DEN07FA022 · Cessna 337C

A witness to the accident said the airplane touched down on runway 21, then suddenly veered to the right. It went off the runway, crossed the median and parallel taxiway, across the parking ramp, and collided with a hangar "at a high rate of speed." A sign, a pickup truck parked outside, and an airplane inside the hangar were also damaged. After the collision, the rear engine continued to run at full power. The witness drove to the accident site and tried to gain access to the cockpit from outside the airplane in an attempt to shut the engine down. When this failed, he went inside the hangar, and tried to reach inside the cockpit. The engine quit running shortly thereafter. Another witness said he heard the airplane's engines running at "full throttle" and saw the airplane "hopping and fishtailing" across the ground. When he arrived at the accident site, the rear propeller was striking a blue-colored pickup truck parked next to the hangar, and oil was "spraying everywhere." The engine eventually shut down, and the propeller moved to the feathered position. The airplane was pulled from the hangar and examined. No discrepancies were noted with the steering and brake systems. According to the pilot's autopsy report, the pathologist found "focal, severe hardening (atherosclerosis) of the aorta within the abdomen. The heart showed changes (fibrosis) consistent with a previous ischemic episode (heart attack)." The pathologist opined, "Given the severity of hardening of the coronary arteries of the heart, it is possible that the decedent was in the early stages of a heart attack (coronary artery insufficiency). Changes of ischemia (impaired blood flow) in the heart muscle often take hours to become evident under the microscope; therefore, the decedent may have experienced some decrease blood flow to the heart without microscopic evidence at autopsy. Decreased blood flow due to coronary insufficiency can cause irregular heartbeat and/or unconsciousness rapidly." Toxicology protocol was performed by FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma. According to their report, diltiazem was present in the blood and liver. According to the Kaiser Permanente Drug Encyclopedia, diltiazem is a calcium channel blocker, and is used to treat high blood pressure (hypertension) and chest pain (angina). It may also be used to treat an irregular heartbeat.

Verbatim NTSB analysis and probable cause from the NTSB dataset