History of Flight
On December 8, 2012, at 1334 eastern standard time, a Cessna 421C, registration N297DB, operated by a private individual, was destroyed when it collided with trees and terrain following a loss of control after takeoff from North Palm Beach County Airpark (LNA) in Lantana, Florida. The commercial pilot was fatally injured. Visual meteorological conditions prevailed, and no flight plan was filed for the personal flight conducted under 14 CFR Part 91.
The pilot had taken delivery of the airplane from a maintenance facility that had just completed an annual inspection and repainting. After performing a preflight inspection, the pilot started the airplane but shut it down to resolve an alternator charging light. He then stated he planned to fly to Okeechobee, Florida, complete a few landings, and continue to Miami. A ground run of several minutes preceded taxi to the approach end of Runway 3 for takeoff. The airplane lifted off about halfway down the runway and climbed at a normal rate. The mechanic present observed the airplane suddenly yaw left for a second or two, then the nose continued to pitch up before rolling left and descending vertically, nose-down, until it disappeared from view. Several witnesses provided similar accounts, with one certificated flight instructor reporting that the airplane kept pitching up and appeared to experience a VMC roll.
Personnel Information
The pilot held a commercial pilot certificate with ratings for airplane single-engine land and sea, airplane multiengine land, and instrument airplane. His most recent FAA third-class medical certificate was issued on February 27, 2008. The pilot's logbook showed 1,217 total flight hours, of which 175 were in multiengine airplanes.
Aircraft Information
The airplane, manufactured in 1980, had its most recent annual inspection completed on December 3, 2012, at 7,039.9 aircraft hours. It had accrued 2.2 flight hours after the inspection. The No. 2 (right) engine was overhauled on September 13, 2006, and had 966.3 hours since major overhaul (SMOH) at the inspection. The No. 1 (left) engine was overhauled on October 16, 2009, and had 312.6 hours SMOH. Oil samples taken at the inspection showed normal values. The maintenance facility owner, who held commercial pilot and mechanic certificates, performed a test flight with the pilot after the inspection. During that flight, the left engine showed RPM above maximum when right was at maximum, and fuel flow on left was 1.5-2.0 gallons per hour below right and below prescribed guidance. The left alternator segment light illuminated mid-flight but later extinguished. After landing, the pilot was told that propeller RPM and fuel flow needed adjustment on the left engine only. Corrections were made, and a complete run-up was performed prior to delivery.
Meteorological Conditions
At 1332, weather at Palm Beach International Airport (PBI), 5 miles north of LNA, included a scattered cloud layer at 2,600 feet and a broken ceiling at 3,500 feet. Wind was from 110 degrees at 11 knots. Temperature was 27°C, dew point 20°C, and altimeter setting 29.97 inches of mercury.
Wreckage and Impact
The wreckage was examined on December 9, 2012. All major components were accounted for. The airplane was consumed by postimpact fire back to the aft pressure bulkhead. Wing spars were intact, and control cable continuity was established from cockpit to flight control surfaces. Main landing gear actuators were consistent with a down-and-locked configuration. Both engines were significantly damaged by postcrash fire. All three left propeller blades were attached and feathered. Right engine propeller blades were destroyed; remaining blades showed low pitch positions. The right fuel selector valve was in the main position; the left fuel selector valve was in the off position. Preliminary examinations of both engines revealed continuity and no mechanical anomalies; engines were retained for detailed examination.
Medical and Pathological Findings
The autopsy revealed blunt force and thermal injuries as cause of death. Toxicological testing detected 30% carbon monoxide and 3.86 µg/ml cyanide, consistent with exposure to combustion products.
Tests and Research
Detailed engine examinations were conducted February 19-22, 2013. Each engine was a 520-cubic-inch, six-cylinder, turbocharged, geared engine producing 375 hp. The right engine showed no preimpact mechanical anomalies. The left engine exhibited signatures consistent with piston dome-to-valve contact. Crankcase halves were separated; the No. 1 cylinder main bearing was rotated, severely damaged and distorted, with bearing fragments in the oil sump. No. 3 main bearing showed accelerated wear and wiping of Babbitt material. Damage consistent with oil starvation was evident on No. 1 and No. 3 main bearing journals and No. 1 and No. 2 connecting rod journals. The camshaft gear had five sheared teeth. Maintenance records indicated that manufacturer's main and rod bearings were installed during overhaul, and no maintenance requiring breaking crankcase thru-bolt torques had been performed since overhaul. The annual inspection invoice included a write-up to investigate no oil pressure on the left engine and to reprime the left oil pump, filter, and standpipe. The maintenance facility noted that engines sat idle for weeks during inspection and painting, causing oil to settle and the pump to lose prime; motoring the left engine showed no oil pressure, so the system was primed before start.