History of Flight
On March 17, 2019, at approximately 1745 eastern daylight time, a Cessna 421B airplane, registration N424TW, was destroyed when it impacted terrain near Plain City, Ohio. The pilot, the sole occupant, was fatally injured. The flight was conducted as a personal flight under Title 14 Code of Federal Regulations Part 91.
The pilot departed from James M. Cox Dayton International Airport (DAY) in Dayton, Ohio, on a short cross-country flight. Radar and radio communications data show that the pilot contacted air traffic control at 1717 shortly after takeoff. At 1729, the pilot was given a frequency change and subsequently requested the RNAV runway 28 approach at Delaware Municipal Airport (DLZ), about 55 nautical miles east-northeast of DAY. About two minutes later, the controller advised of weather ahead, and the pilot accepted a 15° course deviation. At 1735, the controller issued a heading of 090° and instructed the pilot to maintain 3,000 feet mean sea level (msl), which was acknowledged. About one minute later, the pilot reported that the airplane was "picking up icing" and needed to "pick up speed." The controller cleared the airplane to descend to 2,500 feet and asked if it was clear of clouds; the pilot replied negatively. At about 1739, noting the airplane was climbing, the controller cleared it to 6,000 feet with approval for deviations left or right. The controller then issued a low altitude alert. The pilot acknowledged, stating he was climbing. At about 1740, the controller requested the pilot's altitude as the transponder signal was lost. No further communications were received.
Recovered data from the onboard avionics indicate that about 17 minutes after takeoff, the indicated airspeed began to decay while groundspeed remained steady. About one minute later, fuel flow increased from 38 to 60 gallons per hour, consistent with increased power. At that time, indicated airspeed had decayed to about 100 knots, with groundspeed around 150 knots. During the final 2.5 minutes, the airplane was in a left turn, climbed to about 3,500 feet msl, then began descending at about 5,000 feet per minute. "SINK RATE" and "PULL UP PULL UP" annunciations were recorded. The descent was arrested about 300 feet above ground level (agl). The airplane then entered two additional climb/descent cycles with similar annunciations, but the pilot did not recover from the third descent. During these events, groundspeed, and likely airspeed, exceeded the maneuvering speed (Va) of 150 knots, and during the first and final sink rate annunciations, groundspeed exceeded the maximum structural cruising speed (Vno) of 200 knots.
Pilot Information
The pilot was a former U.S. Air Force pilot and test pilot with over 3,000 hours of military flight experience.
Aircraft Information
The Cessna 421B, manufactured in 1974, was certified for flight into known icing conditions.
Meteorological Information
At 1735, the automated weather observation at Union County Airport (MRT), Marysville, Ohio, about 8 miles northwest of the accident site, reported calm wind, 3 miles visibility, broken clouds at 400 feet agl, overcast at 1,200 feet agl, temperature 34°F, dew point 32°F, and an altimeter setting of 30.19 inches of mercury.
Wreckage and Impact Information
The airplane impacted a field about 7 miles southwest of DLZ. Ground scars and wreckage were consistent with a left-wing-low attitude at impact. The wreckage path was oriented on about a 140° heading, crossed a two-lane road, and struck two wooden utility poles. The main wreckage came to rest at the base of the second pole, about 395 feet from the initial impact. The wreckage path was about 850 feet long, with the airplane highly fragmented. There was no postcrash fire.
All major components were located at the site, but flight control continuity could not be confirmed due to fragmentation. The cockpit and instrument panel were extensively damaged. Landing gear and flap positions could not be determined from cockpit controls.
Both engines separated from the wings. The first engine, found near the utility poles, sustained heavy impact damage, with most components separated. The crankshaft could not be rotated by hand. The second engine, near the end of the wreckage path, also sustained heavy impact damage. No pre-impact abnormalities were noted in the fuel systems, spark plugs, or other examined components. Both three-bladed propellers separated from their engines. One propeller's blades were separated from the hub, exhibiting twisting and leading-edge polishing; the other propeller's blades remained in the hub with similar signatures.
Despite impact damage limiting some examinations, no pre-impact airframe, engine, or systems anomalies were found that would have precluded normal operation. The pitot-static and deicing systems were too damaged for functional testing.
Medical and Pathological Information
An autopsy by the Montgomery County Coroner's Office determined the cause of death as multiple blunt force injuries. Toxicological testing by the FAA Forensic Sciences Laboratory was negative for ethanol and tested drugs; specimens were not tested for carbon monoxide or cyanide.