsepower engine. The pilot purchased it in February 2015. The most recent annual inspection was on June 13, 2014, at 459 total airframe hours (43 hours before the accident). A pre-buy inspection on February 6, 2015, did not include removal of the rocker box covers.
Propeller Strike History
On October 31, 2011, the engine was disassembled and inspected following a propeller strike. The maintenance entry stated it was disassembled, cleaned, and parts inspected per the manufacturer's overhaul manual and applicable service bulletins. It was reassembled with new main bearings, rod bearings, rod bolts/nuts, seals, gaskets, and a new camshaft and lifters. At that time, Service Bulletin 96-11B required complete disassembly and inspection of rotating components after a propeller strike; the overhaul manual also mandated disassembly per Chapters 12 and 13, which include removing rocker box covers from all cylinders.
Flight Data Recorder Information
The airplane was equipped with a Garmin G1000 that recorded engine and flight data. Data showed takeoff at 1135:35, with rpm increasing to 2,550. The flight was uneventful until about 1249:30, when oil pressure began a steady decline. At 1253:10, oil pressure reached 0 psi at approximately 8,000 feet pressure altitude during a descent from 10,000 feet. Over the next 2 minutes 30 seconds, exhaust gas temperatures for each cylinder rose slightly then decreased to about 400°F. The airplane reached a pressure altitude of 0 feet at 12:57:00; indicated airspeed dropped to 0 knots about 30 seconds later.